[RE-wrenches] Access pathways (Rebecca Lundberg)
Hi, Rebecca. Based on the numbering systems and language, MN has incorporate NFPA 1: Fire Code requirements at the state level. The language and requirements in the International Fire Code are similar. You can access a free PDF version of NFPA 1 here: http://www.nfpa.org/codes-and-standards/document-information-pages?mode=code=1 <http://www.nfpa.org/codes-and-standards/document-information-pages?mode=code=1> When it comes to enforcement, there are important differences between NFPA 70 (aka National Electrical Code) requirements and those in NFPA 1. If the NEC says you have to provide rapid shutdown, for example, then chances are your AHJ will require that you meet these requirements. However, if the Fire Code says that you need to provide a 3’ setback on residential roofs, there are a number of scenarios where an AHJ might not require this in practice. These include situations where: access to adjacent roof planes provides firefighters with adequate opportunities for roof ventilation [typically determined in real time on a case-by-case basis] the local fire department does not fight residential structure fires by ventilating roofs [typically determined in advance at the jurisdiction level] the roof or structure is smaller than some pre-determined amount [typically determined at the jurisdiction level] the local fire marshall has adopted less restrictive access requirements (perhaps 12” rather than 36”) [typically determined at the jurisdiction level] It’s entirely possible to get stakeholders together adapt the fire code requirements at the city, county or even state level. It is also possible to adapt the requirements on a case-by-case basis. The latter is obviously more work for everyone. The main point is that complying with fire codes can be be more of a conversation than complying with the NEC. Here’s a link to an article that discusses both the residential fire code requirements as well as a variety of compliance and enforcement strategies: http://solarprofessional.com/articles/design-installation/pitched-roof-array-layout-for-fire-code-compliance?v=disable_pagination <http://solarprofessional.com/articles/design-installation/pitched-roof-array-layout-for-fire-code-compliance?v=disable_pagination> If you’d like a PDF copy of the article, just send me a direct message. David Brearley Senior Technical Editor, SolarPro NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Follow us on Twitter: @SolarPro Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh > On Mar 26, 2016, at 1:04 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: > > Send RE-wrenches mailing list submissions to > re-wrenches@lists.re-wrenches.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org > or, via email, send a message with subject or body 'help' to > re-wrenches-requ...@lists.re-wrenches.org > > You can reach the person managing the list at > re-wrenches-ow...@lists.re-wrenches.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of RE-wrenches digest..." > When responding to posts within the Digest, be sure to restore the Subject: > line to the original, and please edit out any extraneous lines from the > quoted message. > Today's Topics: > > 1. Access pathways (Rebecca Lundberg) > > From: Rebecca Lundberg <rebecca.lundb...@powerfullygreen.com> > Subject: [RE-wrenches] Access pathways > Date: March 25, 2016 at 10:04:31 PM CDT > To: "re-wrenches@lists.re-wrenches.org" <re-wrenches@lists.re-wrenches.org> > Reply-To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > > > Dear Solar Colleagues, > > I know the building code language regarding PV installations providing 3' > access pathways was proposed and adopted in several states a few years ago. > > "3113.1.2.1 Residential buildings with hip roof layouts. Panels or modules > installed on residential buildings with hip roof layouts shall be located in > a manner that provides a 3-foot-wide (914 mm) clear access pathway from the > eave to the ridge on each roof slope where panels/modules are located. The > access pathway shall be located at a location on the building capable of > supporting the live load of firefighters accessing the roof." (this is just a > partial quote from here https://www.revisor.mn.gov/rules/?id=1305.3113 > <https://www.revisor.mn.gov/rules/?id=1305.3113>) > > This is a newly adopted code addition in MN, and there was absolutely no > discussion with the solar industry. In MN we install solar on the > south-facing roof as optimal, with perhaps the SE, SW, or even
Re: [RE-wrenches] to flash or not to flash
It may be helpful to distinguish between exposed-fastener metal roofs and other roofing systems. If you’re working on a metal roof that is attached with exposed fasteners, I don’t know of any practical solution for retrofitting PV without adding more exposed fasteners. And, yes, the mastic under the L-foot will likely outlast the waterproofing around the roof attachments. However, according to conversations I’ve had with James Kirby, exposed fastener metal roofs are not an NRCA-approved/recognized roofing system. The waterproofing methods on exposed-fastener metal roofs are inherently inconsistent with NRCA standards. Other roofing systems are consistent with NRCA standards. If you don’t use flashing with these NRCA-approved roofing systems, your PV attachment method is going to compromise the waterproofing for the roof system. You can’t really argue that point, because there are established standards that apply to flashing and waterproofing according to roof type. David Brearley Senior Technical Editor, SolarPro NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Follow us on Twitter: @SolarPro Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] Environmental extremes (high snow, wind or corrosivity)
Greetings wrenches, Anyone have any photos they'd like to share for an interview-based article in SolarPro about designing PV systems for extreme environments? For the purposes of this article, we’re focusing on mechanical loads and stresses. Think high design wind speeds (Florida), high snow loads (high elevations and latitudes), and coastal corrosion. We’re interested in both: Photos of best practices, Photos of common mistakes And photos of field failures (separated frames, laminates sucked out of frames, broken modules, etc.) Generally speaking, we run photos of the best practices with a courtesy credit and photos of failures anonymously without a credit. In terms of field failures, I think damages resulting from an act of God are just as interesting to installers as photos of avoidable damages. We can clarify which is which in the caption. If you have any photos or expertise you’d like to share, please contact me directly via email: david.brear...@solarprofessional.com mailto:david.brear...@solarprofessional.com Thanks! David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Follow us on Twitter: @SolarPro Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] UL 1703 coming to California
August, Here's some additional info: http://solarprofessional.com/articles/design-installation/fire-classification-for-roof-mounted-pv-systems?v=disable_pagination Best regards, David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh On Dec 9, 2014, at 7:50 AM, re-wrenches-requ...@lists.re-wrenches.org wrote: Send RE-wrenches mailing list submissions to re-wrenches@lists.re-wrenches.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org or, via email, send a message with subject or body 'help' to re-wrenches-requ...@lists.re-wrenches.org You can reach the person managing the list at re-wrenches-ow...@lists.re-wrenches.org When replying, please edit your Subject line so it is more specific than Re: Contents of RE-wrenches digest... When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message. Today's Topics: 1. UL 1703 coming to California - anyone ready? (August Goers) 2. Re: UL 1703 coming to California - anyone ready? (August Goers) 3. Re: UL 1703 coming to California - anyone ready? (Glenn Burt) 4. Re: Magnum Back Plates (Baxter, Gary) From: August Goers aug...@luminalt.com Subject: [RE-wrenches] UL 1703 coming to California - anyone ready? Date: December 8, 2014 5:07:54 PM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org Hi All California Wrenches, As far as I understand, UL 1703 goes into law in California on Jan 1, 2015 and will require new fire rating classifications for many projects. Is anyone else currently planning what racking and modules they will be using to meet these requirements? I’ve been trying to get my head around this for a while now and I’m having a hard time finding substantial information from both racking and module manufacturers. A little info: http://osfm.fire.ca.gov/informationbulletin/pdf/2014/IB14002PVFireClassification.pdf Best, August Luminalt From: August Goers aug...@luminalt.com Subject: Re: [RE-wrenches] UL 1703 coming to California - anyone ready? Date: December 8, 2014 6:48:34 PM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org All – Bill Brooks wrote back to me and shared a draft NREL whitepaper on fire performance of PV systems he wrote. If you are interested, please contact me off list and I will share it with you (he said it was okay to share). Best, August From: August Goers [mailto:aug...@luminalt.com] Sent: Monday, December 08, 2014 3:08 PM To: 'RE-wrenches' Subject: [RE-wrenches] UL 1703 coming to California - anyone ready? Hi All California Wrenches, As far as I understand, UL 1703 goes into law in California on Jan 1, 2015 and will require new fire rating classifications for many projects. Is anyone else currently planning what racking and modules they will be using to meet these requirements? I’ve been trying to get my head around this for a while now and I’m having a hard time finding substantial information from both racking and module manufacturers. A little info: http://osfm.fire.ca.gov/informationbulletin/pdf/2014/IB14002PVFireClassification.pdf Best, August Luminalt From: Glenn Burt glenn.b...@glbcc.com Subject: Re: [RE-wrenches] UL 1703 coming to California - anyone ready? Date: December 8, 2014 7:14:01 PM CST To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Reply-To: glenn.b...@glbcc.com, RE-wrenches re-wrenches@lists.re-wrenches.org I think Quick Mount did a presentation covering this not too long ago. Maybe it is up on their website now. – indeed it is under Roofing Codes for Solar, from their Resources Support links. HTH Glenn From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of August Goers Sent: Monday, December 08, 2014 7:49 PM To: RE-wrenches Subject: Re: [RE-wrenches] UL 1703 coming to California - anyone ready? All – Bill Brooks wrote back to me and shared a draft NREL whitepaper on fire performance of PV systems he wrote. If you are interested, please contact me off list and I will share it with you (he said it was okay to share). Best, August From: August Goers [mailto:aug...@luminalt.com] Sent: Monday, December 08, 2014 3:08 PM To: 'RE-wrenches' Subject: [RE-wrenches] UL 1703 coming to California - anyone ready? Hi All California Wrenches, As far as I understand, UL 1703 goes into law in California on Jan 1, 2015 and will require new fire rating classifications
Re: [RE-wrenches] SPI 2014
Daniel, Here's some of what I learned about solutions for 690.12. Residential rapid shutdown SMA's TL-US series inverters can meet the 10 second requirement in 690.12 without further mediation. Therefore you can meet 690.12 with these string inverters by adding a ground-level rapid shutdown controller (an e-stop button) and a rooftop rapid shutdown box (a pass-through wiring box w/ contactors to open each source circuit conductor.) While SMA may be working on an in-house solution for these components, Bentek solar has a third-party solution that will be available very soon: http://www.bentek.com/solar-products/disconnect-systems/rapid-shutdown-systems/ This same product works w/ ABB UNO-series inverters, which can also meet the 10-second requirement w/out additional mediation. It sounds like these products will run about $700 in the short-term, but are expected to sell for less than $500 as demand scales. Commercial rapid shutdown Many companies are leading with low-profile inverter skids that allow 3-phase string inverters to be located on a commercial rooftop w/in the array field. In some cases, these mounting products are offered from the inverter company (AE), but there are also many third-party providers (SolarBOS, Bentek, etc.) w/ solutions for ABB inverters, SMA inverters, etc. The motivation to put string inverters on commercial rooftops is largely driven by the cost of arc-fault rapid shutdown enabled combiners. If you want to use a central inverter, it looks like you'll have to spend 2X as much money on your source circuit combiners as you are now in order to meet these code requirements. David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh On Oct 29, 2014, at 12:45 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Daniel Young dyo...@dovetailsolar.com Subject: Re: [RE-wrenches] SPI 14 Post Show Request for Comments Date: October 29, 2014 9:34:48 AM CDT To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org I too am interested. Especially after the teaser from SMA that they would unveil their solution to the 2014 NEC 690.12 fiasco at the show. I see nothing on SMA's website as of yet. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 NABCEP Certified Solar Heating InstallerTM: Cert #SH031409-13 -Original Message- From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Loesch Sent: Wednesday, October 29, 2014 8:21 AM To: RE-wrenches Subject: [RE-wrenches] SPI 14 Post Show Request for Comments Gentlemen Ladies, Anyone who went to the LAS show have any comments? Hopefully, not everything that happens in Vegas stays in Vegas. Thanks for sharing, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] SPI 2014
Hi Daniel, You should patent that magic box idea. Better yet, patent the J-box with an embedded addressable semiconductor switch: Permissive signal from the inverter = switch closed; no signal from the inverter = switch open. Bob's your uncle. Touch-safe PV modules without undue cost or complexity. (That was the magic box I was hoping for but did not see.) I am also concerned about the cost impact of 690.12. On the one hand, we have all these great SunShot initiatives to drive down the cost of solar. On the other hand, we have these new Code requirements that are driving a cost back into the BOS. As a result, it sometimes feels like the one hand doesn't know what the other hand is doing. (That's part of what makes life on the solarcoaster so exciting! ;-) BTW: I ran into one of your customers (virtually)—the one with a 12 kW ground-mounted residential system in Yellow Springs, Ohio—on a coffee nerd forum. I forget how the PV system came up, but the guy clearly has good taste in espresso equipment and PV installers. Keep up the good work! Best regards, David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh On Oct 29, 2014, at 2:45 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Daniel Young dyo...@dovetailsolar.com Subject: Re: [RE-wrenches] SPI 2014 Date: October 29, 2014 2:24:09 PM CDT To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org Thanks for the response David, this is what I was kind of expecting. I was hoping for some sort of “magic box” that attached to the first, and last module in the string, and would shut the string down if it lost signal from the inverter. Similar to how solar edge works, but with only 1-2 units/string. I like Solar Edge, but we try very hard to offer US made equipment as our primary offering. Right now it seems that 690.12 is just increasing the US made premium, to the point where I don’t imagine US inverters will be even 5% of our residential installation base next year when 2014 NEC hits the majority of our jurisdictions. Makes me sad. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 NABCEP Certified Solar Heating InstallerTM: Cert #SH031409-13 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] Fall Protection Recommendations?
Hi Bill, Joey Krys not only sells a lot of fall protection equipment, but also understands some of the unique requirements of PV contractors: Joey Krys ToolUp Professional Contractor Supplies Sales / Fall Protection Specialist Mobile: 858-864-2821 Office: 858-565-2284 Fax: 858-565-2903 Email: j...@toolup.com Best regards, David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 Check out this AMAZING music video tribute to SolarPro: http://bit.ly/1qfMCCh On Oct 6, 2014, at 3:09 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: Send RE-wrenches mailing list submissions to re-wrenches@lists.re-wrenches.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org or, via email, send a message with subject or body 'help' to re-wrenches-requ...@lists.re-wrenches.org You can reach the person managing the list at re-wrenches-ow...@lists.re-wrenches.org When replying, please edit your Subject line so it is more specific than Re: Contents of RE-wrenches digest... When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message. Today's Topics: 1. Re: Fall Protection Recommendations? (Tump) 2. Thirsty batteries: Daily absorb cycles on top of gridpowered float (Mick Abraham) 3. Re: Thirsty batteries: Daily absorb cycles on top of grid powered float (Roy Butler) 4. Re: Thirsty batteries: Daily absorb cycles on top of grid powered float (Rebekah Hren) 5. SWRC for older Power Series inverter (Chris Daum) 6. Re: Thirsty batteries: Daily absorb cycles on top of grid powered float (jay peltz) 7. Re: SWRC for older Power Series inverter (Allan Sindelar) 8. TL inverter with long DC Feeder (William Miller) 9. Re: TL inverter with long DC Feeder (Benn Kilburn) 10. Re: TL inverter with long DC Feeder (All Solar, Inc.) 11. Re: TL inverter with long DC Feeder (Mark Westbrock) 12. Re: TL inverter with long DC Feeder (Michael Kelly) From: Tump t...@swnl.net Subject: Re: [RE-wrenches] Fall Protection Recommendations? Date: October 6, 2014 3:29:50 AM PDT To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org I certainly do. We use DBI-Sala safety equipment despite the POOR sales rep and my local supplier, the equipment is first rate. When one is selecting devices for LIFE SAVING WORK safety at the cost of ~2K for 2 persons, I would have thought their rep would have been more attentive. We even called him and asked for to bring the type of harness we were interested in but it seemed he was more interested in his smart phone, NOT Salas liability for wrong harnesses or incorrect fit. We use harnesses that have front and rear d rings, retractable 9' lanyards + the horizontal life line that makes working with another person quite easy. The life line we use is rated for no more then 2 persons but they do have other ones available. The harness have very easy adjustment that are lockable w/ w/o shoulder padding., good fit light weight. The biggest problem we had was again the LACK (or willingness to educate) of knowledgable sales reps! Once you place the order you're stuck w/ what you get. This is why I was/am so hesitant to recommend this company NOT the quality, but the lack interest of their NE sales rep in regards to selling us the right gear, and the fitting training Additional info please feel free to contact me off list, I do get pissed at the lack of their support so I have spent quite a bit of time researching this stuff. On Oct 5, 2014, at 12:33 PM, William Dorsett wrote: The Home Depot safety harnesses are very clumsy to work in, difficult to adjust for different workers and don’t easily adapt for multiple workers. Is there any consensus as to the best safety equipment for a crew of four or five on a roof? Thanks all. image002.jpg Bill Dorsett.vcf___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org t...@swnl.net www.SWNL.net Solarwinds Northernlights Serving Mid Coast Maine Northern California 207-832-7574 Cl. 610-517-8401
Re: [RE-wrenches] Solar Module fire ratings
There are several SolarABCs reports that speak to this. For example: http://bit.ly/1bD8wM7 The complete list of reports is found here: http://www.solarabcs.org/current-issues/fire_class_rating.html David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 On Feb 7, 2014, at 8:55 AM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Bill Loesch solar1onl...@charter.net Subject: Re: [RE-wrenches] Solar Module fire ratings Date: February 7, 2014 8:54:22 AM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org Hi David, Can you elaborate on the mounting system(s?) that would minimize fire propagation? TIA, Bill Loesch Solar 1 - Saint Louis Solar 314 631 1094 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Solar Module fire ratings
William, There are few Class A fire-rated PV modules on the market today: http://www.trinasolar.com/us/product/PDG5.html http://www.silicon-energy.com/products/modules The broader context is that UL is in the process of revising the way that fire ratings are determined for PV systems. To date, modules have received a fire classification. However in the installed environment, fire propagation has more to do with the mounting system than with module construction. Therefore, fire classification tests in the future will be based more on the mounting method. As Bill Brooks explained here on January 8th: UL 1703 has been substantially changed as to how modules are fire rated. Basically, modules will no longer receive a direct fire rating unless they are installed in a fire-rated mounting system. A current module with a Class C or Class A rating will no longer have that rating. The mounting system will carry the fire rating. Modules will have specific “types” based on their construction. This way a rack manufacturer can get a fire rating on modules of a particular module construction type and not have to rerate their rack with every module that has that same construction. All these changes in the UL1703 standard are going to require education so that fire officials and building code enforcement officials understand how to enforce the new building code rules in light of the new version of the UL standard. Arguably, enforcement of fire rating requirements in the I-codes is running ahead of the development of the applicable UL standard. It's safe to say that working groups at SEIA and SolarABCs are very interested in tracking these types of issues. The SolarABCs has had fire classification ratings on its radar for several years now: http://www.solarabcs.org/current-issues/fire_class_rating.html David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 On Feb 6, 2014, at 12:20 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: William Korthof wkort...@gmail.com Subject: [RE-wrenches] Solar Module fire ratings Date: February 6, 2014 10:56:05 AM CST To: re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org I've just been informed by a city (our own City in fact) that is asking for minimum Class-B fire-rated solar modules, citing rules newly adopted Jan 1, 2014. The expert behind the counter made reference to IRC section 902.4, which seems to call for solar installations to meet the same fire rating standard as the roofing on which they are installed. It was the end of the day. Most roofing is B or A rating apparently, and my official was adamant that this meant only a B or A rated panel would be allowed. As far as I know, virtually every solar panel I've ever handled going back to the mid 90's was Class C rated. The only Class A I remember (and the only one I noticed from web searching) was the obnoxiously unwieldy glass-on-glass 300-watt series that got absorbed by Schott and probably discontinued many years ago. I have one of those antiques in my shop for fun, and I encountered exactly one installation that used the product (from another installer), and there were issues with the panels within the first 10 years. Is this Class A/B requirement issue true? Did the state fire marshall adopt a policy at the start of this year that basically bans all panels with C rating? Are there any class B or A rated modules on the market? Who's brilliant idea was this? /wk -- William Korthof 714.875.3576 and 800.524.2970 Sustainable Solutions Partners (also dba: EE Solar) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] NEC 2014 690.12 Rapid Shutdown
Wrenches, Matt Paiss is wanted to chime in here. He's a member of the Code-Making Panel No. 4 Firefighter Safety Task Group, as well as SEIA's PV Industry Forum. Since he can't post to the list, I am sharing his comments with the group: Drake, After reading your initial comments, I think you have nailed both the intent of this code section as well as the benefits. But in reading your second posting, I felt it important to write you. As one of the representatives from the Fire Service that drafted 690.12, I can tell you that while there is always room for improvement in language, the goal is to have PV that can not start a fire. As I am not a wrench I can not post to the list (feel free to share any of my comments here if you wish), but I would like to chime in on this conversation. Your assertion that ALECs are targeting the PV industry is not taking place in this process. There are many hard-working individuals from the PV industry, electrical inspectors, and the fire service working together to keep PV safe and secure for many years to come. I for one have both PV and thermal on my home. While you are correct that no fire fighter fatalities have resulted from a PV system shock, the goal is to prevent the first. One problem is that the PV industry has not adequately addressed the arc and ground fault problems in the US. Simply put, many rooftop systems are not NEC compliant; they can not detect and interrupt all faults. This has unfortunately resulted in far too many fires. The many additions changes to sec 690 in the 2014 cycle will go far in achieving a much safer system. The fire service is becoming increasingly aware, educated, and involved in the code process for PV safety. It should be clear that the goal for all parties is a safe electrical product. There is no secret agenda to pull the rug out from under solar. To those that are concerned with the imbedded cost increases, please take a longer view than your current FY. The systems that fire fighters respond to may be many years old, but in reality most of the fires have occurred on new systems. We will respond to older systems over time, and some buildings will be lost due to concern over the inability to isolate power down to a safe level. As I teach firefighters about electrical safety, many express both an interest in PV as well as concern that it should be possible to shut a system down in the event of an emergency either manually, or as a result of a fault. Thank you, Matt CA Matthew Paiss, E19B Bureau of Field Operations San Jose Fire Department 1661 Senter Rd San Jose, CA 95113 (831) 566-3057 c BTW: the stakeholders who developed the consensus language in 690.12 are listed in the NEC 2014 Report on Comments: This comment is the result of a consensus process established among three groups of stakeholders: 1) CMP4 Firefighter SafetyTask Group; 2) SEIA Codes and Standards Working Group; and 3) PV Industry Forum. Participants in these groups included the following individuals: CMP4 Firefighter Safety Task Group 1. Ward Bower, CMP4 representing SEIA 2. Bill Brooks, CMP4 representing SEIA and Chair of Task Group 3. Bob Davidson, Davidson Code Concepts 4. Mark Earley, Secretary, NFPA 5. Bob James, UL 6. Matt Paiss, City of San Jose Fire Department 7. Jim Rogers, CMP4 representing IAEI 8. Todd Stafford, CMP4 representing IBEW 9. Ronnie Toomer, Chair of CMP4 10. Peter Willse, Global Asset Protection Services SEIA Codes and Standards Working Group 1. Mark Albers, SunPower 2. Mark Baldassari, Enphase Energy 3. Ward Bower, SEIA 4. Bill Brooks, Brooks Engineering/SEIA 5. Joe Cain, Chair of SEIA Codes and Standards Working Group 6. Keith Davidson, SunTech 7. Darrel Higgs, Dow Solar 8. Lee Kraemer, First Solar 9. Carl Lenox, SunPower 10. Charles Luebke, Eaton 11. Martin Mesmer, E.ON 12. Steve Pisklak, Dow Solar13. Robert Rynar, First Solar 14. Michael Schenck, First Solar 15. John Smirnow, SEIA 16. Kris VanDerzee, First Solar 17. Leo Wu, SolarCity 18. Tilak Gopalarathnam, REFUsol Incorporated PV Industry Forum 1. Mark Albers, SunPower 2. Greg Ball, DNV 3. Bill Brooks, Brooks Engineering, lead for 690.12 4. Mark Baldassari, Enphase Energy 5. Ward Bower, SEIA 6. Michael Coddington, NREL 7. Marv Dargatz, SolarEdge 8. Chris Flueckiger. UL 9. Joerg Grosshennig, SMA 10. Darrel Higgs, Dow Solar 11. Dan Lepinski, Exeltech 12. Carl Lenox, SunPower 13. Charles Luebke, Eaton 14. Matt Paiss, City of San Jose Fire Department 15. Steve Pisklak, Dow Solar 16. Jim Rogers, Town of Oak Bluffs 17. Jon Sharp, Ampt 18. Bhima Sheridan, SolarCity 19. John Smirnow, SEIA 20. Holly Thomas, U.S. Dept. of Energy 21. Phil Undercuffler, Outback Power 22. John Wiles, NMSU, Secretary of PV Industry Forum 23. Leo Wu, SolarCity 24. Tim Zgonena, UL On Jan 24, 2014, at 1:00 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Drake drake.chamber...@redwoodalliance.org
Re: [RE-wrenches] RE-wrenches Digest, Vol 7, Issue 29
Drake, As far I know you are correct. There have not been any firefighter deaths due to solar. However, a fire chief in New Jersey did suggest that he let a warehouse burn down due to the presence of a PV system on the roof: http://www.myfoxphilly.com/story/23313172/multiple-alarm-fire http://www.theatlanticcities.com/technology/2013/09/why-firefighters-are-scared-solar-power/6854/ That suggests to me that while there is no crisis today, there is certainly the potential for one down the road. Imagine the insurance industry's response if fire fighters make a habit of not responding to structural fires due to the presence of PV systems. Fire fighters want touch-safe PV modules. And they have a reasonable complaint. They can safely shut down any electrical system in a building—except for PV systems. SEIA and SEPA are the solar industry lobby. Please do engage and support them. SEIA even has a political action committee, the SolarPAC. Part of the way that I try to stay on top of evolving Code issues is by attending SEIA- and SEPA-sponsored events. Also, over the past 4 or 5 years, the Solar America Board of Codes and Standards has scheduled annual meetings that coincide with Intersolar. Those are very informative sessions. I think the sessions are even archived online at solarancs.org. David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 On Jan 22, 2014, at 8:18 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Drake drake.chamber...@redwoodalliance.org Subject: Re: [RE-wrenches] NEC 2014 690.12 Rapid Shutdown Date: January 22, 2014 2:16:18 PM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org David, My sincere thanks to all of you who worked to keep the module level disconnect requirement out of the 2014 code cycle. That ruling would have amounted to a knockout punch for string and central inverters on buildings. What was the driving force behind this push for immediate module level disconnection? There has clearly not been a rash of firefighter deaths due to PV systems. Although PV needs to continue evolving safety standards that take into account the concerns of firefighters, there is no crisis that would justify thwarting one of the few growing sectors of our economy. The PV track record has been amazingly good. So far, I've found no accounts of solar related firefighter deaths or injuries. The NFPA statistics show that the highest cause of firefighter death is heart attack. http://www.nfpa.org/newsandpublications/nfpa-journal/2013/july-august-2013/features/firefighter-fatalities-in-the-united-states-2012 This push for crippling regulation bears the earmark of ALEC’s extensive and effective war on solar. As you can read in the following links, the massively funded, Koch brothers-linked ALEC is lobbying heavily, on every level, to derail solar. All who are associated with the solar industry need to be aware of this powerful lobbying campaign. http://www.theguardian.com/world/2013/dec/04/alec-freerider-homeowners-assault-clean-energy http://www.salon.com/2013/12/05/alec_freeriders_with_solar_panels_must_pay_for_robbing_the_system/ http://beforeitsnews.com/environment/2014/01/alec-gain-an-inside-track-on-colorado-solar-2490132.html Is there any way that the solar community can be alerted when threats to our industry are being put before the NEC? Although few contractors have the time or money to walk away from their businesses and attend code writing committees, a substantial number might have the time to make phone calls and send letters or emails to code writers. The solar industry needs a strong lobby of its own. Drake ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] NEC 2014 690.12 Rapid Shutdown
Drake, The language in 690.12 is the compromise solution that was reached to ensure continued industry stability. The alternative to the combiner-level shutdown was module-level shutdown. It took a consolidated industry effort to push the module-level requirements out one more Code cycle—for the exact reasons that you touch on below. Not sure if this link has been published on the Wrenches list or not, but it provides some background on the topic: http://www.youtube.com/watch?v=sUXShMZJorQ David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 On Jan 21, 2014, at 1:12 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: Drake drake.chamber...@redwoodalliance.org Subject: Re: [RE-wrenches] NEC 2014 690.12 Rapid Shutdown Date: January 21, 2014 11:36:15 AM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org Bill, It is good to see that energized conductors are going to be disconnected near the arrays. I've been an advocate of disconnecting these conductors by ground fault sensing equipment since ground fault detection was first implemented in the code. If contactors are to be installed on roofs, it likely won't be long before both ground faults and arc faults are automatically cleared. When the requirement for AC arc fault branch circuit protection was first put in the NEC, it was postdated to allow time for the electrical industry to adapt. This new remote disconnecting requirement does not provide any lead time. As the 2014 NEC is adopted in various jurisdictions, inspectors may feel that it is necessary to disallow systems without the newly required disconnect feature. This may result in serious problems for solar companies and customers, as well as manufacturers. The protection of firefighters is essential. The implementation of renewables is essential also. Insurance claims for weather related, global warming-triggered climatic disasters are rising exponentially. Extreme weather related events result in major loss of life and billions of dollars in property damage. Atmospheric CO2 levels continue to climb from the burning of fossil fuels. This is a crisis of global proportions. My request for code writers is to please take into account the effect that inserting new rules into the NEC may have on the stability of renewable energy, and implement new requirements in a way that will allow for a smooth interface. Thank you, Drake Drake Chamberlin Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified Solar PV 740-448-7328 http://athens-electric.com/ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] CA Fire code
Lars, Back in October, UL was in the process of finalizing a new fire test method for for roof-mounted PV systems. This new test method will bridge the gap between the fire tests for roofing coverings (UL 790) and those found in UL 1703, the standard for flat-plate PV modules. Long story short, Class C PV modules installed over a Class A roofing system will result in a Class A fire-rated roof-mounted PV system. At least that's how I understood the presentation delivered by Christopher Flueckinger from UL during the Fire Safety session at SPI in Chicago. I'm sure Bill Brooks will chime in shortly and provide more clarity. Best regards, David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] CA Fire code
With regards to the second part of your question, Trina has a glass-on-glass PV module: http://www.trinasolar.com/us/product/PDG5.html I suspect that the glass-on-glass module from SolarWorld is Class A fire rated as well. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] RE-wrenches Digest, Vol 6, Issue 423
William, Thanks for posting a link to that story. Here's more background on the tile roof integrated PV system recall and warranty fiasco: http://runonsun.com/~runons5/blogs/blog1.php/solworks/safety/suntech-recalls-solar-roofing-tiles http://runonsun.com/~runons5/blogs/blog1.php/ranting/centex-clouds-solar-tile-repairs http://runonsun.com/~runons5/blogs/blog1.php/solworks/safety/centex-suspends-solar-repairs http://runonsun.com/~runons5/blogs/blog1.php/solnews/centex-steps-up-will-replace It sounds like this could be a product design failure rather than a wire management issue. But wire management is certainly suspect until proven innocent. Regardless of the cause, since these are roof integrated systems, Centex basically needs to replace all of the TIPV systems with conventional rack-mounted PV systems—provided they can get the homeowners to sign the liability releases. Even though these are relatively unique installations, the general lessons would seem to apply broadly. Qualify your vendors carefully. Make sure your installers are properly trained. Put QC systems in place to catch problems. A small investment in quality wire management practices is cheap compared to the alternative. Best regards, David Brearley Senior Technical Editor, SolarPro magazine On Nov 11, 2013, at 1:02 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: From: William Miller will...@millersolar.com Subject: [RE-wrenches] House fire news Date: November 11, 2013 12:09:08 PM CST To: RE-wrenches re-wrenches@lists.re-wrenches.org Reply-To: RE-wrenches re-wrenches@lists.re-wrenches.org Friends: This was brought to my attention: http://on.aol.com/video/are-solar-panels-a-fire-hazard--518000682?hp=1playlist=127173icid=maing-grid7%7Cmain5%7Cdl12%7Csec1_lnk3%26pLid%3D403848 I know this is an isolated scenario, but bad PR can spread like umm, wildfire. We should all be aware of bad press so we can respond to questions about safety hazards. I think this story is relevant in that as the number of PV installations continues to grow, the chance of an accident naturally increases. I believe we all need to do the best work possible to minimize this risk. Even though some of the Code requirements seem illogical, I favor strict adherence to the code, including the more subjective judgments on good workmanship. I look forward to the day when plastic wire ties of any type are not accepted for wire management – I think they are sub-standard practice and increase the likelihood of fire or shock hazards. William Miller image003.jpg 17395 Oak Rd. Atascadero, CA 93422 www.millersolar.com 805-438-5600 voice ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Solar labels
I recently sat in on a free HellermannTyton webinar that included quite a bit of content related to solar labels: http://www.hellermanntyton.us/promo/webinar.aspx The webinar includes a good overview of NEC 2014 changes. It also emphasizes solar label solutions offered by HellermannTyton. And there are new labeling requirements on the way. If you're in the market for a new labeling solution, you might want to sign up for one of these webinars. There are 2 or 3 more scheduled in the near future. David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Cable tray
Not at all. Type USE cable was added to the Permitted Uses of Cable Tray, as outlined in Section 392.10(A) and the the companion Table 392.10(A). On Mar 26, 2013, at 10:02 AM, Glenn Burt wrote: Bill, Does this mean that USE-2 is not acceptable for use in this manner? Also, what is your confidence level that this will make it to the printer? I recall a few other instances of proposed amendments that at the last minute were not included in the past few code cycles (pertaining to PV). Too bad we are still on the 2008 code cycle here… Thanks Glenn Burt From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Brooks Sent: Monday, March 25, 2013 10:54 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] Cable tray All, Here is the language that has been accepted into the 2014 NEC: 690.31(C)(2) (2) Cable Trays. PV source circuits and PV output circuits using single-conductor cable listed and labeled as Photovoltaic (PV) wire of all sizes with or without a Cable Tray marking/rating shall be permitted in cable trays installed in outdoor locations provided the cables are supported at intervals not to exceed 30cm (12 in.) and secured at intervals not to exceed 1.4m (4.5’). I hope this helps. It is a very big deal. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, March 25, 2013 6:01 PM To: RE-wrenches Subject: Re: [RE-wrenches] Cable tray Ouch. I promise I'm not advocating for anything like that. What I may be missing is the Code reference that says no cable tray on roofs or similar. There is so much room for improvement in wire management practices, that being able to use cable tray seems like a step forward. I understand some jurisdictions do not allow it, but it appears as though Code changes were made specifically to address this. It's boring stuff, but you can read the explanation of the Code changes in the ROP and ROC documents. The Code changes a lot with regards to PV system, and Article 690 is more fluid than other articles. Some of this is the Code trying to keep up with technology. In other cases the Code evolves based on new applications for existing products. Often it changes because some areas of the Code are confusing for electricians and inspectors alike. If the new Code language is more clear in its intent than previous versions, some inspectors are willing to let installers build to the most current standard. That's all I'm advocating for: Trying to understand how the minimum requirements outlined in Code evolve over time so that you can have a friendly and informed conversation with your AHJ over a donut. On Mar 25, 2013, at 6:26 PM, William Miller wrote: David: This is great news. Now, whenever I want to do something that is prohibited by code, I can just say that the Code Making Panel is gonna correct that pesky code section (insert your problem citation here) any day now, so I might as well be allowed to do whatever it was I was fixin' to do anyway. Unless I am missing something... Thanks! William Miller PS: Just kidding. Hope no offense is taken. wm At 03:46 PM 3/25/2013, you wrote: So if you ever get called on 392.10(B)(2), I think you can point out that the Code Making Panels have been busy clarifying that cable tray is okay for source circuit conductors. Unless I'm missing something ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] diesel vs. solar
+1 for Maui Software. It is really helpful for finding the array-to-battery-to-generator capacity sweet spot. You can also use it to model things like the impact of various generator start/stop triggers. If you have monthly kWh meter readings for the site, you can build a daily average load profile on a month by month basis. (Better yet, monitor the daily load for a few weeks or months in the design season and use this as the basis for your model.) Then you can model system performance over a typical year and see when the generator is expected to run. The equipment library used to be pretty thin—and probably still is—but you can add equipment to the database. Or just model performance using similar equipment. When I used the software it didn't have the ability to model an AC coupled system. But for a typical DC coupled system, it will produce a lot of interesting/nerdy charts that will help designers anticipate high level performance trends for a proposed system. On Mar 25, 2013, at 10:18 AM, Ray Walters wrote: Also, Windy Dankoff's old spread sheet that I adapted calculates generator run time per week, and Maui SOlar software does a good job of calculating generator hours per year. I've used Homer and found it to be pretty far off from off grid reality. Any off grid application is going to benefit from inverters and batteries to keep the generator from having to run 24/7. Next, adding at least some PV to trickle charge the batteries is often a no brainer. . You definitely don't need as much battery in a hybrid system. Its not just a fuel issue, generator replacement and maintenance, along with more esoteric considerations like noise, and smell, need to be factored in as well. Figuring the ratio of generator run time vs. PV is a bit trickier, but I found you can sneak up on that calculation by starting with the generator, batteries, inverters, and smallish PV, then add more PV incrementally while monitoring gen run time. Real performance numbers always beat computer simulations, especially off grid, where it is often tough to characterize the real life complexity of the loads. There is a point if your baseline 24/7 loads are large enough, a full time generator makes sense, but unless its in Alaska, some PV almost always makes sense as well. Also the loads will determine how much design time to put in before hand. If your looking at a 50kw generator or up, you need to invest in some software and/ or get an off grid design specialist on board. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 3/25/2013 7:37 AM, Andrew Truitt wrote: Erika - HOMER (http://www.homerenergy.com/) is a hybrid power system modeling tool for on- or off-grid applications. There is a 2 week free trial period and then it costs $100 for a 6 month software license. I haven't used it yet but have heard good things. - Andrew Truitt Sent from my iPad On Mar 25, 2013, at 7:15 AM, Erika Weliczko er...@repowersolutions.com wrote: Does anyone know of an efficient calculator tool to help compare diesel /gas generator to PV + batt + small generator for an off-grid vacation house? Regards, Erika ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List
Re: [RE-wrenches] backup without batteries
SMA is hosting a webinar on this product line on April 2nd: http://www.sma-america.com/en_US/smasolaracademy/seminar-calendar/seminar-registration/seminars/sunny_boy_tl_us_series_eps_overview_live_webinar.html On Mar 25, 2013, at 11:11 AM, Bob-O Schultze wrote: Hiya Nick, SMA is bringing out an inverter that will do that. Not yet available, I think, but hopefully soon. I heard about it at the NABCEP CE conference this month in Sacramento, CA. I don't think it is specific to using the Mitsu PVs at all. Bob-O On Mar 25, 2013, at 8:56 AM, Nik Ponzio wrote: Forgive my senility. I recently read somewhere about development of grid-tie inverters without batteries that offer emergency power via a single 120V receptacle during grid outage (and sun.) Anyone seen anything on these? The brands mentioned were SMA Mitsubishi. Thanks in advance. -- Nicholas Ponzio Building Energy 1570 South Brownell Road Williston, VT 05495 802-859-3384 ext.15 (office) 802-658-3982 (fax) 802-318-4783 (cell) http://www.BuildingEnergyVT.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Cable tray
Uses permitted. 392.10(B)(1) requires that single conductor cable in cable tray be size 1/0 or larger. Here's the deal, though. NEC 2014 will add Service Entrance Cable: Types SE and USE to Table 392.10(A). It is not in that table now, which is why inspectors turn to 392.10(B). That means that under 390.10(A) in NEC 2014, Type USE conductor can be used in cable tray according to the methods outlined in Article 338. And references in 690.31 make it clear—if it isn't already— that PV Wire and USE-2 can generally be used interchangeably in PV systems, and that cable tray is accepted for source circuit conductors. So if you ever get called on 392.10(B)(2), I think you can point out that the Code Making Panels have been busy clarifying that cable tray is okay for source circuit conductors. Unless I'm missing something In Mar 25, 2013, at 5:17 PM, Chris Mason wrote: What part of 392 would be a problem? On Mon, Mar 25, 2013 at 6:12 PM, Glenn Burt glenn.b...@glbcc.com wrote: I think you will find it difficult to adhere to Article 392 and use a cable tray on a rooftop with source circuit conductors, if that is your hope. -Glenn From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Chris Mason Sent: Friday, March 22, 2013 3:08 PM To: RE-wrenches Subject: [RE-wrenches] Cable tray I'm looking for flat roof cable tray system that is cost effective. We previously used Cablofil and Cablo-port FSL 12 tray but it is very expensive for our current application due to the size of the roof. We need to install about 200' of tray and Cablofil galvanized is eating up the budget. Can anyone recommend a cheaper alternative. -- Chris Mason ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Chris Mason President, Comet Systems Ltd www.cometenergysystems.com Cell: 264.235.5670 Skype: netconcepts ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Cable tray
Ouch. I promise I'm not advocating for anything like that. What I may be missing is the Code reference that says no cable tray on roofs or similar. There is so much room for improvement in wire management practices, that being able to use cable tray seems like a step forward. I understand some jurisdictions do not allow it, but it appears as though Code changes were made specifically to address this. It's boring stuff, but you can read the explanation of the Code changes in the ROP and ROC documents. The Code changes a lot with regards to PV system, and Article 690 is more fluid than other articles. Some of this is the Code trying to keep up with technology. In other cases the Code evolves based on new applications for existing products. Often it changes because some areas of the Code are confusing for electricians and inspectors alike. If the new Code language is more clear in its intent than previous versions, some inspectors are willing to let installers build to the most current standard. That's all I'm advocating for: Trying to understand how the minimum requirements outlined in Code evolve over time so that you can have a friendly and informed conversation with your AHJ over a donut. On Mar 25, 2013, at 6:26 PM, William Miller wrote: David: This is great news. Now, whenever I want to do something that is prohibited by code, I can just say that the Code Making Panel is gonna correct that pesky code section (insert your problem citation here) any day now, so I might as well be allowed to do whatever it was I was fixin' to do anyway. Unless I am missing something... Thanks! William Miller PS: Just kidding. Hope no offense is taken. wm At 03:46 PM 3/25/2013, you wrote: So if you ever get called on 392.10(B)(2), I think you can point out that the Code Making Panels have been busy clarifying that cable tray is okay for source circuit conductors. Unless I'm missing something ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Cable tray
Thanks Bill. That's another welcome change to look forward to in NEC 2014. On Mar 25, 2013, at 9:53 PM, Bill Brooks wrote: All, Here is the language that has been accepted into the 2014 NEC: 690.31(C)(2) (2) Cable Trays. PV source circuits and PV output circuits using single-conductor cable listed and labeled as Photovoltaic (PV) wire of all sizes with or without a Cable Tray marking/rating shall be permitted in cable trays installed in outdoor locations provided the cables are supported at intervals not to exceed 30cm (12 in.) and secured at intervals not to exceed 1.4m (4.5’). I hope this helps. It is a very big deal. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, March 25, 2013 6:01 PM To: RE-wrenches Subject: Re: [RE-wrenches] Cable tray Ouch. I promise I'm not advocating for anything like that. What I may be missing is the Code reference that says no cable tray on roofs or similar. There is so much room for improvement in wire management practices, that being able to use cable tray seems like a step forward. I understand some jurisdictions do not allow it, but it appears as though Code changes were made specifically to address this. It's boring stuff, but you can read the explanation of the Code changes in the ROP and ROC documents. The Code changes a lot with regards to PV system, and Article 690 is more fluid than other articles. Some of this is the Code trying to keep up with technology. In other cases the Code evolves based on new applications for existing products. Often it changes because some areas of the Code are confusing for electricians and inspectors alike. If the new Code language is more clear in its intent than previous versions, some inspectors are willing to let installers build to the most current standard. That's all I'm advocating for: Trying to understand how the minimum requirements outlined in Code evolve over time so that you can have a friendly and informed conversation with your AHJ over a donut. On Mar 25, 2013, at 6:26 PM, William Miller wrote: David: This is great news. Now, whenever I want to do something that is prohibited by code, I can just say that the Code Making Panel is gonna correct that pesky code section (insert your problem citation here) any day now, so I might as well be allowed to do whatever it was I was fixin' to do anyway. Unless I am missing something... Thanks! William Miller PS: Just kidding. Hope no offense is taken. wm At 03:46 PM 3/25/2013, you wrote: So if you ever get called on 392.10(B)(2), I think you can point out that the Code Making Panels have been busy clarifying that cable tray is okay for source circuit conductors. Unless I'm missing something ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] P1 micro performance
The power quality should not be adversely affected. While I'm sure different manufacturers may limit power in different ways, in theory all the inverter is doing is moving the array off its MPP. Here's a description from AE: If the power available from the array exceeds the nameplate rating of the inverter, the inverter will limit the power and current coming from the array to the inverter’s maximum nameplate power and current rating. The inverter does this by reducing the DC input current, which causes the DC operating voltage to rise above the maximum power point of the array, thereby ‘clipping’ the array output. This effectively limits the output of the array without stressing the inverter. http://solarenergy.advanced-energy.com/upload/File/Application%20Notes/DCLoadingOfPVPinverters.55-600100-75-A.pdf On Mar 22, 2013, at 9:52 AM, William Dorsett wrote: OK, if the upper limit if the curve is “flat topped” do we get increased problems with harmonic noise at the knee as you would in modified “square” wave? Bill Dorsett Manhattan, KS From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Friday, March 22, 2013 8:43 AM To: RE-wrenches Subject: Re: [RE-wrenches] P1 micro performance Thanks for the clarification. FWIW: Flat topping is exactly what occurs. Inverter limiting clips the inverter output power curve (not the voltage or current wave forms). The chart below has one data point for every hour of the year. The clipped/flat-top area is the result of the 225 kW inverter limiting the power output of a 385 kW array: image001.jpg On Mar 22, 2013, at 1:07 AM, boB wrote: On 3/21/2013 9:59 PM, Exeltech wrote: Wrenches, I'm probably a lone voice on this .. and not intending to get overly picky. No, two lonely voices, Dan. I associate clipping with audio waveforms which stops the negative or positive voltage peaks flat. Also called flat-topping. Limiting is like turning down the volume. The waveform stays the same and does not distort as it would if it were being flat topped (and flat bottomed) Thanks ! boB Could we call power limiting what it is .. limiting, and not clipping? Clipping implies distortion, which isn't the case here. Limiting is just that. The inverter output is limited to some maximum value -- not clipped. The output power curve flattens when integrated over time, but this still isn't distortion in the waveform. It's simply a point in the output where the derivative is zero. Not increasing, not decreasing. Just .. zero. No additional increase in the output for an increase in available energy at the input. Think governor on an engine Thanks. Dan Lepinski, Sr. Engineer Exeltech / Exeltech Solar Products --- On Thu, 3/21/13, David Brearley david.brear...@solarprofessional.com wrote: From: David Brearley david.brear...@solarprofessional.com Subject: Re: [RE-wrenches] P1 micro performance To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Thursday, March 21, 2013, 11:37 PM Thanks for sharing the screen capture, Marco. Interesting issues to think about here. This is actually prime clipping season in many places (not sure about Hawaii) due to the cool weather. While there are more sun-hours in the summer, the cell temperatures are often high enough that you won't tend to see rated power out of the modules. While I'm not running performance models for work, the people who do are routinely increasing dc-to-ac ratios, often as high as 1.4-to-1. Having said that, most inverters aren't installed on a roof. (Not yet anyway.) I'd probably lean to a more conservative sizing ratio for micros. While I can imagine some scenarios where I'd be comfortable with a 215 W micro on a 265 W module—like a flat roof install in Vermont, which reportedly doesn't see 1,000 W/m^2 very often—I wouldn't try that here in Texas. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] P1 micro performance
Thanks for sharing the screen capture, Marco. Interesting issues to think about here. This is actually prime clipping season in many places (not sure about Hawaii) due to the cool weather. While there are more sun-hours in the summer, the cell temperatures are often high enough that you won't tend to see rated power out of the modules. While I'm not running performance models for work, the people who do are routinely increasing dc-to-ac ratios, often as high as 1.4-to-1. Having said that, most inverters aren't installed on a roof. (Not yet anyway.) I'd probably lean to a more conservative sizing ratio for micros. While I can imagine some scenarios where I'd be comfortable with a 215 W micro on a 265 W module—like a flat roof install in Vermont, which reportedly doesn't see 1,000 W/m^2 very often—I wouldn't try that here in Texas. On Mar 21, 2013, at 7:54 PM, Marco Mangelsdorf wrote: Check out the output of the modules below at 1PM on this Spring equinox for this system here in Hilo, Hawaii. These mods are SunPower 245s with the Power-One micro 250s. Notice that the AC outputs below are 223 watts and higher. If we had installed Enphase M215s instead, the max output possible would be ~ 224 watts. If there’s clipping this early in the year, imagine the degree to which the clipping will be increasing in the months to come as the solar insolation increases. And these mods were “only” 245s. Enphase states that their M215s are fine with modules up to 265 watts! Imagine the amount of clipping taking place when that kind of pairing takes place. marco image005.png image006.png ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Cracking Backing on Sharp NT-175U1 Modules
FWIW: I recently saw something similar at an installation in Central Texas that uses a similar product. The cracking in the weatherproof coating was highly localized, affecting ±8 out of ±48 modules. The affected modules differed from the others only in terms of the amount of reflected light incident on the back of the devices. (A shed roof installed over an ATV was reflecting sunlight up underneath a portion of a top of pole mounted array.) While the weatherproof material showed signs of accelerated aging—perhaps due to heat effects, reflected UV effects, or both—we could not measure any difference in performance using a multimeter. However, we did not have an I-V curve tracer with us and the irradiance was relatively low while we were at the site. On Feb 21, 2013, at 11:11 PM, Brian Sipp wrote: I inherited the service work on a couple of small commercial PV systems that were installed by another company about 7 years ago. The systems are Sharp NT-175U1 modules and Sharp JH3500U inverters. This client has been losing inverters at a rate of one or two per year for the last couple of years. When I was on-site yesterday, I noticed that the backing on all of the modules (there are 120 modules at this site) looks like it’s starting to shrink and crack all over. I’ve started an inquiry with Sharp but considering their level of response to the high number of inverter failures, I figured I’d come here before they get me doing diagnostic backflips. To be clear, this is the clear part of the backing I think Sharp is calling the “weatherproof coating.” It does not seem to have affected the white EVA part of the backing. However, the points in the EVA where these cracks run over the solder points between the cells seems to be very thin and I can see the dark color of the solder showing through more than elsewhere. By the time I got done with my testing on specific inverter problems and noticed the panels, I didn’t have any more time to do further testing for power output of the modules/strings so I don’t have any specific test results to share. My concern here is that this is the beginning of a bigger problem. Has anyone else had this experience? Brian Sipp First Source Solar www.FirstSourceSolar.com 530-554-1925 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] CIS mods
It is confusing that they refer to this as a light soaking effect. When we worked on this thin film article in SolarPro magazine a couple years ago, a researcher at NREL referred to this specific phenomenon as a dark soaking effect (see discussion under Performance Transients): http://solarprofessional.com/article/?file=SP4_1_pg34_Holz It is certainly possible for the Solar Frontier modules to have a better specific yield as compared to c-Si PV under certain environmental regimes. However, to suggest that this is always the case seems like overzealous marketing spin, which shouldn't really surprise anyone. There is a kernel of truth, but it is extrapolated ad absurdum. Bill Brooks likes to tell this joke/cautionary tale: You know how to tell when someone in marketing is lying? Their lips are moving. On Feb 18, 2013, at 6:25 PM, Kirpal Khalsa wrote: I don't understand the text as stated.I am not sure if they are simply referring to a common effect in most thin film panels where for the first few months they can output more than ratings, and then they settle down to what they are rated for, or if they are saying that after a few months the output will increase, once they are light soaked? -- Sunny Regards, Kirpal Khalsa NABCEP Certified Solar PV Installer Renewable Energy Systems www.oregonsolarworks.com On Mon, Feb 18, 2013 at 4:13 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: Yes, I saw that. Sounds like smoke and mirrors to me. marco On Mon, Feb 18, 2013 at 1:38 PM, Carl Emerson c...@solarking.net.nz wrote: Marco. Did you notice the claim in the text as follows… The Light Soaking Effect Following an initial period of exposure to sunlight, the CIS light soaking effect will result in higher output than factory spec. This has been proven by field data from around the world If correct this answers your question… Time will tell I guess. Regards Carl Emerson Aloha, Solar Frontier in Japan, the maker of copper-indium-selenium (CIS) mods, claims that their product produces more kWhs per kW installed than crystalline silicon. http://www.solar-frontier.com/eng/cis/index.html If you go to the Softbank Field Results on the right tabs area you can download a 4-page PDF report. I’m wondering if this is a hot-out-of-the-box phenomenon similar to some other non-cSi products and that after X months in the field the output stabilizes at a lower level. Anyone have any idea or experience with this? Thanks, marco ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Squirrel/leaf guard for solar array
Hi Carl, Check out the sidebar by Stephen Kane in this article for info on a couple squirrel guard product suppliers: http://solarprofessional.com/article/?file=SP6_2_pg30_Jacoby I do think that the same system can serve both purposes. Once the screen is in place it should be self-evident when the debris builds up and needs to be cleaned. When it's under the array, it's out of sight, out of mind and potentially a problem. Best, David On Feb 15, 2013, at 9:20 AM, Carl Adams wrote: Hello Wrenches, I serviced an array yesterday which had accumulated a large amount of leaves under the modules. No evidence of squirrels at this point, but I know there has been discussion of protective fencing around arrays to prevent squirrels moving in and I wonder if the same system might keep the leaf debri from building up under the array. Do any of you have suggestions for materials and methods to do this. A link to photos of installed projects would be appreciated. Thanks Carl Adams SunRock Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] high insolation value and inverter undersizing
I assume the device just operates the module away its MPP. That would reduce its power output. On Jan 29, 2013, at 8:48 AM, Larry Crutcher, Starlight Solar Power Systems wrote: Nick, You said the microinverter only draws enough current... Could you explain how this works? I primarily work with battery based systems and the charge controllers that perform current limiting do so by shunting the excess current as heat. How are you leaving current in the module? Thank you, Larry Crutcher Starlight Solar Power Systems On Jan 28, 2013, at 4:35 PM, Nick Soleil wrote: Hi John, It's important to clarify that the clipped power does not turn into heat within the microinverter. The microinverter only draws enough current to achieve it's max output rating, and the remaining current is left in the module, so to speak. So, the heat generated at peak times is the same, whether using a 260W module or a 280W module. Many string inverters actually work similarly. What's different for them, however, is their overall thermal situation. The primary thermal driver for a string inverter is the amount of heat generated by their electronics, and the ability of their fans fins to expel that heat. For example, a 5kW string inverter generates ~200W of heat at peak, and it has fans and fins sized accordingly. But, the effectiveness of the fans and fins depends on the ambient temperature (and on elevation/air mass), and if your inverter was operating at max power during hot weather (which would require significant oversizing due to the modules' temperature derates), it could exceed the capability of the fans and fins. This would then require the inverter to ramp-down output. (Actually, some string inverters can respond improperly--depending on whether their fan is continuous, load-controlled or thermally-controlled--and actually fry the electronics.) But, the thermal environment of a microinverter is very different. The main thermal driver in our situation is actually the external environment, not the electronics. Regardless of sizing ratio, an M215 generates less than 10 watts of heat at peak, whereas the heat radiated from the module at peak times will be substantially greater than that. Consequently, we've already over-engineered the microinverter for extreme heat management, and the thermal effects of sizing ratio are simply a drop in the bucket compared to the other factors. For that reason, we don't put limits in our warranty with regard to sizing ratio (which contrasts with at least some string inverter warranties), and we would not expect to see any microinverter ramp-down behaviors driven by sizing ratio. On Mon, Jan 28, 2013 at 11:06 AM, John Berdner john.berd...@solaredge.com wrote: Jason: Be careful of drawing false comparisons. There is no free lunch. Beyond the energy yield issues there are some reliability issues. You should also consider that running an inverter flat out all the time will shorten it’s life (due to the Arrhenius effect). http://en.wikipedia.org/wiki/Arrhenius_equation Think of the inverter temperature in the same way you would the power output curve (the two are closely related). Moving the whole power curve up “more on the shoulders” also moves the whole temperature curve up as well. The average lifetime (all this stuff is only probabilities) was projected with certain assumptions about how many hours at what temperature. As module sizes increase a given inverter will spend more time at a higher power level, i.e. runs hotter longer, which non-linearly reduces the life of the product. Just my $0.02… With the high labor cost of replacement it might be better to undersize the module relative to the power electronics or vice versa. This may or may not increase the installed system cost depending on the products you choose. Running everything flat out all the time is probably not the greatest idea. Best Regards, John Berdner General Manager, North America SolarEdge Technologies, Inc. 3347 Gateway Boulevard, Fremont CA 94538 USA (*Please note of our new address.) T: 510.498.3200, X 747 M: 530.277.4894 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Monday, January 28, 2013 5:30 AM To: RE-wrenches Subject: Re: [RE-wrenches] high insolation value and inverter undersizing I found the latest module rightsizing paper by Enphase pretty interesting. It does stand to reason that there are a lot of hours in the day where the inverter is producing less than rated power, so increasing the module size makes sense. Obviously there is an optimum point in every system where clipping exceeds gains, but that's virtually impossible to nail down due to so many factors being
Re: [RE-wrenches] Unisolar Intermittent Ground Fault
Let us know what the megohmmeter says. FWIW: There is some precedent for premature product failure in a roof-integrated product manufactured by Energy Conversion Devices (Uni-Solar): http://www.utsandiego.com/news/2012/sep/14/tp-flawed-solar-panels-removed-at-schools/?printpage=all On Nov 27, 2012, at 10:12 AM, Larry Crutcher, Starlight Solar Power Systems wrote: Robert, Having installed hundreds of Uni-Solar modules, the only failure I every experienced was a framed US64 that had the PV negative short to frame. Flexing the module would create intermittent failure. You have PV laminates so your ground fault may be to the metal roof. I might be stating the obvious but here's my list of tests: I would disconnect and hi-pot test each laminate (ref. sec. 4.6, pg 48, Installation Guide, AA4-3670-05, 10/05). If that does not produce results, apply pressure with a heavy roller up and down the edges where the diodes and cell interconnect traces are while testing. Check all wire penetrations into the channel. Make sure all wire expansion rules were followed, look for stressed wire. Check for any screws installed in other than the two approved areas. There are two versions of laminates. One has a VERY narrow area. 0.65 by 2.75, for screw penetration (ref. sec. 3, pg 17, Installation Guide, AA4-3670-05, 10/05). A misplaced screw may have allowed water to migrate to the trace areas and be providing a path through the screw. RIP Stan and Uni-Solar, A brilliant mind and the best performing PV's ever. Larry Crutcher Starlight Solar Power Systems On Nov 26, 2012, at 5:55 PM, Robert Nuese wrote: Dear Wrenches I've been experiencing a troubleshooting problem that you may be able to help me with. Or, can anyone refer me to someone, maybe an electrical engineer?, who I could hire to help. About 7 years ago I installed Unisolar modules on all the roofs of a complex of 12 mixed use buildings and one commercial building. These fed the grid through a variety of Fronius IG and SMA SunnyBoy inverters. Ever since, we have had occasional intermittent ground faults on a few of the roofs, and more frequent ones on one roof. At least some of these I suspect were caused by the roofer. Standard procedure on the Unisolar modules is to put two screws through them that hold on the roof ridge z-strip metal closure piece. These also keep the modules from sliding off the roof in extreme hot weather. I found a number of screws placed slightly outside the allowed screw zone. After I'd moved the screws (and removed the raised metal edges the screws had made in the roof, and put insulation between roof and module in those locations), this has seemed to fix some problems. Similarly, putting tefzel patches, per Uni- solar instructions, on some big dings and scratches may have fixed some others. However, I still occasionally, rather rarely, get ground fault indications on some inverters, and rather regularly get them on one specific IG 3000. Some times the indication is just in the software, and the problem disappears through resetting by disconnecting the inverter and reconnecting to reset the software. However, on that worst Fronius, it has usually blown the 1 amp ground fault fuse, indicating that there very likely has been a ground fault. I suspect that these ground faults are brought on by thermal expansion and contraction, that may only occasionally, and briefly, bring hot and ground elements of the system into close enough proximity. Dampness seems to play a part, the ground faults almost always occur during the rainy season, and usually during a rainy period. But whenever I get out to the site to test the system, the ground fault is always gone. I test by disconnecting both wires of each string, measuring the total voltage across, and then the voltage from each to ground. If there is a clear voltage to ground, then there is a ground fault, and its location in the string can be easily determined. If the voltage steadily goes toward zero, then a ground fault is not clearly present, and the location of where one had been is totally obscure. I've done very thorough visual inspection of the roofs, and also of the disconnects, junction boxes, and gutters that the wires pass through. As mentioned, the modules have had some problems, and I've fixed them all, as well as can be done. The wires all seem fine. Well connected, neat, not close to raw metal edges, insulation ok, etc. I've asked Unisolar (before they went bankrupt, now they don't answer the phones), and they've just recommended the testing I've done, and not had any other ideas. Same with Fronius - they think it's outside of the inverter, and the blown fuses support that position. I could go on with more details about what I've done and thought about, for instance, is the Fronius too sensitive? But I'll catch my breath and see if anyone else has some input
Re: [RE-wrenches] Unisolar Intermittent Ground Fault
Someone earlier suggested contacting Solmetric in Sebastapol: http://www.solmetric.com/contact-us.html Their PVA I-V curve tracer is a great troubleshooting tool, and they also carry a Megger MIT 430 insulation tester: http://www.solmetric.com/megger-mit430.html Maybe they have a kit (PVA + Megger) that they use in-house that you could rent you for a day? It's worth asking, especially since you are in the neighborhood. On Nov 27, 2012, at 5:32 PM, Robert Nuese wrote: Thanks to the Wrenches who have offered good advice. In answer to several of you who suggested megger testing, No, I'm afraid I don't own a megger. It had become clear to me that this might well be a useful tool in my case, but the things are expensive. I've managed to install pv systems for 10 years without one, so I can't justify buying one just for this one issue. I also had the impression that megger testing may be a bit hard to interpret, and perhaps incon- clusive, especially for someone with no previous experience. Now Larry Crutcher has drawn my attention to a Unisolar installation guide (newer than versions I've got) that gives instructions on how to use the megger to test a Unisolar installation. This is just what I need. I'm a bit surprised that the Unisolar techs I'd spoken to on several occasions about my problems had never talked about megger testing, or these instructions. So, I need a megger, at least temporarily. The Unisolar instructions call for the use of the BM21 or other quality megger. The BM21 is no longer in production. There are a confusing array of different models available. Can anyone offer suggestions about other models that would or would not be suitable for my use? According to the Megger co. website the new model that replaces the BM21 is the MIT525, which I can buy online for $3,576. Whew! On the other hand, I gather I can buy a Fluke 1507 insulation tester for $500. Would that be adequate? Anyway, even at that much cheaper, for solving one problem in 10 years, it would make more sense to rent… I called a few of the equipment rental agencies in my neighborhood, but none had ever heard of a megger. Does anyone have any idea where I could rent one - or is there a wrench in my neck of the woods (70 miles north of San Francisco) who would like to rent me theirs? Or does anybody have a suggestion about a particularly good deal on buying one? Or maybe there is a nearby wrench who I could hire to help, someone with a megger, who already knows how to use it.? Here is a big question. I had assumed that such testing would have to be done on de-energized circuits, which for the solar panel part would mean at night. The Unisolar instructions don't mention this. They say to disconnect each string and then short each out before the test, using a jumper. This strikes me as odd, and a bit scary. Would it not be better to do this on a de-energized circuit at night? Thanks very much for any further information, Robert Robert, Having installed hundreds of Uni-Solar modules, the only failure I every experienced was a framed US64 that had the PV negative short to frame. Flexing the module would create intermittent failure. You have PV laminates so your ground fault may be to the metal roof. I might be stating the obvious but here's my list of tests: I would disconnect and hi-pot test each laminate (ref. sec. 4.6, pg 48, Installation Guide, AA4-3670-05, 10/05). If that does not produce results, apply pressure with a heavy roller up and down the edges where the diodes and cell interconnect traces are while testing. Check all wire penetrations into the channel. Make sure all wire expansion rules were followed, look for stressed wire. Check for any screws installed in other than the two approved areas. There are two versions of laminates. One has a VERY narrow area. 0.65 by 2.75, for screw penetration (ref. sec. 3, pg 17, Installation Guide, AA4-3670-05, 10/05). A misplaced screw may have allowed water to migrate to the trace areas and be providing a path through the screw. RIP Stan and Uni-Solar, A brilliant mind and the best performing PV's ever. Larry Crutcher Starlight Solar Power Systems ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive:
Re: [RE-wrenches] EMT in attic
+1. John Wiles is awesome—and he would never mistake PV source or array circuits for a service. Not only are PV power circuits not a service, but PV systems (inverter output circuits) are not a service. The NEC defines all of this as power production equipment (705.2). By definition a service can only be provided by a serving utility (Article 100). That definition does not apply to PV systems. Having said that, Section 230.82(6) does allow PV systems to connect to the supply side of a service disconnect. But that allowance doesn't magically change the PV system into a service; it is still (parallel) power production equipment. If you're still in the planning phase, Nick, it is a good idea to see if they will allow you to use MC that complies with 250.118(10) according to 690.31(E) in NEC 2011. DCB On Nov 9, 2012, at 7:44 AM, Dave Click wrote: Nick, what the AHJ is telling you may actually be in reference to 250.97; for most PV output circuits (yes these are necessarily dc) this bonding requirement applies since array VOC 250 VDC. As Kent just pointed out, these dc conductors clearly don't meet the NEC definition of a service. 250.97 Bonding for Over 250 Volts. For circuits of over 250 volts to ground, the electrical continuity of metal raceways and cables with metal sheaths that contain any conductor other than service conductors shall be ensured by one or more of the methods specified for services in 250.92(B), except for (B)(1)... followed by an exception. Seems that FMC is OK as an EGC if your conductors have 20A OCPDs, which I imagine you do, but that FMC also can't be longer than 6' (see 250.118(5)). So I think your AHJ is probably right and I just learned something. If you're running a separate EGC anyway, you may want to ask why this bonding business is so important-- but I don't have an NEC reference on this to help you argue this. Maybe the AHJ would allow you to just run MC cable as the 2011 NEC allows. John Wiles is awesome. Someone on this list had to say it. DKC On 2012/11/8 23:22, Nick Vida wrote: Hi Wrenches, Thanks for you comments. Fun for the day is hearing they want to apply section 230 about service conductors and say that flex is not a metallic raceway because it is no good for bonding. They are defining the pv source circuits as a service. I am getting a distinct Wiles vibe here. I find it so annoying when they try to put out these distinctions with no code, no city ordinance and not even an internal memo, especially when they remain obstinate without going to the trouble to actually legitimize the interpretation. Dan- are the output circuits necessarily DC? I would have to look at NEC for a minute, but it doesn't seem to add up to me right now. Thanks, Nick Vida ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] EMT in attic
FWIW: In the 2011 Code, Section 690.31(D) is changed to include the following: Where dc photovoltaic source or output circuits…are run inside a building or restructure, they shall be contained in metal raceways,Type MC metal-clad cable that complies with 250.118(10), or metal enclosures… On Nov 3, 2012, at 10:41 AM, Nick Vida wrote: Hello wrenches, wondering if any of you are running into inspectors wanting EMT in the attics, or allowing flex only if there is a fusible disconnect on the roof. We have heard this a few time lately and havent yet seen a code reference, (except 690.31e saying metal raceways are fine- not specifying EMT only). I am wondering if this is a new wave of inspectors wanting the future now as informed by an expert seminar, or if there is something I am not aware of. Any comments are very appreciated. Thank you, Nick Vida wrench ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] EMT in attic
Sorry, per the OP this appears in 690.31(E)... On Nov 3, 2012, at 11:19 AM, David Brearley wrote: FWIW: In the 2011 Code, Section 690.31(D) is changed to include the following: Where dc photovoltaic source or output circuits…are run inside a building or restructure, they shall be contained in metal raceways,Type MC metal-clad cable that complies with 250.118(10), or metal enclosures… On Nov 3, 2012, at 10:41 AM, Nick Vida wrote: Hello wrenches, wondering if any of you are running into inspectors wanting EMT in the attics, or allowing flex only if there is a fusible disconnect on the roof. We have heard this a few time lately and havent yet seen a code reference, (except 690.31e saying metal raceways are fine- not specifying EMT only). I am wondering if this is a new wave of inspectors wanting the future now as informed by an expert seminar, or if there is something I am not aware of. Any comments are very appreciated. Thank you, Nick Vida wrench ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Two NEC questions
RE Question #2: Article 100 defines a service as: Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served. (emphasis added) PV system wiring simply does not fit that definition. The PV system is not part of the serving utility. And inverters are not service equipment. You need to refers them to this definition in Article 705.2 (added in NEC 2011): Power Production Equipment. The generating source, and all distribution equipment associated with it, that generates electricity from a source other than a utility supplied service. (emphasis added) FWIW: Mike Holt has written for SP about the Code requirements for interconnecting PV systems, as well as some additional recommendations for making supply side connections: http://solarprofessional.com/article/?file=SP5_1_pg14_QAsearch= RE Question #1: I had a local inspector ask me about this in late-August there were relatively few listed products at that time: SMA America has dc AFCI in their standard SunnyBoy US-series inverters (SB 3000-US, SB 3800-US, SB 4000-US, SB 5000-US, SB 6000-US, SB7000-US, SB 8000-US): http://www.sma-america.com/en_US/news-information/current-news/news/news/1487.html Microinverter systems (Enphase, Enecsys, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11 AC module systems (powered by SolarBridge, Exeltech, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11 SolarBOS reportedly has a dc AFDI and GFI combiner box: http://www.solarbos.com/news/solarbos-puts-out-the-fire-in-pv-systems (However, I don't see this product on their website under their regular lists of products.) While module-level dc-to-dc converters—like those from SolarEdge and Tigo Energy—presumably have the ability to provide dc AFCI capabilities, last I checked it didn't look like any of them were formally listed to do so. I suspect that most manufacturers are trying to avoid spending additional money on testing until the market requires this. Have any wrenches here actually had an inspector required dc AFCI? Also, is the dc AFCI test standard actually finalized and adopted at this point or are companies testing to a draft standard? David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Oct 13, 2012, at 10:12 AM, Rebecca Lundberg wrote: Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Utility disconnect
If this is simply a Code consideration, then the NEC does not require a visible/lockable disconnect. You can refer to this SolarABCs document for a thorough discussion of the subject: http://www.solarabcs.org/about/publications/reports/ued/pdfs/ABCS-05_studyreport.pdf On Oct 2, 2012, at 5:21 PM, Jesse Dahl wrote: I just finished a job on a home where the utility didn't require the utility disco. They contend that the service disconnect on the farmer panel meter base will work for them. I said cool and didn't put one in. The inspector said he couldn't sticker the project because the utility disco was missing. I asked to see where that disconnect is required by code and he said he would get back to me and drove off. Anyone come across this? Jesse Sent from my iPhone ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Enphase M210
Jason, You might also check out SunPower's ac modules: http://us.sunpowercorp.com/homes/products-services/solar-panels/AC-home-solar-panel/ On Sep 26, 2012, at 5:49 PM, Sequoya Cross wrote: I haven’t seen a full compatibility list on the new SMA-240US. At this point technical downloads aren’t available and the data that is present on the website is still preliminary. I do have a contact who is beta-testing the units and will see if he has any more information or wants to comment. Thanks- Sequoya Cross Backwoods Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Tuesday, September 25, 2012 4:50 AM To: RE-wrenches Subject: Re: [RE-wrenches] Enphase M210 Uh oh I guess that means no more SunPower E18/230 with Enphase. That sucks - it was a good premium product offering for us. Anyone know if the SMA or other microinverters are compatible with SunPower? Jason Szumlanski Fafco Solar On Mon, Sep 24, 2012 at 6:51 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: Uh oh….I just learned that our Enphase friends are no longer making the M210s. I need (50) of ‘em @ 240V. Anyone have any leads on that many, please? Please contact me off-list. Thanks, marco ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] posting request
Steve, Have you checked out SolarNexus? http://www.solarnexus.com/ As I understand it, their goal is to provide all of the functionality you describe in a single platform. Best regards, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Sep 17, 2012, at 12:08 PM, Steve McCarney wrote: Dear Wrenches Can anyone recommend a software package that is good for solar electric project management? We would like to be able to have the capability to coordinate scheduling, procurement, budgeting, expense tracking as well as noting communications about a given project. If an integrated package doing all these things doesn’t exist we’re especially interested in just good stand-alone procurement software that takes projects from BOM, to request for bids, to POs and invoices. Thanks. Steve McCarney, Project Manager Solar Electric Light Fund ___ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ballasted Roof Racking Recommendations?
Here's a link: http://us.sunpowercorp.com/commercial/products-services/rooftop-solar-systems/T5/ On Aug 31, 2012, at 11:13 PM, benn kilburn wrote: Ray, Are those the BIPV ones? Can you provide a model or a link? Thanks, Benn DayStar Renewable Energy Inc. www.daystarsolar.ca * Ph: 780-906-7807 Construction Electrician Solar Photovoltaic Systems Certified Certificate # 0007S HAVE A SUNNY DAY On 31/08/12 9:43 PM, R Ray Walters r...@solarray.com wrote: Sunpower has just that. Very easy install, no grounding issues, super high efficiency. Downsides: expensive, Plastic, finicky layouts from their engineers that preclude using it on smaller roofs. I would use it again for a larger roof that needed to max out the output/ sq ft of roof. It's probably the best commercially available module in the world, definitely the most efficient. Last I checked it qualified as American made, though some of it is made in indonesia I believe. Ray Walters ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Up for a 1-Line Riddle?
I'm assuming it's a balanced 3-phase interconnection, which fits with the reported phase current of 42 A: (3 x 5000 W) / 208 V / 1.73 = 41.7 A Or more simply: 24 A per inverter x 1.73 = 41.5 A However, no one reviewing a single-line should have to guess about the service type On Aug 30, 2012, at 3:12 PM, Dave Click wrote: I've seen that one a lot, too. And not to quibble, but the 1-line depicts this correctly (no inline fuse shown in the inverter DC disconnect box), though there should be a note making this more explicit. Speaking of sunny days turning off the system, how about the 3 30A inverter breakers' combined feed going into a 55A breaker. Also... a 55A breaker? Really? I guess the designer wanted to leave a little headroom to avoid scaring the 60A disconnect. DKC On 2012/8/30 14:35, Andrew Truitt wrote: Ahh yes, the old combine strings before landing on a fused DC input terminal trick. Sure to blow the fuse the first sunny day. This is why SMA created their fuse-bypass DC input terminal. I take it the installer was not aware of this... For a brighter energy future, Andrew Truitt NABCEP Certified PV Installer™ (ID# 032407-66) Principal Truitt Renewable Energy Consulting (202) 486-7507 tel:%28202%29%20486-7507 http://www.linkedin.com/pub/andrew-truitt/8/622/713 Don't get me wrong: I love nuclear energy! It's just that I prefer fusion to fission. And it just so happens that there's an enormous fusion reactor safely banked a few million miles from us. It delivers more than we could ever use in just about 8 minutes. And it's wireless! ~William McDonough On Thu, Aug 30, 2012 at 11:53 AM, Jason Szumlanski ja...@fafcosolar.com mailto:ja...@fafcosolar.com wrote: I was sent to look at another contractor's work, and found three SB5000 inverters with blown string input fuses. I was able to determine the reason pretty quickly, and was later sent the original 1-Line, which was installed per the drawings. The 1-Line came from a leading system integrator who shall remain nameless. See anything wrong? https://www.sugarsync.com/pf/D6539806_8669786_010829 Just goes to show you - the contractor needs to take responsibility and verify the specifications are correct, safe, and code compliant. Jason Szumlanski Fafco Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org mailto:RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ilsco SGB bonding lug
Some of the aluminum lugs are indoor-rated. They have a set screw will rust in an outdoor environment. That's one of the classic John Wiles slides. I'd just watch out for that On Aug 27, 2012, at 3:04 PM, Jay Peltz wrote: Hi Brian Isn't another way to go: Use the AL lugs and AL grounding wire? Jay Peltz power Sent from my iPhone On Aug 27, 2012, at 12:53 PM, Brian Mehalic br...@solarenergy.org wrote: I believe the UL467 listing means that it is rated for direct burial/outdoor use. Brian Mehalic NABCEP Certified Solar PV Installer™ R031508-59 IREC ISPQ Certified Affiliated Instructor/PV US-0132 PV Curriculum Developer and Instructor Solar Energy International http://www.solarenergy.org .org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ilsco SGB bonding lug
Yes, sorry. I wasn't speaking of this lug...I like the redesign. Looks quicker and easier and robust. On Aug 27, 2012, at 3:17 PM, Jason Szumlanski wrote: Yeah, but this one is marketed as a solar bonding lug. I think it's safe to say that it appropriately rated for outdoor use. It's always good to double-check, of course. Jason Szumlanski Fafco Solar On Mon, Aug 27, 2012 at 4:11 PM, David Brearley david.brear...@solarprofessional.com wrote: Some of the aluminum lugs are indoor-rated. They have a set screw will rust in an outdoor environment. That's one of the classic John Wiles slides. I'd just watch out for that On Aug 27, 2012, at 12:53 PM, Brian Mehalic br...@solarenergy.org wrote: I believe the UL467 listing means that it is rated for direct burial/outdoor use. Brian Mehalic NABCEP Certified Solar PV Installer™ R031508-59 IREC ISPQ Certified Affiliated Instructor/PV US-0132 PV Curriculum Developer and Instructor Solar Energy International http://www.solarenergy.org .org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Fronius replacement
Off the top of my head...Power-One? You can download an Excel file with comprehensive string inverter specs here: http://solarprofessional.com/webexclusive/ On Aug 27, 2012, at 4:06 PM, William Miller wrote: Friends: We have a client that wants to divest of 8 Fronius LG-4500 LV inverters. They are experiencing a high number of failures. The Fronius have an unusually low DC input window: 150 to 450 VDC. This means the stringing will result in a lower voltages than typically found and makes it difficult to substitute inverters. Does anyone know of any reliable inverter that will work with string voltages in the low 200s? Thanks in advance. William Miller Miller Solar Voice :805-438-5600 email: will...@millersolar.com http://millersolar.com License No. C-10-773985 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Ilsco SGB bonding lug
Yep. Definitely lower cost that tin-plated copper. Designed with PV frame grounding in mind. Lots to like On Aug 27, 2012, at 7:59 PM, Brian Mehalic wrote: I think the tin plating is to minimize/eliminate galvanic corrosion. Tim plated aluminum - now that sounds smart! Typos courtesy of my iPhone. On Aug 27, 2012, at 8:52 PM, benn kilburn b...@daystarsolar.ca wrote: Kirpal. The Ilsco lug GBL-4 also comes with a stainless steel set-screw… as stated here….GBL LAY-IN AL/CU if that is all it takes to use the AL lug outdoors (stainless steel set-screw), then why have we been steered towards the 'direct burial rated' tin-plated copper lug instead of an AL lug with SS set-screw? I'm not trying to make a case to not use the SGB lug, I like it and would like to keep some in stock, as they seem pretty useful, I just want to have my bases covered if/when an inspector questions me on them being approved for the application. Dan, Agreed! Been trying to get an answer from Ilsco, just tracking down the right person with the answers. Cheers, benn DayStar Renewable Energy Inc. www.daystarsolar.ca * Ph: 780-906-7807 Construction Electrician Solar Photovoltaic Systems Certified Certificate # 0007S HAVE A SUNNY DAY On 27/08/12 5:42 PM, Kirpal Khalsa solarwo...@gmail.com wrote: Benn...it looks like that lug has stainless hardware for corrosion resistance as stated on the brochureThat would be the biggest consideration as David Brearly mentioned earlier in regards to rust potential. Stainless hardware and tin plating is equivalent to the WEEB lugsTin plating and stainless hardware is as good as anything else available as far as outdoor ratings are concerned. I see your point that it is not explicitly stated for outdoor usehowever being marketed for use with solar panels also seems to imply rather obviously that it is outdoor rated.in my unofficial opinion. -- Sunny Regards, Kirpal Khalsa NABCEP Certified Solar PV Installer On Mon, Aug 27, 2012 at 4:11 PM, benn kilburn b...@daystarsolar.ca wrote: Thanks for the feedback Wrenches, lots of interesting comments, However I'm still wondering….. How does one confirm that it is specifically approved for outdoor use? Other than assuming it is implied (because it is 'marketed' as a solar lug). As far as I can tell UL 467 does not imply outdoor rated as the aluminum lug GBL-4 is also UL467 listed. See here…GBL LAY-IN AL/CU. As well, and as Gary pointed out with his second link, for a module bonding/grounding method to be acceptable, it must be recognized by the module manufacturer, no? Which means that any new bonding product on the market must have the blessing of each mod mfgr. (by way of letter or mention in its install manual). I have come across inspectors that actually look for this. Jason, you wrote I like the looks of that lug. However, I've been using WEEBs too long to go back now. I agree, and i'm not looking to replace weebs with these, but these certainly seem to have a place in the What do you use for the bonding connection from the ?rails? This SGB lug was suggested for this purpose as well. Benn DayStar Renewable Energy Inc. www.daystarsolar.ca * Ph: 780-906-7807 Construction Electrician Solar Photovoltaic Systems Certified Certificate # 0007S HAVE A SUNNY DAY On 27/08/12 2:35 PM, Gary Willett g...@icarussolarservices.com wrote: Here's the Ilsco listing from UL, where it's classed as Grounding and Bonding Equipment: http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=KDER.E34440ccnshorttitle=Grounding+and+Bonding+Equipmentobjid=1074099002cfgid=1073741824version=versionlessparent_id=1073988940sequence=1 The GuideInfo for Grounding Bonding Equipment lists: Grounding and Bonding for Photovoltaic (PV) Systems — Grounding and bonding equipment intended for use in PV systems are additionally investigated in combination with the PV module/panel (see QIGU) to the applicable requirements for such products. Installation instructions provided with the PV system (see QIGU) identify the specific grounding and bonding device that has been investigated and intended for use with that system. http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=KDER.GuideInfoccnshorttitle=Grounding+and+Bonding+Equipmentobjid=1074098839cfgid=1073741824version=versionlessparent_id=1073988940sequence=1 Regards, Gary Willett, PE On 8/27/2012 3:20 PM, David Brearley wrote: Yes, sorry. I wasn't speaking of this lug...I like the redesign. Looks quicker and easier and robust. On Aug 27, 2012, at 3:17 PM, Jason Szumlanski wrote: Yeah, but this one is marketed as a solar bonding lug. I think it's safe to say that it appropriately rated for outdoor use. It's always good to double-check, of course. Jason Szumlanski Fafco Solar
Re: [RE-wrenches] L feet no flashing in shingle roof
Todd, The issue isn't whether your approach works, but whether it is defensible in the event that something leaks. Most solar contractors receive public funds (rebate monies, ARRA program distributions, etc.). Some of those companies are installing systems in a manner that is not building code compliant. It just takes a high profile leaky roof at a VA hospital or a public housing project where a solar system was installed in a manner that does not meet the building code to lose years of goodwill and support for the industry. Modules prices have fallen quite a bit, but we all loose if State and Federal or public (opinion) support for the industry goes away. Obviously, that's the worst case scenario: That somehow the industry gets painted as being made up of a bunch of irresponsible, fly-by-night, subsidy chasers. Probably nothing to worry about, though. I'm pretty sure there's no precedence for that sort of thing actually happening. Right? What's more likely is that AHJs will get hip to the fact that they need to inspect the building code compliance of roof attachments. When they do, which side of the curve will your company be on? (Since your mind seems to be made up, Todd, that question is addressed to List at large.) Happy Independence Day, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Jul 3, 2012, at 10:37 PM, toddc...@finestplanet.com wrote: i wasn't going to enter into this discussion, but this posting prompted me. my most recent job was done with the assistance of the customer. he and i have a long working history, my being his employee some 25 years ago installing shw systems in the area, and now he hiring me to do his personal home's pv system. he insisted on straight L foot mounting without flashings... and i have to agree. in the 25 to 30 years since we did those shw systems, not a single one has leaked. plus, the installation was at the roof ridgeline, so pv quick mounts wouldn't have worked anyway. we put 2 X 8 blocking in the attic between the trusses to acomodate the mounting bolts and used a nice fattie gob of black silicone on each foot, which gooshed out when tightened. the mount will easily outlast the roof... leak free. honestly, i don't care what the ubc/ibs says. if done properly, these kinds of mounts are bombproof. years of experience backs this up. also, i have seen plenty of 'code compliant' oatey no-caulk sewer vent flashings with rotten rubber leaking into homes to know flashed penetrations are no panacea either. todd On Tuesday, July 3, 2012 2:53pm, David Brearley david.brear...@solarprofessional.com said: +1 on the use of structural screws. We ran an article about lag screws a couple years ago: http://solarprofessional.com/article/?file=SP3_4_pg70_Shelly One of the things that surprised me when I read this manuscript is how variable lag screws are in terms of construction and quality. Besides the convenience of being able to drive a structural screw without a pilot hole, the engineering specs are likely better documented and the manufacturing tolerances are probably tighter as well. FWIW: I think that using unflashed attachments in these litigious times is unwise. It's not consistent with best practices in the construction industry. It does not meet building codes. It violates the roof warranty. It makes your competition look good. We ran our first article on this topic 4 years ago, in our inaugural issue of SolarPro magazine: http://solarprofessional.com/article/?file=SP1_1_pg72_Fain The industry has come a long way since then, both in terms of awareness and in terms of off-the-shelf flashed attachment options. There are so many quality flashed attachment solutions to chose from now that I'm not sure why anyone would knowingly expose themselves to a possible construction negligence claim. Drive straight, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Jul 3, 2012, at 4:11 PM, Garrison Riegel wrote: The EcoFasten GF1 flashing is easy to install on a retrofit and will not necessarily add any height to the rail. If you do need to trim the flashings installed around the skylight, then I would recommend adding sealant to these penetrations. We ditch the included lag and use a 5/16” GRK RSS (self tapping structural screw). The combination works great and does not require a pilot hole. RSS: http://www.grkfasteners.com/en/RSS_1_2_information.htm GF1 http://ecofastensolar.com/pdf/GF1%20Cutsheets.pdf Best, Garrison Riegel Project Manager Solar Service Inc [p] 847-677-0950 [f] 847-647-9360 www.solarserviceinc.com NABCEP Certified Solar PV and Thermal Installer™ “There is no room
Re: [RE-wrenches] L feet no flashing in shingle roof
In some cases, you can install blocking to get up on the ridge consistently. One alternative to hangar bolts is to use corrugated mounting bridges from DPW Solar or something similar from another company. Sorry I can't link to the PDF. Google: corrugated mounting bridges Since exposed-fastener metal roofs already have a bunch of holes in them, you're not voiding the roof warranty by punching more holes in the ridge. (I don't think these roofs even meet the NRCA definition of a roof assembly because of the exposed penetrations.) Penetrations in the valleys on a roof are problematic for obvious reasons. On Jul 4, 2012, at 6:01 AM, Chris Mason wrote: All of this refers to shingle roofs, which we don't see much of. We mostly deal with concrete and corrugated steel/galvalume, the latter being a nightmare. Does anyone have good ideas for dealing with corrugated? There's no way to flash it, the blocks are fine when you hit a beam on the ridge but half the time your penetration has to be on the trough of the corrugated steel. Other than lots of goop, I don't know how else to seal it. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] L feet no flashing in shingle roof
Presumably most solar contractors benefit from increased sales due to the availability of a 30% federal tax credit. Arguably, that's not the same thing as receiving public funds, but the net effect is the same. My point is simply that as an industry we are dependent upon public support and a variety direct and indirect subsidies. That raises questions about accountability, about how those funds are being spent. The best thing that we can do as an industry is strive to adopt best practices that are beyond reproach, equivalent standards for other trades, and ideally defensible in a court of law in the event that things go south for whatever reason. (Forget the bureaucrats in the city, it's the lawyers who capitalize on construction negligence claims. The last one on the roof is the first one blamed. Often, we're the last ones on the roof.) On Jul 4, 2012, at 10:31 AM, m...@hurshtown.com m...@hurshtown.com wrote: Most solar contractors receive public funds I'll have to take issue with that one. I know of no such contractors in my part of the US. The issue isn't whether your approach works, but whether it is defensible in the event that something leaks. Our redneck methods may not satisfy the big city folks, but no failures in 20 years means more to our customers than satisfying some bureaucrat's requirements. ___ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] L feet no flashing in shingle roof
Bill, FWIW: none of the companies with flashed attachments solutions mentioned in the article we ran in SP1.1 were advertisers. Having said that, I do see a lot of articles in trade publications that are pretty shameless exercises in product placement. I've always found that off-putting and assumed that others feel the same way. That's why we try to develop content that does not insult our readers. Rather running a pay-to-play kind of shop, our goal has always been to publish the best technical content possible. If readers like the content, then we get more industry subscribers. Reaching that audience is desirable to advertisers. Having advertiser support allows us to compensate authors for their high quality technical content that readers enjoy. Ideally, it's a win-win-win situation. Let me know if there's something you think we could be doing better. Thanks, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Jul 4, 2012, at 2:25 PM, Bill Loesch wrote: David, Why does your editor put Todd's articles (and use him as a cover story) in your magazines (more than once, I believe) if it is not for his _experience_? The fact that there is a prescribed product (more than one in this case) that gets blessed when old fashioned, time tested, craftsmanship has already solved the problem is a testament to what payola will buy. No leak, no negligence, no claim. But then your magazines wouldn't garner such a big advertizing budget without all those manufacturers with new and improved products. Additionally, this List would perhaps have to find alternative funding, too. If you are really interested in eliminating the irresponsible, fly-by-night, subsidy chasers one easy way may be to eliminate the subsidy. Bill Loesch Solar 1 - Saint Louis Solar On 04-Jul-12 10:07 AM, David Brearley wrote: Todd, The issue isn't whether your approach works, but whether it is defensible in the event that something leaks. Most solar contractors receive public funds (rebate monies, ARRA program distributions, etc.). Some of those companies are installing systems in a manner that is not building code compliant. It just takes a high profile leaky roof at a VA hospital or a public housing project where a solar system was installed in a manner that does not meet the building code to lose years of goodwill and support for the industry. Modules prices have fallen quite a bit, but we all loose if State and Federal or public (opinion) support for the industry goes away. Obviously, that's the worst case scenario: That somehow the industry gets painted as being made up of a bunch of irresponsible, fly-by-night, subsidy chasers. Probably nothing to worry about, though. I'm pretty sure there's no precedence for that sort of thing actually happening. Right? What's more likely is that AHJs will get hip to the fact that they need to inspect the building code compliance of roof attachments. When they do, which side of the curve will your company be on? (Since your mind seems to be made up, Todd, that question is addressed to List at large.) Happy Independence Day, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Jul 3, 2012, at 10:37 PM, toddc...@finestplanet.com wrote: i wasn't going to enter into this discussion, but this posting prompted me. my most recent job was done with the assistance of the customer. he and i have a long working history, my being his employee some 25 years ago installing shw systems in the area, and now he hiring me to do his personal home's pv system. he insisted on straight L foot mounting without flashings... and i have to agree. in the 25 to 30 years since we did those shw systems, not a single one has leaked. plus, the installation was at the roof ridgeline, so pv quick mounts wouldn't have worked anyway. we put 2 X 8 blocking in the attic between the trusses to acomodate the mounting bolts and used a nice fattie gob of black silicone on each foot, which gooshed out when tightened. the mount will easily outlast the roof... leak free. honestly, i don't care what the ubc/ibs says. if done properly, these kinds of mounts are bombproof. years of experience backs this up. also, i have seen plenty of 'code compliant' oatey no-caulk sewer vent flashings with rotten rubber leaking into homes to know flashed penetrations are no panacea either. todd On Tuesday, July 3, 2012 2:53pm, David Brearley david.brear...@solarprofessional.com said: +1 on the use of structural screws. We ran an article about lag screws a couple years ago: http://solarprofessional.com/article/?file=SP3_4_pg70_Shelly One of the things that surprised me when I read
Re: [RE-wrenches] L feet no flashing in shingle roof
+1 on the use of structural screws. We ran an article about lag screws a couple years ago: http://solarprofessional.com/article/?file=SP3_4_pg70_Shelly One of the things that surprised me when I read this manuscript is how variable lag screws are in terms of construction and quality. Besides the convenience of being able to drive a structural screw without a pilot hole, the engineering specs are likely better documented and the manufacturing tolerances are probably tighter as well. FWIW: I think that using unflashed attachments in these litigious times is unwise. It's not consistent with best practices in the construction industry. It does not meet building codes. It violates the roof warranty. It makes your competition look good. We ran our first article on this topic 4 years ago, in our inaugural issue of SolarPro magazine: http://solarprofessional.com/article/?file=SP1_1_pg72_Fain The industry has come a long way since then, both in terms of awareness and in terms of off-the-shelf flashed attachment options. There are so many quality flashed attachment solutions to chose from now that I'm not sure why anyone would knowingly expose themselves to a possible construction negligence claim. Drive straight, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Jul 3, 2012, at 4:11 PM, Garrison Riegel wrote: The EcoFasten GF1 flashing is easy to install on a retrofit and will not necessarily add any height to the rail. If you do need to trim the flashings installed around the skylight, then I would recommend adding sealant to these penetrations. We ditch the included lag and use a 5/16” GRK RSS (self tapping structural screw). The combination works great and does not require a pilot hole. RSS: http://www.grkfasteners.com/en/RSS_1_2_information.htm GF1 http://ecofastensolar.com/pdf/GF1%20Cutsheets.pdf Best, Garrison Riegel Project Manager Solar Service Inc [p] 847-677-0950 [f] 847-647-9360 www.solarserviceinc.com NABCEP Certified Solar PV and Thermal Installer™ “There is no room for flashings. The L feet will go very close to the skylights and the flashing would hit the edge of them. Plus there is an existing array that was done by another installer that is done with L feet only. The new array would be higher.” ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] NABCEP
Sorry, William. You have to be the Executive Director of a non-profit or similar to get a month vacation. If you¹re a NABCEP Certified Installer, it is catch as catch can. (I can attest to that.) However, there probably aren¹t a lot of out of work NABCEP Certified Installers. In all seriousness, one thing that gets lost in some of these discussions is that the relative value of ANY certification varies depending upon where one is in the food chain, so to speak. I¹ve worked in distribution, in design and integration, and now in technical publishing. As an employee, I¹ve found NABCEP certification super valuable. It has distinguished my resume from others. It sets a floor for my value in terms of compensation. In fact, when I worked for an installation firm, we had automatic pay raises for NABCEP Certification. If you¹re an owner of an installation firm, I think it¹s a very different scenario. Your past work is the best part of your resume. It¹s a lot easier to sell your company to future customers based on your long list of past happy customers than it is to explain to them what in the world NABCEP stands for and why they should care. I think it can be a selling point, but if your not an employee the value in NABCEP is definitely more symbolic and intangible. We all see a lot of mistakes that get made in our line of work. NABCEP represents the industry¹s own desire to set and strive for a higher standard. It¹s not the boogey man. It¹s not ³The Man.² It¹s your well intentioned colleagues. That¹s my experience and my 2 cents, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 6/2/12 9:34 AM, William Miller will...@millersolar.com wrote: Colleagues: I have been debating in my own mind the merits and demerits of applying for NABCEP. I see below the conclusive evidence that I should become certified. If NAPCEP installers get to take month long vacations, I'm all in. William Miller At 07:17 AM 6/2/2012, you wrote: The only person who would officially respond to Wrenches posts about NABCEP would be Ezra Auerbach, the Executive Director. That's part of his job, to be the public face for the organization. I have forwarded a few of these posts to him, and have gotten back a robo-response that he and his wife are away on vacation and will respond to emails upon return, I think around the end of June. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] WOW Something Gone Very Wrong
Perfect example of why it¹s a good idea to start designing and deploying systems now that meet the fuse servicing requirements found in NEC 2011even if these are not required by your AHJ yet. People on this list are probably ahead of that curve. If not, you might want to check out these articles: http://solarprofessional.com/article/?file=SP4_3_pg14_QA_2search= (Bill Brooks article on Fuse Servicing disconnect requirements) http://solarprofessional.com/article/?file=SP4_3_pg64_Hrensearch= (Changes to Code in 2011; See content under ³690.6, Fuses² subheading) David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 3/29/12 9:36 AM, Mark Frye ma...@berkeleysolar.com wrote: Rooftop solar installation sparks fires in Trenton, New Jersey 28.03.2012: According to local news portal NJ.com, a rooftop solar system has triggered several small fires at a recycling center in Trenton, New Jersey. The article reports that ³a major malfunction in the rooftop solar panelcaused small fires and surges of electricity producing arcs of current to break out.² According to Fire Battalion Chief Rich Seeds, ³There definitely was a problem with the installation, the equipment.² Firefighters on the scene said that an inverter was ³sparking and unusable.² The firefighters, with the help of electricians, had to manually disconnect the 100-panel system from the electrical grid before they could safely put out the fire. The fire started while electricians were hooking up junction boxes on the system. Earlier this month, a New Jersey General Assembly committee approved a bill (A266) that would require buildings to clearly label with an exterior emblem whether they have solar panels installed on the premises. The measure, recommended by the National Fire Protection Association, is aimed at protecting firefighters from dangers posed by solar panels. The greater Assembly has yet to discuss the bill, but the New Jersey Senate version of the bill (S507) was introduced in the Senate on Jan. 10, 2012 and is currently being reviewed by the Senate Environment and Energy Committee. Source: NJ.com, New Jersey Assembly Republicans, eLobbyist; Summary: PHOTON http://www.nj.com/mercer/index.ssf/2012/03/trenton_firefighters_battle _ro.html http://www.nj.com/mercer/index.ssf/2012/03/trenton_firefighters_battle_ro.htm l http://www.njassemblyrepublicans.com/?p=2862 http://www.njassemblyrepublicans.com/?p=2862 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] WOW Something Gone Very Wrong
That was my suspicion as well. Simple wiring mistake. Inadequate commissioning protocol. On 3/29/12 2:02 PM, Bill Brooks billbroo...@yahoo.com wrote: All, It is very likely that the something gone very wrong was a wiring mistake by the installing contractor. Many installers are clueless about the danger and consequences of getting the polarity wrong in strings or combiner box circuits. It is very likely that the contractor mixed up their combiner box circuits causing the combiner boxes and conductors to catch on fire as soon as the fuses were installed. Polarity should be checked and verified on all circuits a total of 2 or 3 times during the course of installation and commissioning. It is the single most important test from a safety point of view. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Thursday, March 29, 2012 8:25 AM To: RE-wrenches Subject: Re: [RE-wrenches] WOW Something Gone Very Wrong Perfect example of why it¹s a good idea to start designing and deploying systems now that meet the fuse servicing requirements found in NEC 2011even if these are not required by your AHJ yet. People on this list are probably ahead of that curve. If not, you might want to check out these articles: http://solarprofessional.com/article/?file=SP4_3_pg14_QA_2search= (Bill Brooks article on Fuse Servicing disconnect requirements) http://solarprofessional.com/article/?file=SP4_3_pg64_Hrensearch= (Changes to Code in 2011; See content under ³690.6, Fuses² subheading) David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 3/29/12 9:36 AM, Mark Frye ma...@berkeleysolar.com wrote: Rooftop solar installation sparks fires in Trenton, New Jersey 28.03.2012: According to local news portal NJ.com, a rooftop solar system has triggered several small fires at a recycling center in Trenton, New Jersey. The article reports that ³a major malfunction in the rooftop solar panelcaused small fires and surges of electricity producing arcs of current to break out.² According to Fire Battalion Chief Rich Seeds, ³There definitely was a problem with the installation, the equipment.² Firefighters on the scene said that an inverter was ³sparking and unusable.² The firefighters, with the help of electricians, had to manually disconnect the 100-panel system from the electrical grid before they could safely put out the fire. The fire started while electricians were hooking up junction boxes on the system. Earlier this month, a New Jersey General Assembly committee approved a bill (A266) that would require buildings to clearly label with an exterior emblem whether they have solar panels installed on the premises. The measure, recommended by the National Fire Protection Association, is aimed at protecting firefighters from dangers posed by solar panels. The greater Assembly has yet to discuss the bill, but the New Jersey Senate version of the bill (S507) was introduced in the Senate on Jan. 10, 2012 and is currently being reviewed by the Senate Environment and Energy Committee. Source: NJ.com, New Jersey Assembly Republicans, eLobbyist; Summary: PHOTON http://www.nj.com/mercer/index.ssf/2012/03/trenton_firefighters_battle _ro.html http://www.nj.com/mercer/index.ssf/2012/03/trenton_firefighters_battle_ro.htm l http://www.njassemblyrepublicans.com/?p=2862 http://www.njassemblyrepublicans.com/?p=2862 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] calculating low string voltage
-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] calculating low string voltage
Here¹s a link to an Excel version of our c-Si PV module specifications table: https://solarprofessional.com/webexclusive/ It includes coefficients for Voc, Pmp and Isc. For Vmp calculations, use the coefficient of Pmp, which is primarily voltage driven. (Temperature coefficients of current are VERY small, as seem in the Isc values.) David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 11/30/11 12:18 AM, Ray Walters r...@solarray.com wrote: I pulled the voltage temp coefficient off of an article from Solar Pro Magazine. It is indeed listed for Voc. I have never seen a separate coefficient for Vmpp. Maybe we should use the Power mpp coefficient and then factor the slight rise in current by temp (which would make Vmpp even worse). My Solar world example shows a Pmpp coeff. of -0.47, while the current coeff. (short circuit though) is positive 0.04 so correcting just for voltage, that would be at or slightly worse than Bill's suggested -0.5 coefficient for Vmpp. Which would pull the Vmpp from 35 to 28 in my example, not 30.4 v. The degradation and mismatch Bill points out make sense, but is it really another 15% combined? Would it be fair to say different modules and manufacturers would degrade at different rates? Finally, the ambient temp I picked was the opposite of the NEC suggested ASHRAE low temp. Is that really the best number for calculating this? Or is that too extreme a temperature, that wouldn't occur most of the time? Now I have to correct that coefficient for my next class..but that's why I asked for everybody to look it over. Thanks Everyone, Ray On 11/29/2011 8:08 PM, Doug Wells wrote: Ray, I agree with what you have calculated, but the temp. coef. listed is for a Voc. For voltage sag, the temp. value would be a Vmp value and I don't know how much of a difference that makes. I have seen some manufacturers offer a temp. coefficient for Vmp as well as Voc. Not sure what the difference would be, but if it gets down to a few volts with the PE, it is would be worth checking. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com http://www.thesolarspecialists.com On Nov 29, 2011, at 5:55 PM, Ray Walters wrote: I'm prepping for a class on this very subject tonight, so I'll just wrap up everybody's good points: V min = Vmpp x (1- temp diff x Temp coefficient) So first, I'd take your ambient temp from ASHRAE Extreme Annual Mean Maximum, then add Scott's adder (ie roof mount off 6 = +30C) so let's say the ASHRAE # is 35C, then you have 30 + 35 = 65C cell temp then, 65C - 25C(STC) = a differential of 40 deg C from standard test conditions The Aug/ Sept 2010 edition of Solar Pro shows the coefficients for numerous modules, Solar world for example is -0.33 %/degC With a 40 degC differential then, the voltage would change by 40 x .33, or 13.2% So just assuming Vmpp = 35v, the adjustment would be 35v x (100%-13.2%), or 86.8% of 35v, which gives a Volt min of 30.4 v Somebody please correct my math if I got that wrong. Also probably more interesting is the actual Power coefficient, which shows the total power losses from higher temperatures, not just voltage. The calculation would be similar. Ray On 11/29/2011 2:07 PM, Darryl Thayer wrote: I am on road so I have no texts with me, but the same formula applies about 0.4% per degree (less voltage) or use the module label voltage coefficent. However you must use the MPPT voltage and the temperature = (temperature ambient (2% high) plus roof temperature warming) The roof temperature is hard to find good values because it depends upon spacing between roof and module. I add 15 deg C for most situations. Best I can do from memory. DT From: Kirk Herander k...@vtsolar.com mailto:k...@vtsolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org mailto:re-wrenches@lists.re-wrenches.org Sent: Tuesday, November 29, 2011 1:48 PM Subject: [RE-wrenches] calculating low string voltage I am in debate with a PE over calculation of low voltage of a series string on a hot day. He insists that an arbitrary high cell temp is factored in, not just ambient temperature. Could someone please give an accepted formula for this calculation? Thanks. I cannot find a clear reference to low voltage calculation on a hot day (but every reference material is clear on how to calculate high voltage on a cold day). Kirk Herander VT Solar, LLC dba Vermont Solar Engineering NABCEPTM Certified installer Charter Member NYSERDA-eligible Installer VT RE Incentive Program Partner
Re: [RE-wrenches] Adding on to existing PV System
Agreed. The intent of the change to 690.64(B) in NEC 2008 was not to restrict the use of a dedicated inverter aggregation subpanel for amp-shaving purposed (meaning the panel is being used to reduce the PV CB size ultimately used for 120% rule calculations). The intent was to clarify the that there is no need to apply the 120% rule to progressively larger upstream breakers when the interconnection happens in a subpanel. A reasonable inspector or jurisdiction will interpret the Code consistent with its intent, not according to an unintended consequence. However, you may have to educate them about the distinction between the two possible interpretations. David Brearley, Senior Technical Editor SolarPro magazine On 9/29/11 1:50 PM, Mark Frye ma...@berkeleysolar.com wrote: OK, this subject has come up before and this is a gray area in the Code. What is the definition of the output of the inverters. I have sucessfully argued that the output of the inverters is the last point in the circuit where the circuit is free of premise load circuits. In this case it would be the 40A breaker connecting the dedicated PV load center to the busbar of the main panel. So...it is between you and you inspector. Tell him you are going to put a label on the subpanel that says something to the effect of Dedicated inverter output accumulation subpanel. Add no additional circuits. I think this is a much better interpretation and method that preserves a clean and functional load side connection topology. I think most reasonable inspectors would agree as well. Good Luck. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com http://www.berkeleysolar.com/ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Thursday, September 29, 2011 1:33 PM To: RE-wrenches Subject: Re: [RE-wrenches] Adding on to existing PV System I understand what you are saying about the 40A breaker, but according to 690.64(B)(2), ³with panelboards connected in series, the rating of the *first* overcurrent device connected *directly* to the output of the inverters shall be used in the calculations for *all* busbars and conductors.² The way I have seen that interpreted is that the main distribution panel needs to be rated to support 120% of the two inverter circuits plus the main breaker, regardless of the fact that there is a 40A backfeed breaker in the main panel. 200+30+15 200 x 1.2 I know it doesn¹t make much sense, but that¹s the way it¹s been interpreted around here. It stands to reason that this applies only to the PV subpanel busbar and the conductors between the panels, and that the calculation for those should be: (30 + 15 + 40) / 1.2 = 70.83A required ampacity and the calculation for the main distribution panel should be: (200 + 40) / 1.2 = 200A required ampacity but that¹s not what I am being told. Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye Sent: Thursday, September 29, 2011 4:19 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] Adding on to existing PV System Jason: SB 5000 = 21A @ 240V, 21A x 1.25 = 26.3A needs 30A breaker M215 = 0.9 A @ 240V, 0.9A x 9 = 8.1 A, 8.1 x 1.25 = 10.1A needs 15A breaker. (Or that rounded to 10A and use a 10A breaker)? 26.3A + 10.1A = 36.4 A needs 40A breaker So, get a new 100A main lug subpanel. Connect it to a 40A breaker in the existing main panel. Move the existing 30A breaker into the new subpanel and install the new 15A breaker into the same. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com http://www.berkeleysolar.com/ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Thursday, September 29, 2011 12:55 PM To: RE-wrenches Subject: Re: [RE-wrenches] Adding on to existing PV System That¹s not a bad idea, except that 690.64(B)(2) requires that the breaker directly connected to each inverter(s) must be used for the calculation. I have an existing SB5000 with a 30A breaker and a new string of nine Enphase M215¹s requiring a 15A breaker. If you combine these in a 100A or higher rated subpanel with a 40A main breaker, you still calculate the total current supplying the busbar in the main distribution panel based on 200A + 30A + 15A = 245A (with 30A and 15A being the overcurrent protection directly connected to the inverters). This exceeds the 120% rule by 5A. It also requires that the ampacity of the conductors between the two panels be 85A / 1.2 = 70.83A (assuming a 40A backfeed breaker in the main distribution panel). If your interpretation is different
Re: [RE-wrenches] 1987 NEC
Hans, John Wiles described the evolution of this standard for a Home Power article that we referenced later in a SolarPro on PV System Ground Faults: http://solarprofessional.com/article/?file=SP2_5_pg60_Mync ³As described by John Wiles, program manager for the Institute for the Energy and the Environment, in the February/ March 2008 Home Power article Ground-Fault Protection Is Expanding, Article 690.5 was added to the NEC in 1987. One of Wiles¹ first projects in the PV industry was to develop ³prototype hardware² to meet the new Code requirement. The basic concept (of the original GFPD prototype), writes Wiles, was to insert a 0.5- or 1-amp circuit breaker in the dc system-bonding conductor. This small circuit breaker senses any current between the grounded current-carrying conductor and the grounding system, tripping if current exceeds the 0.5 A or 1 A rating. By mechanically linking this smaller breaker to larger capacity breakers that are installed inline with the ungrounded current-carrying array conductors, it is possible to detect, interrupt and indicate that a ground fault has occurred, and to disconnect the fault. These early GFPDs were manufactured for 48 V or lower PV systems. According to Wiles, ³As higher voltage, utility-interactive PV inverters became available in the late 1990s, using a 0.5- or 1-amp fuse as the sensing element and the inverter¹s control electronics to monitor the fuse was more cost effective.² While the sensing equipment may have changed, in general the role of the modern GFPD remains the same as it was in 1987: 1. Detect ground faults in PV arrays. 2. Interrupt the fault current. 3. Indicate that a ground fault has occurred. 4. Disconnect the faulted part of the array. These four GFPD requirements for grounded PV arrays are spelled out in NEC 690.5(A) and 690.5(B). The former requires ground-fault detection and interruption (GFDI), which includes the provision to indicate the presence of a ground fault. The latter requires that faulted circuits be isolated either by disconnecting the ungrounded conductors of the faulted circuit or by shutting down power to the output power circuits of the inverter or charge controller. A final GFPD requirement is found in Article 960.5(C), which calls for a visible warning in the proximity of the ground-fault indicator. The warning could be an LED, an LCD or both. In general, the manufacturer provides this electric shock hazard warning as part of the listed grid-tied inverter or charge controller. However, where a PV system includes batteries, the installer must apply a duplicate warning label near the batteries, stating: WARNING ELECTRIC SHOCK HAZARD IF A GROUND FAULT IS INDICATED, NORMALLY GROUNDED CONDUCTORS MAY BE UNGROUNDED AND ENERGIZED One change in the GFPD requirements introduced in 1987 is that it is no longer necessary to short-circuit, or ³crowbar,² the PV array in the event of a ground fault. This added step had the effect of reducing the PV array voltage to zero, minimizing shock hazard. The requirement was dropped in a subsequent Code cycle, as leaving the array in a short-circuited condition created several other issues.² If you¹re a Home Power subscriber, you can access the original article in the HP archives. If not, it is summarized above. Best, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 7/19/11 2:19 PM, Hans Frederickson h...@fredelectric.com wrote: Kent, I'm not a geezer yet, but thanks to my dad I do have a copy of the 1987 NEC. 690-5 (Ground Fault Detection and Interruption) was added in the 1990 NEC. There is no 690-5 or mention of ground fault detection/interruption in the 1987 NEC. In the 1990 NEC, section 690-5 is very small compared to 690.5 in the 2011 NEC. Here's the complete text from 1990: 690-5. Ground Fault Detection and Interruption. Roof-mounted photovoltaic arrays located on dwellings shall be provided with ground-fault protection to reduce fire hazard. The ground-fault protection circuit shall be capable of detecting a ground fault, interrupting the fault path, and disabling the array. The handbook for 1990 goes on to say that the gfp device must: 1) detect the ground fault 2) open the grounded conductor to interrupt the ground fault 3) open the ungrounded conductors and short the photoltaic array source to disable it For some reason, I've never heard of item #3, specifically the part about shorting the array. Can anyone shed light on this? Regards, -Hans From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Monday, July 18, 2011 10:07 PM To: g...@icarussolarservices.com; RE-wrenches Subject: Re: [RE-wrenches] 1987 NEC Gary, No one else has come up with a 1987 NEC. If you can get a copy of 1987 section 690.5 (I think it was 690-5 back
Re: [RE-wrenches] 1987 NEC
Presumably the latteradded as part of the cycle of revisions initiated in 1987. On 7/19/11 3:29 PM, Hans Frederickson h...@fredelectric.com wrote: David, Thanks for the interesting history on GFPDs. My copy of the 1987 NEC does not have 690-5, and it's not missing any pages. Either my code book is an incomplete printing or perhaps John Wiles was referring to a 1987 proposal that didn't make it into the code until the 1990 NEC. Regards, -Hans From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Tuesday, July 19, 2011 12:57 PM To: RE-wrenches Subject: Re: [RE-wrenches] 1987 NEC Hans, John Wiles described the evolution of this standard for a Home Power article that we referenced later in a SolarPro on PV System Ground Faults: http://solarprofessional.com/article/?file=SP2_5_pg60_Mync ³As described by John Wiles, program manager for the Institute for the Energy and the Environment, in the February/ March 2008 Home Power article Ground-Fault Protection Is Expanding, Article 690.5 was added to the NEC in 1987. One of Wiles¹ first projects in the PV industry was to develop ³prototype hardware² to meet the new Code requirement. The basic concept (of the original GFPD prototype), writes Wiles, was to insert a 0.5- or 1-amp circuit breaker in the dc system-bonding conductor. This small circuit breaker senses any current between the grounded current-carrying conductor and the grounding system, tripping if current exceeds the 0.5 A or 1 A rating. By mechanically linking this smaller breaker to larger capacity breakers that are installed inline with the ungrounded current-carrying array conductors, it is possible to detect, interrupt and indicate that a ground fault has occurred, and to disconnect the fault. These early GFPDs were manufactured for 48 V or lower PV systems. According to Wiles, ³As higher voltage, utility-interactive PV inverters became available in the late 1990s, using a 0.5- or 1-amp fuse as the sensing element and the inverter¹s control electronics to monitor the fuse was more cost effective.² While the sensing equipment may have changed, in general the role of the modern GFPD remains the same as it was in 1987: 1. Detect ground faults in PV arrays. 2. Interrupt the fault current. 3. Indicate that a ground fault has occurred. 4. Disconnect the faulted part of the array. These four GFPD requirements for grounded PV arrays are spelled out in NEC 690.5(A) and 690.5(B). The former requires ground-fault detection and interruption (GFDI), which includes the provision to indicate the presence of a ground fault. The latter requires that faulted circuits be isolated either by disconnecting the ungrounded conductors of the faulted circuit or by shutting down power to the output power circuits of the inverter or charge controller. A final GFPD requirement is found in Article 960.5(C), which calls for a visible warning in the proximity of the ground-fault indicator. The warning could be an LED, an LCD or both. In general, the manufacturer provides this electric shock hazard warning as part of the listed grid-tied inverter or charge controller. However, where a PV system includes batteries, the installer must apply a duplicate warning label near the batteries, stating: WARNING ELECTRIC SHOCK HAZARD IF A GROUND FAULT IS INDICATED, NORMALLY GROUNDED CONDUCTORS MAY BE UNGROUNDED AND ENERGIZED One change in the GFPD requirements introduced in 1987 is that it is no longer necessary to short-circuit, or ³crowbar,² the PV array in the event of a ground fault. This added step had the effect of reducing the PV array voltage to zero, minimizing shock hazard. The requirement was dropped in a subsequent Code cycle, as leaving the array in a short-circuited condition created several other issues.² If you¹re a Home Power subscriber, you can access the original article in the HP archives. If not, it is summarized above. Best, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 7/19/11 2:19 PM, Hans Frederickson h...@fredelectric.com wrote: Kent, I'm not a geezer yet, but thanks to my dad I do have a copy of the 1987 NEC. 690-5 (Ground Fault Detection and Interruption) was added in the 1990 NEC. There is no 690-5 or mention of ground fault detection/interruption in the 1987 NEC. In the 1990 NEC, section 690-5 is very small compared to 690.5 in the 2011 NEC. Here's the complete text from 1990: 690-5. Ground Fault Detection and Interruption. Roof-mounted photovoltaic arrays located on dwellings shall be provided with ground-fault protection to reduce fire hazard. The ground-fault protection circuit shall be capable of detecting a ground fault, interrupting the fault path, and disabling the array
Re: [RE-wrenches] Single phase to three phase interconnect
Eric, Marvin Hamon, a PE in CA, wrote an article for SolarPro magazine on this topic that may be of assistance: http://solarprofessional.com/article/?file=SP3_1_pg66_Hamonsearch= David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/25/11 1:01 PM, Eric Thomas solarepiph...@gmail.com wrote: While commercial solar work is newer to me, im surprised this hasn't been addressed very much in our forum: Interconnecting single phase inverters to three phase services. We are laying out a 6kW system using Silicon Energy Cascade modules and Aurora PVI inverters (either 2 or 3 PVI 3.0's). The challenge is finding a way to easily tie two of these inverters into the existing 3phase service. I've been reading up on Sunny Boys tech notes and on this forum about imbalance and such, but im still not comfortable enough with tie in. Due to the string configuration options, I can add a third inverter and use a three phase subpanel to aggregate the inverters then tie them in. But adding a third inverter seems like a goofy solution. In looking at available equipment, transformers, phase converters etc, I can't seem to find the right fit. Any ideas? This system does not have a three phase inverter option due to Made in WA req's. Thanks! Eric Thomas Solar Epiphany LLC ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] PV to 208v 3-phase with high leg
Charlie, The installation manuals for the inverters you work with should clarify the acceptable service configurations. That¹s where I would start. (Actually, verify the service type first by having your electrician take line-to-line and line-to-neutral measurements at the service.) If you¹re talking about a 240 delta service with a 208 V high leg, you could interconnect a 3-phase central inverter that doesn¹t require a neutral connection; I believe Satcon fits this description. Or you could stack single-phase inverters line-to-line with at least one of the inverters configured such that it doesn¹t need to see the neutral. There may be a specific pin configuration that you need to set inside the inverter to enable operation without the neutral. This John Berdner article on scaling up PV system designs appeared in the very first issue of SolarPro and includes some electrical service type diagrams that may be helpful: http://solarprofessional.com/article/?file=SP1_1_pg32_Berdner David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/7/11 11:06 PM, Aladdin Solar cpick...@aladdinsolar.com wrote: What is the best approach to interconnecting with a 208 volt 3-phase service having a high leg? Small to medium sized PV systems. Charlie Pickard Aladdin Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] sizing a sub-panel used to combine multiple inverter outputs
This is diagram is based on a 3-phase 208 V service, as clarified in the text accompanying the diagrams. There is a mistake of sorts, however. The authors¹ original manuscript called out a ³generic² 7500W inverter connected to 50A, 2-P breaker. We then added more detail, calling out a Fronius 7500W IG Plus inverter. However, according to the most recent product data from the manufacturer, the max AC OCPD rating for this inverter is 45A, not 50A. The example still works w/ 45A breakers: 400A + 90A = 490A, which is larger than the 480A allowed under the 120% rule. Apply the subpanel that problem is eliminated. RE: the question about which breaker to count. Code experts like Bill Brooks John Wiles have clarified that when a dedicated inverter aggregation panel is used, the breaker on the output of the panel can be considered ³the output of the utility interactive inverter(s).² The intent of the language in 690.64(B)(2) in NEC 2008 about series connected panels is not to make you count all of the breakers in a dedicated inverter aggregation panel. Rather it is to clarify that it is unnecessary use the progressively larger upstream breakers ratings, which can be ³fed² by the inverters, in your point of connection calculations. RE: the original question. I think the most correct answer is ³It depends.² It depends on your jurisdiction and your PE. A literal interpretation of the Code would appear to have you upsize the inverter aggregation panel and the feeder conductor. But there is certainly precedent for AHJs not requiring this. If you propose labeling the inverter aggregation panel ³PV Only Do Not Add Loads² and mark the feeder conductor with warnings ³PV Only Do Not Tap² wherever it is exposed, you may find that the AHJ will not require you to upsize these. Hope that¹s cleared than mud, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 3/30/11 11:12 AM, Kent Osterberg k...@coveoregon.com wrote: Jason, Now you are opening up a can of worms. It's bad enough that 705.12(D) doesn't say anything about a panel that can't (or shouldn't, or won't) have anything connected but interactive inverters. But when that is the case, a bus rating of 100% of the source circuits should apply. For PV systems a 125% factor will already apply to each inverter circuit. While it seems logical that the conductors are an extension of the bus bar and should be treated the same way, 705.12(D) isn't about the conductors - it's about the bus bars. The conductors are protected by the breakers -- 80-amp breakers and wire with 80-amp ampacity. Getting into the example further, I see flaws in it. If the inverters are 7500-watt 240-volt, the output current would be 7500/240 = 31.25 amps and 40-amp breakers would be adequate. Then there would have been no issues, even going directly into the main panel. If the inverters are 7500-watt 208-volt, the output current is 7500/208 = 36 amps and the 50-amp breakers make sense. That means the bus bars and feeder conductor have a continuous current of 72 amps. That means neither the 80-amp breaker nor 80-amp wire is sufficient because 72 x 1.25 = 90 amps. Now the example doesn't resolve the limitation of backfeeding at the main. Opps! Kent Osterberg Blue Mountain Solar Jason Szumlanski wrote: Another key is to remember that this discussion also applies to the conductor between the main panel and subpanel. In a large PV system, this could result in a pretty large wire between the two panels, and a significant cost that is often overlooked. In some cases it makes sense to locate the subpanel close to the main panel and run multiple sets of smaller wires from the inverters to the subpanel. And because the calculation is based on the first OC protection connected to the inverters, adding a main breaker (theoretically 80A in this example) in the subpanel doesn¹t change things. Even though this wire would be theoretically protected by an 80A breaker at each end, you can¹t size the wire for 160A / 1.2 = 133.3A. You have to size for 180A/1.2 = 150A. (not that it makes much of a difference in this example, but it still must be considered) At least that¹s how I understand it Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye Sent: Wednesday, March 30, 2011 1:33 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] sizing a sub-panel used to combinemultipleinverter outputs Opps! My bad, I was thinking of a single phase system, not the three phase system shown in the article. For the three phase system Kent is correct in counting 180A of supply per bar. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way
Re: [RE-wrenches] sizing a sub-panel used to combine multiple inverter outputs
Agreed: http://solarprofessional.com/article/?file=SP2_3_pg16_QandA_2search= You¹ll notice that none of the more permissive proposals that John mentions here actually made it into NEC 2011. On 3/30/11 1:07 PM, Jason Szumlanski ja...@fafcosolar.com wrote: Here is a 690.64(B)(2) opinion from Wiles that may help. http://www.fafcosolar.com/download/409/690%2064%28B%29%282%29TECH-1.pdf It¹s still my contention that the conductors need to be sized for 150A in this example, unless an exception is made by the AHJ. If David Brearley¹s post about Wiles¹ clarification is accurate, them the 80A main breaker in the subpanel can be used for calculations, but the conductor still needs to be sized for 80A + 80A =160A / 1.2 = 133.3A. Jason From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Wednesday, March 30, 2011 12:57 PM To: RE-wrenches Subject: Re: [RE-wrenches] sizing a sub-panel used to combine multiple inverter outputs Al, How about a 15-amp single-pole breaker for power line carrier communications equipment to talk to the inverters? Technically, I think either way they are loads and that changes everything. But in my opinion they are minor and should be allowed without considering the sum of all sources. Kent Osterberg Blue Mountain Solar Al Frishman wrote: Is a monitoring system installed in the Load Center to measure the cumulative kWh¹s of the inverter¹s considered a load? The type of monitoring device I am talking about has CT¹s that go around the conductors and the Voltage ref is taken by attaching conductors to each phase, the Neutral and the ground bar.The digital Meter has a 3-pole 5A breaker in it so the conductors in the load center can be connected to lugs on the bus bar directly. Al Frishman AeonSolar (917) 699-6641 - cell (888) 460-2867 www.aeonsolar.com http://www.aeonsolar.com/ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Wednesday, March 30, 2011 8:18 AM To: RE-wrenches Subject: Re: [RE-wrenches] sizing a sub-panel used to combinemultipleinverter outputs Another key is to remember that this discussion also applies to the conductor between the main panel and subpanel. In a large PV system, this could result in a pretty large wire between the two panels, and a significant cost that is often overlooked. In some cases it makes sense to locate the subpanel close to the main panel and run multiple sets of smaller wires from the inverters to the subpanel. And because the calculation is based on the first OC protection connected to the inverters, adding a main breaker (theoretically 80A in this example) in the subpanel doesn¹t change things. Even though this wire would be theoretically protected by an 80A breaker at each end, you can¹t size the wire for 160A / 1.2 = 133.3A. You have to size for 180A/1.2 = 150A. (not that it makes much of a difference in this example, but it still must be considered) At least that¹s how I understand it Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye Sent: Wednesday, March 30, 2011 1:33 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] sizing a sub-panel used to combinemultipleinverter outputs Opps! My bad, I was thinking of a single phase system, not the three phase system shown in the article. For the three phase system Kent is correct in counting 180A of supply per bar. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com http://www.berkeleysolar.com/ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye Sent: Tuesday, March 29, 2011 10:17 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] sizing a sub-panel used to combine multipleinverter outputs I think Kent and I agree. For the case where the subpanel is not dedicated a PV sub-panel he is calculating for 2 - 50A breakers and I calculated for 3 - 50A breakers. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com http://www.berkeleysolar.com/ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, March 29, 2011 9:26 PM To: RE-wrenches Subject: Re: [RE-wrenches] sizing a sub-panel used to combine multiple inverter outputs Per 705.12(D) the sub-panel could be any distribution equipment on the premises. So the question becomes: is the sub-panel capable of supplying branch circuits or feeder loads? If yes, then the sum of the breakers (potentially) feeding the bus is 180
Re: [RE-wrenches] NABCEP marketing
The lesson here might be: Use the right tool for the job. NABCEP probably limits battery-based system questions to 5% of its test questions these days. The test reflects the market. You can totally pass the test without battery-based system knowledge; it helps if you have it, of course, but most PV system installers these days don¹t. Let¹s be honest. The experience on this listserve is not representative of the market at large. Off-grid system integration is so specialized that hiring Larry the Wirewizwho has worked installing stand-alone power systems on boats for 30 yearsprobably makes more sense in this case than hiring a NABCEP Certified Master Electrician, especially if the company they work for does grid-tied work as a rule. My personal opinion is that voluntary NABCEP Certification is so much better, especially for experienced PV professionals, than the other options. I¹m glad the people within the industry took the initiative to try and set some sort of benchmark or standard for solar installers. Without it, the only benchmark is state licensing, which in many cases doesn¹t provide solar installers with a specialized track. The NABCEP test isn¹t perfectbig surprisebut let¹s be realistic about the limits of any multiple choice test. As far as NABCEP hurting anyone¹s business, that seems like a stretch to me. Customer¹s don¹t know what NABCEP is. It¹s unlikely that it will be adopted as some sort of national licensing standard. The same cannot be said for UL or the UL Certification for PV installers, which I suspect is a much more likely to marginalize experienced, veteran solar installers than NABCEP is. When I look into my crystal ball, I see solar bozos, NABCEP certified or not, competing against UL Certified PV Installation Companies, that are all licensed electrical contractors, likely new to solar. Off-grid systems is one of the few places where I see solar bozos coming out ahead in that competition. Everyone recognizes UL, even if they don¹t know what it means or does. If you don¹t want to be NABCEP Certified, don¹t take the test. But I don¹t see where bashing an organization that is trying to do something to legitimize or mainstream this industry deserves any contempt either. This is just my opinion and not the opinion of my esteemed employer. And I¹m not trying to offend anyone, either. I just see a lot of wrinkles to this. Sorry for the rant, David Brearley On 2/8/11 2:04 PM, hol...@sbcglobal.net hol...@sbcglobal.net wrote: My electrician was out of pocket, so I hired a master electrician with NABCEP citification from a highly reputable company to complete a battery based system for me with the expectation that he would: 1) verify that my initial design would be to code and within proper operating parameters 2) change any components that did not satisfy his interpretation of code and make recommendations to any performance issues 3) communicate these changes to me so that I could have specified components on site upon his arrival or in a timely manner so that the job may be completed within the time frame allotted 4) verify all components were installed to either initial or modified specs and to code 5) turn on system to verify all components were operating properly What I got was: * Array wired incorrectly - he had written instructions. 20 modules to be 5 strings of 4, he wired array 4 strings of 5...the CC's front end mosfets appear to be fried due to overvoltage * ground conductor not run to combiner at array * make do fittings at combiner - they were job-site adjusted - not liquid tite * battery cable not run to shunt * grounding not completed at power shed (system was turned on without this being done) * improper grounding at house sub-panel * Mate plugged into inverter port 3 at Hub * No twisted pair run from CC to shunt * many times that I arrived on site there was much looking around in the trailer to find something that would work a certified guy should know what is on the trailer and that it's properly inventoried before it goes to site... I didn't need to pass a test to find these errors that have cost me a pretty big chunk of moneywe all have bad days, but, come on, man. Conclusionsome people are good at passing tests, but not so good in the field. sent anonymously as possible to protect the innocent - Original Message - From: Dana mailto:d...@solarwork.com To: 'RE-wrenches' mailto:re-wrenches@lists.re-wrenches.org Sent: Tuesday, February 08, 2011 10:46 AM Subject: Re: [RE-wrenches] NABCEP marketing The questions that are presented on the Nabcep ³Problem² solving are short on realistic info and designed to really be multiple guess. Does this really qualify folks for the real world or just real guessing. Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C
Re: [RE-wrenches] module / panel
People in and out of the industry misuse the term PV panel all the time. The NEC is pretty clear that the basic building block for a PV system is a module, the complete unit. Assemble some of these together now you have a panel. (This is less common now that we have 250 watt modules and not 50 watt modules.) An array is defined in the NEC as a mechanically integrated unit; I tend to think of an array as all of the modules on site. They added a definition for a subarray in the 2011 NEC; this is an electrical subset of an array. On 2/8/11 4:49 PM, benn kilburn b...@daystarsolar.ca wrote: Wrenchers, Which term do you to describe a single framed unit with either a j-box or two wire leads on the back, module or panel? Which term do you believe to be correct and why? My interpretation is that a single framed unit is a module. Any number of modules attached to a single detached 'rack' is a panel, and a group of panels with the same orientation or mounting location/type is an array. If you agree with my interpretation, what are your thoughts on the widespread use of the term 'panel' to describe a module. thanks, benn DayStar Renewable Energy Inc. b...@daystarsolar.ca 780-906-7807 HAVE A SUNNY DAY ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] module / panel
However, the term panel does appear in the NEC in the context of Article 690 Solar Photovoltaic Systems. (You'll have to submit a proposal to the Code Making Panel to change the name of the Article, Michael.) Panel is defined a collection of modules mechanically fastened together, wired and designed to provide a field installable unit. The third photo down in this article shows modules being panelized (bottom left) and a panel being lifted into position by a crane (top right): http://solarprofessional.com/article/?file=SP3_4_pg26_Braysearch= On 2/8/11 5:19 PM, Michael Welch michael.we...@re-wrenches.org wrote: FYI, gang (and for what it is worth), Home Power magazine settled on the following long ago, and it seems consistent with other uses: A panel can be used to refer to something that captures heat energy, but does not use the photovoltaic effect. (Like SHW panel, but even SHW collector is what we usually use.) A single framed set of PV cells with said connecting method is a PV module. More than one PV module wired together in a set is an array (or a sub-array, which can also refer to mechanical connection). All the sub-arrays in a system constitute an array. Admittedly, there is some arbitrariness in there, but we wanted the magazine to be consistent. There is no such thing as a solar PV module or panel -- but if there was it would capture twice the amount of energy due to redundance. benn kilburn wrote at 02:49 PM 2/8/2011: Wrenchers, Which term do you to describe a single framed unit with either a j-box or two wire leads on the back, module or panel? Which term do you believe to be correct and why? My interpretation is that a single framed unit is a module. Any number of modules attached to a single detached 'rack' is a panel, and a group of panels with the same orientation or mounting location/type is an array. If you agree with my interpretation, what are your thoughts on the widespread use of the term 'panel' to describe a module. thanks, benn DayStar Renewable Energy Inc. b...@daystarsolar.ca 780-906-7807 HAVE A SUNNY DAY ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] module / panel
It tells me their marketing people have never read the NECno big surprise thereand maybe they are new to the PV industry. But the term PV panel is also used so ubiquitously in place of the term PV moduleboth in common parlance and in the industrythat it¹s probably going to supersede the terms in the NEC over time. Since the NEC terms were defined when modules were 50W each, one could make the case that a 250W module bears some resemblance to a panel, as originally conceived. One new company that does know the difference is Solyndra. Each cylinder in Solyndra-speak is a module. They refer to the field-installable assembly is a panel. Technically perfect use of the terms. My personal pet peeve is not keeping power and energy straight. We can all distinguish between between miles-per-hour and miles. So how come some people in this industry can¹t keep kW and kWh straight? That smells fishy to me, especially in ³technical sales² literature. On 2/8/11 5:20 PM, benn kilburn b...@daystarsolar.ca wrote: Dave, thanks for the reply. What are your thoughts when you see (in various publications and/or websites) solar PV distributers and even module manufacturers using the term 'panel' to describe a 'module'? benn DayStar Renewable Energy Inc. b...@daystarsolar.ca 780-906-7807 HAVE A SUNNY DAY Date: Tue, 8 Feb 2011 17:02:32 -0600 From: david.brear...@solarprofessional.com To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] module / panel Message body People in and out of the industry misuse the term PV panel all the time. The NEC is pretty clear that the basic building block for a PV system is a module, the complete unit. Assemble some of these together now you have a panel. (This is less common now that we have 250 watt modules and not 50 watt modules.) An array is defined in the NEC as a mechanically integrated unit; I tend to think of an array as all of the modules on site. They added a definition for a subarray in the 2011 NEC; this is an electrical subset of an array. On 2/8/11 4:49 PM, benn kilburn b...@daystarsolar.ca http://b...@daystarsolar.ca wrote: Wrenchers, Which term do you to describe a single framed unit with either a j-box or two wire leads on the back, module or panel? Which term do you believe to be correct and why? My interpretation is that a single framed unit is a module. Any number of modules attached to a single detached 'rack' is a panel, and a group of panels with the same orientation or mounting location/type is an array. If you agree with my interpretation, what are your thoughts on the widespread use of the term 'panel' to describe a module. thanks, benn DayStar Renewable Energy Inc. b...@daystarsolar.ca http://b...@daystarsolar.ca 780-906-7807 HAVE A SUNNY DAY ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org http://RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com http://david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http
Re: [RE-wrenches] Roofers installing solar = creative, new installation methods
Good points. Also, adding a PV system is in concert with a new roof is generally a best case scenario for the building owner. In terms of lead generation, it can also go both ways. Solar companies help generate business for the roofing contractors they recommend to customers or partner with on projects. There¹s definitely a win-win way of looking at this. (While roofing contractors are hardly the first solar installers to make rookie mistakes, failing to attach a system to a sloped roof is particularly egregious. The best ³worst PV install² story I heard involved first-generation Uni-solar shingles installed on a north facing roof without enough modules in series to actually reach the inverter start voltage. At least it didn¹t blow away or fall off the roof!) David Brearley, Senior Technical Editor SolarPro magazine On 1/28/11 11:57 AM, Keith Cronin electrich...@yahoo.com wrote: Andrew Perhaps another approach could be warranted? Joint venture relationships can serve each party well, as long as their structured in a way that benefits the companies involved. Roofers are a good source of leads for us and visa versa. Its worked for me and I know of others that also see value in this across the country. The work we do, in the grid tied arena falls into two generally accepted categories: Mechanical work Electrical work Yes, some jurisdictions may say it is all electrical work and finding a demarcation point is open to discussion, but this is how its being performed across the globe now. If we like it or not, its going to continue. Here in our market there are over 150 companies (that I can count) doing PV. When I started, there where about 6. General contractors and the like. They need electrical contractors to perform the electrical portion of the work. In many ways, many of these other types of contracting companies are far better at lead generation, marketing and sales than the top electrical contractors and here is why- historically, electrical contractors have subordinated themselves to general contractors and are bidders. Even today, many of my electrical contractor competitors are ok, with just doing the installation work for the general contractors or sales and marketing companies, as they want to focus on doing the work only and don't have the temperament for running a sales force. Lastly, I believe you can offer other ancillary services to your customers, increasing the value of the relationship that have higher margins than the commoditized residential pv markets today. So, I think we all need to do like Darwin mentioned and adapt to the market conditions, so we can not just survive, but thrive in our gold rush. How about a residential PPA for your customers to differentiate? Aloha Keith From: Solar Energy Solutions solarenergysoluti...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Fri, January 28, 2011 6:41:29 AM Subject: Re: [RE-wrenches] Roofers installing solar = creative, new installation methods Joel, Our company cannot survive without selling an entire system. When we help the unqualified and untrained we legitimize unsubstantiated pv businesses. We get a dozen phone calls a month from folks wanting us to install their systems. It is a rat hole and we have learned that not only are such ventures unprofitable, they are fraught with poor designs and a plethora of other hassles. This whole thing reminds me of the Carter solar Gold Rush where, sure, a bunch of systems were installed, but look at the damage it did to the industry. Respectfully, Andrew Koyaanisqatsi President Solar Energy Solutions, Inc. Since 1987, Moving Portland and Beyond to an Environmentally Sustainable Future. 503-238-4502 www.solarenergyoregon.com http://www.solarenergyoregon.com/ Better one's House too little one day than too big all the Year after. --- On Fri, 1/28/11, Joel Davidson joel.david...@sbcglobal.net wrote: From: Joel Davidson joel.david...@sbcglobal.net Subject: Re: [RE-wrenches] Roofers installing solar = creative, new installation methods To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Friday, January 28, 2011, 7:06 AM Guys, You're missing a business opportunity. Instead of complaining about roofers' bad work and competition, show the company owners photos of their screw-ups and your quality work. Tell him that he is a risk. Then offer to do their design and electrical installation (let them do the sales, roofing, and grunt work). Joel Davidson - Original Message - From: Warren Lauzon http://us.mc318.mail.yahoo.com/mc/compose?to=war...@wind-sun.com To: RE-wrenches http://us.mc318.mail.yahoo.com/mc/compose?to=re-wrenc...@lists.re-wrenches. org Sent: Friday, January 28, 2011 3:35 AM Subject: Re: [RE-wrenches] Roofers installing solar = creative,new installation methods We have seen a lot of the roofing companies nibbling around the edges
Re: [RE-wrenches] Cable Sizing - revisited, Ambient Temp
John, Bill has written an article for SolarPro that you may find relevant: http://solarprofessional.com/article/?file=SP3_6_pg68_Brookssearch= Here¹s an excerpt: ³...it is important for system designers to perform detailed low dc voltage calculations for specific array configurations. Designers should use the highest expected continuous ambient temperature for calculation purposes. According to the Copper Development Association, the highest ASHRAE temperature data that is likely to create a 3-hour continuous condition, per the definition of continuous found in NEC Article 100, is the 2% Annual Design Dry Bulb Temperature, which is also found in Appendix E of the Expedited Permit Process for PV Systems. For designers who feel that the ASHRAE 2% temperature is not high enough, the same table also includes ASHRAE Extreme Annual Mean Maximum Design Dry Bulb Temperature data, which can be used for even more conservative voltage or ampacity calculations.² I realize you are talking about a different set of calculations, but the rationale for which data to use may still apply. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 1/27/11 1:20 AM, John Wadley wadle...@hotmail.com wrote: Dave, Thanks for responding in Mr. Brooks place. Since ASHREA 2% is not the very worst case, it seems like it might be possible for the ampacity of the wire chosen to dip below the rating of the OCPD protecting it, if there is not much margin. I've been trying to rationalize whether this would become a safety issue. I don't think it would since the OCPD protects the wire from a current source increasing beyond the expected design output. I don't think there is much chance of that for a PV module (unless there was a short between two strings). I think the increased heating would more likely increase wire resistance/voltage drop and lower production. With enough voltage drop, the inverter might shut off. I guess my new concern is in the most severe case where there is solar concentration on a short section of conduit. Here, the heating effect of both the elevated ambient temp and reduced wire resistance might lead to premature failure of the wire insulation. If the combined heating effects exceed the 90C rating of the wire, does the insulation embrittle or melt? In either case, I foresee a grounding fault, and if the GFCI failed, it could spark a fire. I know the best solution is to keep conduit shaded and avoid these worst case solar concentrating conditions. Sometimes. when I design a system for a new contractor, I don't always know exactly where they plan to run conduit on a roof (nor can I control it) and I start what-if'ing whether my design numbers will be conservative enough to prevent a system failure or a fire. Thanks and regards, John Wadley, PE NABCEP Certified Solar PV Installer (TM) Wadley Engineering ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] 2011 NEC and impact in the field
August, We're currently working on a SolarPro article on this topic. It will appear in SP4.3 (April/May 2011). As usual, there are a fair number of changes that impact PV installations. Our authors have done a good job, in my estimation, of pointing these out, discussing the implications, providing the reasoning behind the major changes. Should be a good introduction overview of the Code changes that impact PV installers. Also, starting with the 2011 NEC, Mike Holt is addressing Articles 690 705 as part of his Understanding NEC series. Look for his title, Understanding NEC Requirements for Photovoltaic Systems. Looking forward to getting my hands on a copy, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 1/13/11 10:35 AM, August Goers aug...@luminalt.com wrote: Hi All - My shiny new copy of the 2011 NEC handbook just came in the mail and I've started reading through it trying to decipher what changes we should be expecting in the future. Although California is now just adopting the 2008 NEC which I'm quite familiar with, many jurisdictions will honor the newer version of the code if we provide a good argument for them. That said, does anyone who's checked out the new code have any interesting comments or advice on changes that might affect us out in the field? Section 690.31(E) is interesting in that it has quite a few detailed requirements for running DC circuits inside the building. Now it looks like MC cable is acceptable but that there are many more strict requirements about how the conduit or cable must be run. Labeling the DC conduit and J-boxes is also going to be a change we'll have to get used to. Hopefully there will be new reasonably priced label sources available. I'm sure I'm not alone in saying that it's always been hard to find cost effective labels which can hold up through the elements. The grounding section also looks substantially updated. As always, fun new things coming our way. Best, August August Goers Luminalt Energy Corporation 1320 Potrero Avenue San Francisco, CA 94110 m: 415.559.1525 o: 415.641.4000 aug...@luminalt.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] NEC 690.64 (B) (2)
SolarPro also published an article on this subject, written by Marvin Hamon, PE, entitled ³Calculating 3-Phase Line Currents.² Subscribers can access the HTML version of the article at the URL below or click the ³PDF Version² link on that page to download the article as it appeared in the magazine: http://solarprofessional.com/article/?file=SP3_1_pg66_Hamonsearch= Best regards, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 12/7/10 8:47 AM, Glenn Burt glenn.b...@glbcc.com wrote: Al, SMA has a good whitepaper on their site covering this, and there was an article in a recent Solar Pro covering this topic as well Good Luck! Glenn Burt From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Al Frishman Sent: Tuesday, December 07, 2010 5:51 AM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] NEC 690.64 (B) (2) Wrenches, How do you apply NEC 690.64 (B) (2) when you have multiple single phase inverters distributed across the 3 phases of an electric-panel via 2 pole breakers? Do you simply add up the total of all over-current devices feeding the panel (Inverter 2-pole breakers and main breaker) or is there a 3 phase formula that gets applied? It seems logical that if the single phase inverters are connected with 2-pole breakers Distributed across the 3 phases then you would take the sum of what is on each phase. Any and all input on this topic is appreciated. Regards, Al Aeonsolar 917 699 6641 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] metering an outback system
Drake, Chris Freitas wrote an article on this topic in SP1.1, ³Form 12S Metering for Grid-Tied Systems w/ Battery Backup.² Here¹s a link to the article and a wiring diagram: http://solarprofessional.com/article/?file=SP1_1_pg16_QandA_3search= David Brearley, Senior Technical Editor SolarPro magazine On 8/10/10 7:57 AM, Drake Chamberlin drake.chamber...@redwoodalliance.org wrote: Hi Alex, The one meter hook up always seems confusing to me. I'm still confused. Do we have the AC IN at both the bottom left and top right? To me it seems that the AC OUT from the inverter would go to the upper left and the protected loads panel would be fed from the bottom left. I've never used this method, but would like to use it instead of the two meter method. Thanks, Drake At 12:19 AM 8/10/2010, you wrote: When metering for production here in Washington State, we use both sides in a 12s 120volt meterbase with fifth jaw. top right inverter ac in, bottom right ac from grid. top left from battery back up, bottom left from inverter ac in, fifth jaw neutral. this set up allows grid tied selling and battery saved energy selling to be metered while subtracting energy used to charge batteries and subtracting any power needed to run the inverter. hope this helps. contact me off list if you need the diagram (in office) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Lightning Protection System
Kelly, The company we used the most is Bonded Lightning Protection Systems: http://www.bondedlp.com/ They had local offices for our projects in Austin, TX and a regional HQ. Also, they had installed many of the lightning protection systems that we came across on existing buildings, including semiconductor fabs. We¹d also run into them regularly on new construction projects. Maybe they can help you or point you to a company that serves the NW? There must not be a lot of lightning activity in the areajudging by the absence of service providerswhich makes me wonder if this language is really appropriate for this particular project. Is it really a design standard for federal projects? Or is it just goo left in the bid package specifications from a site in a lightning prone region? Best, David On 8/2/10 1:34 AM, Kelly Keilwitz, Whidbey Sun Wind ke...@whidbeysunwind.com wrote: David, Sounds like a perfect solution to me. The UL website lists 14 pages of Listed Installers for lightning protection, about 70% located in the Southeast, and the closest to WA State in Utah or SoCal. Do you recall the name of any such firm you liked to work with and were reasonable with their bids? It would be nice not to have to cold call from such a large list. Kelly Keilwitz, P.E. Whidbey Sun Wind Renewable Energy Systems 987 Wanamaker Rd. Coupeville, WA 98239 ke...@whidbeysunwind.com PH FAX: 360.678.7131 NABCEP Certified PV Installer WA Electrical Administrator On Aug 1, 2010, at 8:24 AM, David Brearley wrote: Kelly, When I came across language like this in an RFP, my assumption was that we needed to work with a specialty lightning protection subcontractor, a firm listed by UL. I would call them up, give them a project description and request a quote, which I would build into our cost estimate for the project. Included in their scope of work is providing a ³UL Listed Lightning Protection Certificate.² You can include that scope of work as a line item in our proposal. If the proposal requires that you include resumes for key team members, you might also include the lightning company¹s bio as it shows you¹ve done your due diligence. On the projects that I managed in this fashion, the lightning protection company always came in after our construction was substantially complete. There may be cases where you want to coordinate the that scope of work differently and get them on site earlier. They should be able to tell you what will work best, based on the general project description and your specific equipment grounding scheme. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com On 7/31/10 3:28 PM, Kelly Keilwitz, Whidbey Sun Wind ke...@whidbeysunwind.com wrote: Hi All, I'm working on the design for a PV Wind power system for a military installation. The specs call for Lightning Protection as follows: Provide a complete lightning protection system with a UL Lightning Protection Inspection Certificate. including, but not necessarily limited to, strike termination devices, conductors, ground terminals, interconnecting conductors, surge suppression devices, and other connectors and fittings required for a complete and usable system. Anyone have an idea of what qualifies? Is there a package product that has the UL Lightning Protection Inspection Certificate? Thanks, -Kelly Kelly Keilwitz, P.E. Whidbey Sun Wind Renewable Energy Systems NABCEP Certified PV Installer ke...@whidbeysunwind.com 360.678.7131 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Congested Panel Problem
Peter, You can address the inspector's first complaint by pointing to the new language (NEC 2008) in 690.64(B)(2): In systems with panelboards connected in series, the rating of the first overcurrent protection device directly connected to the output of a utility-interactive inverter(s) shall be used in the calculations for all busbars and conductors. This states that only the 20A breaker should be counted, the breaker directly connected to the inverter. Even if the AHJ has not adopted the 2008 Code, you may be able to get this accepted. This change to the Code is basically intended to eliminate confusion in the earlier cycles. BTW: what 20A breaker did you find that was rated for continuous duty? Best, David On 7/26/10 2:18 PM, Peter Parrish peter.parr...@calsolareng.com wrote: We occasionally run into a dual headache: a congested AND underpowered service panel. Case in point a 100A Zinsco main panel with no room for a two pole breaker for inverter back feed. Normally we pull two 20A/120V branch circuits out of the main panel into a subpanel, back feed the subpanel with the inverter output and feed the main panel from the subpanel. The inverter in question is a SMA SB4000. Minimum over current protection is 16.66A (e.g. 20A continuous duty breaker). Otherwise protection needs to be 20.83A (e.g. 25A regular breaker). So we installed a 100A subpanel, pulled in the two 20A circuits, backed this subpanel with the inverter via a 20A continuous duty breaker, and fed the main panel via #8 wire and a 40A breaker. The inspector has a problem with this approach. Doesn't have a problem with the 20A breaker in the subpanel, but he objects to the 40A breaker in the main panel. His reasoning includes applying NEC 790.64(B). I believe the last sentence of (B)(2) stipulates that the breaker back feeding the subpanel is the one that counts, not what eventually what breaker back feeds the main panel. This inspector also has a problem with the production meter we installed. He wanted to see the UL Listing on the meter. I called Austin International (our vendor) about the meter in question (Itron Centron C1S) and they said that UL doest test meters as they (normally) are not used on the customer side of the service. Is there another listing for meters that would satisfy a nit-picky inspector? To make matters worse, we now have in stock both Itron Centron C1S meters as well as Schlumberger Centron C1S meters. Did Schlumberger buy out Itron? Or vice versa? Any help on the main panel calculation and acceptable listings for meter would be greatly appreciated. Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] #10 THWN-2
Mick, THWN-2 is 90°C rated per Table 310.16. This is key for conductors in conduit on a roof. On a roof in full sun ambient temperatures are such that a 75°C rated conductor will have a severely diminished allowable ampacity, if any allowable ampacity. Jollily, David On 7/23/10 11:52 AM, Mick Abraham m...@abrahamsolar.com wrote: I'm sorry to broadcast my ignorance, but: Could someone explain to me the significance of the -2 marking? Reply off-list if you wish to save bandwidth...but other List members may also be wondering... Thanks, Mick Abraham, Proprietor www.abrahamsolar.com http://www.abrahamsolar.com Voice: 970-731-4675 On Fri, Jul 23, 2010 at 10:48 AM, Nick Soleil nicksoleilso...@yahoo.com wrote: I have specified THWN-2 for years, but occasionally will not be able to source it! Sent from my iPhone On Jul 23, 2010, at 11:37 AM, Peter Parrish peter.parr...@calsolareng.com wrote: We went through a similar problem with some beach communities here in SoCal. Because of the high humidity (all winter and summer mornings) they wanted THWN-2 for all conduit runs (as well as PVC instead of EMT). At first we were charged a premium for THWN-2 compared to THHN. But then we found a source at All Phase Electrical Supply Burbank CA (a part of CED) for THWN-2 #10 stranded @ $162.40/k-ft. Brand is En(m?)core Wire. THWN-2 listing is printed on the insulation. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 mailto:peter.parr...@calsolareng.com peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 ___ List sponsored by Home Power magazine List Address: mailto:RE-wrenches@lists.re-wrenches.org RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] #10 THWN-2
Marco, The #10 THWN wire that your local suppliers carry may be cross-listed as THWN-2. My understanding is that it is not uncommon for smaller gauge wire to carry more listings than are printed on its insulation. (If that¹s not true, we¹ll find out shortly from someone on the list.) If your local supplier can¹t confirm this cross-listing for you, I¹d try tracing back to ask their supplier or the manufacturer. David Brearley, Senior Technical Editor SolarPro magazine On 7/23/10 12:52 AM, Marco Mangelsdorf ma...@pvthawaii.com wrote: Finding that wire in these here parts is pretty much impossible. Can any of my CA. brethren/sistren provide me any leads on wholesalers in either northern or southern CA. that carry #10 THWN-2 wire? Thanks, marco ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] AC wiring loss on micro-inverters
Maybe Marv can help out here. I¹ve talked with tech support at Enphase and am under the impression that you can center tap their branch circuits to reduce voltage drop. This technique was used on a project that we profiled in SolarPro: http://solarprofessional.com/article/?file=SP3_2_pg92_Projects_1search= David Brearley, Senior Technical Editor SolarPro magazine On 6/11/10 2:50 PM, Nick Soleil nicksoleilso...@yahoo.com wrote: Did you notice that in my calculation I divided the total amperage by 2 to get the average ampacity across the string. This seems to be the best way to deal with that. Otherwise the loss would have been over 2.8% Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax:707-769-9037 From: ma...@berkeleysolar.com ma...@berkeleysolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Fri, June 11, 2010 7:02:00 AM Subject: Re: [RE-wrenches] AC wiring loss on micro-inverters Nick, Good to see other wrenches looking at this issue. However, remember that in the interconnect cable between the last and the second to last Enphase, the current is small. If you really want to see how the loss is adding up you need a more detailed analysis that averages the voltage drop for the entire system of interconnect cables. Mark Frye Berkeley solar Electric Systems Hello wrenches and Marv: How many Enphase inverters do you put on a single parallel string? The Enphase manual allows for up to 15, but I have found that a single string of 15 can have very high voltage rise on the AC wiring. Up to 1.5% loss just on the Enphase cables, and that does not take into account resistance at the plug connectors or any home-run wiring. 15 inverters x 190 watts = 2850 watts 2850 watts / 240 Volts = 11.875 Amps (however at the beginning of the string it is 0 Amps) Average Amps on the Enphase cables is 11.875 / 2 = 5.9375 Amps length of contacts + internal wiring = ~6' Total Enphase cabling length (6' x 15 inverters) = ~90' 5.9375 Amps @ 240 V running 90' on #14 AWG CU = 1.4% loss It is pretty hard to design for 1.5% voltage drop if you have to size for 0% loss on your wiring! I hope Enphase will increase the size of the wire in their cables soon. Have you experienced issues with micro-inverters shutting off due to high AC voltages? Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax:707-769-9037 From: i2p i...@aol.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thu, June 10, 2010 4:50:47 PM Subject: Re: [RE-wrenches] Real world PV production On Jun 10, 2010, at 7:57:53 AM, Kelly Keilwitz, Whidbey Sun Wind ke...@whidbeysunwind.com wrote: PV Watts VASTLY underestimate PV production in our area. PV Watts underestimates in Central Ca too. Don ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Astopower 120 failure
Carl, Here's an excerpt from a news release that went out in late-December: Motech Industries Inc. (6244. TW) has signed an agreement to acquire GE Energy¹s (NYSE: GE) Delaware solar module assembly operation. The plant, which is located in Newark, Delaware assembles crystalline silicon based photovoltaic modules and currently employs 75 people. Financial terms were not disclosed. With the acquisition, Motech will be granted the rights to use GE Energy¹s module trademark for two years. In addition, Motech will assume the responsibility to provide warranty services to GE¹s existing module clients. Motech has been a supplier of solar cells to GE Energy for the past four years. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 6/8/10 10:13 AM, Carl Hansen solar...@cybermesa.com wrote: I have a warrantee issue with an Astropower 120, from what I've read it seems GE bought them out. Does anyone have contact info at hand for GE ? The panel is showing two burn marks on the backing at the point of two adjacent solder joints on one cell. Carl, HansenSun Electric ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] FSEC Approval Required for Permit?
Jason, I'm only familiar with this because a distributor I worked for went through the process of having their PV kits approved by FSEC. This was 6 years ago, so the requirement has been around for a while. This prerequisite never really made sense to me, for precisely the reason you point out. Changes in both market conditions and product lines means that the designs we use are constantly changing, plus roofs vary. I was never big on the kit concept for this very reason. But I suppose kits make a lot of sense if some central authority has to pre-approve an entire bill of materials. Microinverters are great for kits. If you're going to send per microinverter applications to FSEC, don't forget to send applications for every module you work with. In fact, send applications for every Enphase-compatible module. That'll keep them busy. Since the manufacturers revise their specs every year, you can send the whole package back to FSEC in another 12 months. (FSEC recently had a 2-year backlog to certify solar thermal collectors, so it could be worse.) The recommendation to engage SolarTech is a good one. Their goal is to remove unnecessary market barriers. You might also want to join you're state SEIA chapter and work to develop and implement more scalable quality control measures for the PV industry, jurisdictions and inspectors in Florida. I understand that there is a centralized body of knowledge at FSEC, but arguably a decentralized review process will better serve everyone in the long run. Best, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 6/3/10 8:57 AM, Jason Szumlanski ja...@fafcosolar.com wrote: Hi Wrenches, Has anyone dealt with a jurisdiction that requires FSEC or similar system approval as a prerequisite for obtaining a PV permit? Although we have installed many systems in a particular jurisdiction in our area, they just rejected a permit application because we do not have an FSEC system certification on this system (24 Enphase microinverters). We are having a hard time getting them to explain from where the requirement came. It seems like a nonsense roadblock to me. I can't imagine what purpose an FSEC certification would serve in the case of microinverters. As long as you are using a module on Enphase's compatibility list and the module itself has FSEC certification, can you think of any logical reason to jump through this hoop? On that note, I contacted FSEC to see what it would require to certify Enphase microinverter systems. They are telling me that we would have to apply for one system, and then apply for similar systems if the number of inverters changes. That doesn't make any sense to me. Are we supposed to submit applications for 1, 2, 3...50...150 module systems? I doubt they have time to deal with the paperwork for hundreds of similar system applications. Imagine dropping 200 similar system applications in their inbox to cover all quantities of microinverters. Jason Szumlanski Fafco Solar Cape Coral, FL ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string?
In the same issue of SolarPro as the “Optimal PV-to-Inverter” Sizing Ratio” article (April/May 2010), the lead article is “Production Modeling for Grid-Tied PV Systems” by Tarn Yates and Bradley Hibberd at Borrego Solar: http://solarprofessional.com/article/?file=SP3_3_pg30_Yates While your question below can’t be answered using PVWatts, it can be answered using the Solar Advisor Model (SAM), which was developed by NREL and Sandia w/ DOE funding. SAM is available for free download here: www.nrel.gov/analysis/sam/ David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/19/10 6:40 PM, Jim MacDonald j...@solaresystems.com wrote: SB8000US only good for 480 Vac, we’re tying in at 208. 11 strings has been calc’d to be OK (600vdc) for record low -4 fahrenheit (-20 celsius). I think the big concern as mentioned is getting the Voc high early in the AM to wake the inverter up, also maintaining the Vmp later in the day to keep it running for as long as possible into the late afternoon/ evening. Will those extra kWh gleaned in the early AM/ late PM over the course of 365 days be more than the kWh clipped during peak production times with the 9.075 kWdc? NYC average summer highs between 79 and 84 fahrenheit early june-late august.? Sunlink rack @ 10° on a silver-painted built-up roof. Time-of-use utility $ peak-shaving is not an issue here. Thank you From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Darryl Thayer Sent: Monday, April 19, 2010 5:58 PM To: RE-wrenches Subject: Re: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string? The temperature correction is the concern. I have heard lots of stories of inverters dieing when it gets to cold. Look in the code book 690.7 at the temperature correction table. Go to weather.com and find your record low temperature. Find you Tc factor and will your senerios work? I have heard from a sunny boy rep that it is OK to over power by 1.25% darryl --- On Mon, 4/19/10, Dana d...@solarwork.com wrote: From: Dana d...@solarwork.com Subject: Re: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string? To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Date: Monday, April 19, 2010, 4:31 PM Many times we switch to another module manufacturer as one will not fit or another inverter manufacturer. PVPowered has a more relaxed window and we have had fine success with them when SMA does not fit. Cold is the dictator and the 600 VDC threshold. Thanks, Dana Orzel Great Solar Works, Inc web - www.solarwork.com E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 We have been slow to give up on the myth of the Earth's generosity. Rather grandly, we have overdrawn our accounts. Barbara Kingsolver - Water is life. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jim MacDonald Sent: Monday, April 19, 2010 2:37 PM To: RE-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string? For a straight grid-tie system@ 10 degree tilt, 180 azimuth, zero/little shade, NYC avg 4.29 kWh/m²/day. Feed an SMA7000 with (3) strings of 11 Suntech STP275’s [9.075 kWdc] Or Do strings of 10, so itd be 8.250 kWdc into the 7 kWac inverter. Strings of 11= 491.7 Voc; 386 Vmp Strings of 10= 447 Voc; 351 VmpThe tradeoff would be power clipping at/around noon in the sunny months in the 9.075 kW scenario; Inverter sleeping late every morning and retiring early in the evenings in the lowered voltage scenario. Trying to figure out which would yield more kWh at the end of the year. Any ideas appreciated, thanks Jim MacDonald Solar Energy Systems, LLC Brooklyn, NY 11222 www.solarEsystems.com http://www.solaresystems.com/No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2819 - Release Date: 04/19/10 00:31:00 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] prof liabilty insurance
SEIA has on offician insurance broker: David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/20/10 4:35 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: I¹m in search for an insurance co. that provides professional liability insurance (also known as an errors and omissions policy) for PV integrators. That is, do any of you know of any particular insurance companies out there that actually have a clue about our trade instead of trying to shoe horn us into some other contracting or engineering profession category on their lame-brain forms? You¹d think that by now some insurance companies would specifically list solar electric contractors as a separate categorythen again few members of the public are able to grasp the difference between a kW and kWh. Thanks, marco Marco Mangelsdorf, President 69 Railroad Avenue, A-7 Hilo, Hawai'i 96720 (808) 969-3281, 934-7462 facsimile www.provision-solar.com http://www.provisiontechnologies.com image.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] prof liabilty insurance
SEIA has an official insurance broker: www.kessleradvisors.com/contentnt.aspx?id=212 David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/20/10 4:35 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: I¹m in search for an insurance co. that provides professional liability insurance (also known as an errors and omissions policy) for PV integrators. That is, do any of you know of any particular insurance companies out there that actually have a clue about our trade instead of trying to shoe horn us into some other contracting or engineering profession category on their lame-brain forms? You¹d think that by now some insurance companies would specifically list solar electric contractors as a separate categorythen again few members of the public are able to grasp the difference between a kW and kWh. Thanks, marco Marco Mangelsdorf, President 69 Railroad Avenue, A-7 Hilo, Hawai'i 96720 (808) 969-3281, 934-7462 facsimile www.provision-solar.com http://www.provisiontechnologies.com David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) image.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string?
Is using the SMA SB 8000US out of the question? http://www.sma-america.com/en/products/solar-inverters/sunny-boy/sunny-boy-5 000us-6000us-7000us-8000us.html On 4/19/10 3:37 PM, Jim MacDonald j...@solaresystems.com wrote: For a straight grid-tie system@ 10 degree tilt, 180 azimuth, zero/little shade, NYC avg 4.29 kWh/m²/day. Feed an SMA7000 with (3) strings of 11 Suntech STP275¹s [9.075 kWdc] Or Do strings of 10, so itd be 8.250 kWdc into the 7 kWac inverter. Strings of 11= 491.7 Voc; 386 Vmp Strings of 10= 447 Voc; 351 Vmp The tradeoff would be power clipping at/around noon in the sunny months in the 9.075 kW scenario; Inverter sleeping late every morning and retiring early in the evenings in the lowered voltage scenario. Trying to figure out which would yield more kWh at the end of the year. Any ideas appreciated, thanks Jim MacDonald Solar Energy Systems, LLC Brooklyn, NY 11222 www.solarEsystems.com http://www.solaresystems.com/ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Irradiance data
You might check in with the monitoring companies you work with to see if they can pull up the data from one of your sites with an irradiance meter. You might already have this in an admin view. If not, maybe someone on this list does. NREL or Sandia may also collect this data on an ongoing basis. While I¹m not sure who you¹d contact, there are extensive resources listed at the end of the Production Modeling article in SolarPro. That issue will post online this week start mailing very soon. I also suspect 3TIER has the data you want (http://www.3tier.com/en/), but I¹m not sure they¹d give it away. Since you¹re not planning on making money with the data, maybe they¹ll share. Doesn¹t hurt to ask... On 3/3/10 12:57 PM, Andrew Truitt atru...@gmail.com wrote: David - Thanks! This is great as an average for comparison. Any thoughts on where I could get data specifically from 2009 or the last couple of months? On Wed, Mar 3, 2010 at 10:52 AM, David Brearley david.brear...@solarprofessional.com wrote: Look for a super comprehensive article on the topic of production modeling in the Apr/May issue of SolarPro (SP3.3) by Tarn Yates and Bradley Hibberd of Borrego Solar. It includes information on TMY (typical meteorological year) data, like that published by NREL here: http://rredc.nrel.gov/solar/pubs/redbook/ David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com http://david.brear...@solarprofessional.com On 3/3/10 9:35 AM, Andrew Truitt atru...@gmail.com http://atru...@gmail.com wrote: Is anyone aware of a resource for finding local historical irradiance data? We've had a cloudy winter around the DC Metro area and I would like to quantify how far down we are from the average for new customers concerned with production. Thanks in advance, Drew ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] tyco connector tool
Jay, You might want to consider a multi-purpose tool: http://solarprofessional.com/article/?file=SP2_3_pg20_TheWire_5search= Best, David On 2/13/10 4:57 PM, jay peltz j...@asis.com wrote: I'm in the market for a Tyco connector tool . (I already have the MC tool) Any recommendations ? thanks, jay peltz power ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] kwh meters
Is it a Form 12-S meter? If not, that¹s the reason its not working. Here¹s an article you can refer to: http://solarprofessional.com/article/?file=SP1_1_pg16_QandA_3search= David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 1/28/10 2:57 PM, g...@arp-solar.com g...@arp-solar.com wrote: I am using an analog GE kwh meter on an outback system with battery backup to a protected loads panel. The AC in to the inverter is attached to the bottom of one leg of the meter and the AC out of the inverter is connected to the top of the other leg. This should give me an accurate record of just the production from the system. The idea is that the AC IN that will power the protected loads panel at night will come in the bottom of one leg and turn the meter backwards then exit through the top of the meter going forward thus cancelling those kwh. out. I have a neutral hooked to the meter because I am using it to record 120V but I am not getting accurate readings with this configuration. Any suggestions on metering in this case? I need a utility grade kwh meter. Gary Easton NABCEP Certified Solar PV NABCEP Certified Solar Thermal APPALACHIAN RENEWABLE POWER LTD. Stewart, Ohio 740-277-8498 ³I'd put my money on solar energy I hope we don't have to wait 'til oil and coal run out before we tackle that.² Thomas Edison, in conversation with Henry Ford and Harvey Firestone, March 1931 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Square D DC disconnects
Thanks, Bill. Glad to hear you think the HU series is still a good option. When I was making the rounds at SPI, I stopped by the Eaton booth and got the sense that they were gunning for Square D. They made light of Square D¹s self-certification of the HU series discos. The rep also made a statement about the new Eaton dc discos being the only ones designed to meet UL1741 requirements. When I got home, the first thing I looked up was 690.4(D). This doesn¹t say anything about dc disconnects needing to be listed to some special PV standard. Is there a movement in this direction? Is there a UL1741 standard for dc discos that is somehow different that the standard used for other dc disconnects? Best, David On 1/11/10 5:28 PM, Bill Brooks billbroo...@yahoo.com wrote: David and Kirpal, It is ultimately up to the AHJ whether or not they accept the Schneider/Square D self certification. That is a judgment call the installer needs to clear with the AHJ. That being said, having Square D behind the rating of a switch is a whole lot more than any one of the smaller companies making equipment for the PV industry. I will continue to use the 30, 60, and 100-amp versions in the way recommended by the manufacturer because it is a huge saving in cost and they are well made switches. I will also check with the local AHJ before installing them in case they are not going to pass it. You have to remember you are working with one of the largest electrical suppliers in the world. They have a huge reputation with local jurisdictions. Eaton has been in the process of trying to make a big deal out of this issue since they want a piece of the market. Fortunately, they are starting to build products specifically for the PV industry, which I applaud. However, they need to be given a hard time for the way they have tried to imply that all Square D switches are not properly listed. They won¹t admit to that because they would end up in a legal battle, but that is essentially what they have been doing. Square D still has the largest selection of dc-rated equipment on the market. Eaton has a long way to go. In a recent project that I reviewed, the engineer pulled the Square D 400-amp disconnect and replaced it with an Eaton disconnect at the insistence of the Eaton rep. The Eaton product was not properly rated or listed for the voltage while the Square D product was. This is the insanity that needs to stop. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, January 11, 2010 11:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] Square D DC disconnects Kirpal, Have you checked out the SolarBOS disconnecting combiners? Their 28A version might be ideal for large resi or small commercial applications. For larger projects, Blue Oak PV Products and AMtec Solar also have disconnecting combiners. Thanks for sharing the updated Square D tech note. I had no idea that the Square D HU Series disconnects were not UL-listed when used as described in the older tech notes. The fact that this is not a UL-listed use of the heavy duty safety switch, pretty much means that it is not an option for integrators. As far as I know, there is no other product that is listed for this use. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com On 1/9/10 4:14 PM, Kirpal Khalsa solarwo...@gmail.com wrote: Hi All.. I recently came across a revised technical bulletin from square D ( http://ecatalog.squared.com/pubs/Electrical%20Distribution/Safety%20Switches/H eavy%20Duty/3110DB0401.pdf )..we have for years been using the Square D DC Disconnect of various amperages (30, 60, 100) as disconnects leading upto the inverter from the array.we have frequently wired one string to each of the three poles of the disconnect..we have had this configuration inspected by inspectors regularly with approval everytime..this new revision of the document from Square D shows this is no longer a UL listed method.they are now stating in this document that they are self certifying this technique...have any of you come across this or know why Square D has back tracked? Something else I noticed is that they have raised the amperage rating on the 30A disconncect per pole by 2 amps from 18 to 20 which is good especially when using higher amperage modules like Evergreen ES-A series which would not have ben allowed to use the 30A disconnect as the short circuit current rating was too high for the derated poles. This is not a huge concern as more and more of the inverters we are using these days have an appropriate disconnect included with the inverter negating the need for an additional stand alone disconnect. On a side noteAre there any other manufacturers making listed muiti
Re: [RE-wrenches] Square D DC disconnects
Right, Kent, but 690.4(D) does require the use of products ³identified and listed for the application.² So, for example, UL-listed combiner boxes are required per NEC 2008, whereas integrators could previously site build combiners using UL-listed parts. The appropriate listing for a PV combiner, everyone agrees, is UL1741. This code article lists most major components in a PV system, but not discos. I¹m simply wondering if there is some activity I am unaware of seeking to add dc discos to this list or to the UL1741 standard. Just curious. On 1/11/10 6:27 PM, Kent Osterberg k...@coveoregon.com wrote: David, The NEC doesn't require UL listing. The most appropriate section of the code about this is Article 110, Requirements for Electrical Installations, it requires equipment to be approved. In many jurisdictions, such as Oregon, that means evaluated and approved by a testing lab such as UL. Kent Osterberg Blue Mountain Solar, Inc. David Brearley wrote: Re: [RE-wrenches] Square D DC disconnects Thanks, Bill. Glad to hear you think the HU series is still a good option. When I was making the rounds at SPI, I stopped by the Eaton booth and got the sense that they were gunning for Square D. They made light of Square D¹s self-certification of the HU series discos. The rep also made a statement about the new Eaton dc discos being the only ones designed to meet UL1741 requirements. When I got home, the first thing I looked up was 690.4(D). This doesn¹t say anything about dc disconnects needing to be listed to some special PV standard. Is there a movement in this direction? Is there a UL1741 standard for dc discos that is somehow different that the standard used for other dc disconnects? Best, David On 1/11/10 5:28 PM, Bill Brooks billbroo...@yahoo.com wrote: David and Kirpal, It is ultimately up to the AHJ whether or not they accept the Schneider/Square D self certification. That is a judgment call the installer needs to clear with the AHJ. That being said, having Square D behind the rating of a switch is a whole lot more than any one of the smaller companies making equipment for the PV industry. I will continue to use the 30, 60, and 100-amp versions in the way recommended by the manufacturer because it is a huge saving in cost and they are well made switches. I will also check with the local AHJ before installing them in case they are not going to pass it. You have to remember you are working with one of the largest electrical suppliers in the world. They have a huge reputation with local jurisdictions. Eaton has been in the process of trying to make a big deal out of this issue since they want a piece of the market. Fortunately, they are starting to build products specifically for the PV industry, which I applaud. However, they need to be given a hard time for the way they have tried to imply that all Square D switches are not properly listed. They won¹t admit to that because they would end up in a legal battle, but that is essentially what they have been doing. Square D still has the largest selection of dc-rated equipment on the market. Eaton has a long way to go. In a recent project that I reviewed, the engineer pulled the Square D 400-amp disconnect and replaced it with an Eaton disconnect at the insistence of the Eaton rep. The Eaton product was not properly rated or listed for the voltage while the Square D product was. This is the insanity that needs to stop. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, January 11, 2010 11:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] Square D DC disconnects Kirpal, Have you checked out the SolarBOS disconnecting combiners? Their 28A version might be ideal for large resi or small commercial applications. For larger projects, Blue Oak PV Products and AMtec Solar also have disconnecting combiners. Thanks for sharing the updated Square D tech note. I had no idea that the Square D HU Series disconnects were not UL-listed when used as described in the older tech notes. The fact that this is not a UL-listed use of the heavy duty safety switch, pretty much means that it is not an option for integrators. As far as I know, there is no other product that is listed for this use. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com On 1/9/10 4:14 PM, Kirpal Khalsa solarwo...@gmail.com wrote: Hi All.. I recently came across a revised technical bulletin from square D ( http://ecatalog.squared.com/pubs/Electrical%20Distribution/Safety%20Switches /Heavy%20Duty/3110DB0401.pdf )..we have for years been using the Square D DC Disconnect of various amperages (30, 60, 100) as disconnects leading upto the inverter from the array.we
Re: [RE-wrenches] Square D DC disconnects
Thanks for the clarification, Bill. If they add this to UL1741, I hope they will do so in a manner that recognizes the unique characteristics of PV applications. Definitely easier to interrupt a 10A source than a 10,000A one. On 1/11/10 6:43 PM, Bill Brooks billbroo...@yahoo.com wrote: David, The state by the Eaton guy at SPI shows that person¹s lack of understanding. The person I talked to was adamant that all disconnects had to be tested to the disconnect standard that assumes a high (10,000-amp) current source behind any fault. Switch openings are also tested based on the inductance in the circuit since that has a major impact on the size and duration of the arcespecially in ac systems. Square D did an evaluation based on the limited fault currents and inductance in PV system circuit that has no batteries. I believe their evaluation is valid. The issue is that there is no specific test at UL yetthat¹s why UL did not list it (I¹m pretty sure they were involved at some level, but that is impossible to prove). It will probably be added to UL1741. Perhaps that was what the Eaton rep was referringwe¹ll give him the benefit of the doubt. I still use my basic rule similar to the rule for politicianshow do you know if a marketing guy is lying?== his lips are moving. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, January 11, 2010 3:41 PM To: RE-wrenches Cc: 'Tim Townsend' Subject: Re: [RE-wrenches] Square D DC disconnects Thanks, Bill. Glad to hear you think the HU series is still a good option. When I was making the rounds at SPI, I stopped by the Eaton booth and got the sense that they were gunning for Square D. They made light of Square D¹s self-certification of the HU series discos. The rep also made a statement about the new Eaton dc discos being the only ones designed to meet UL1741 requirements. When I got home, the first thing I looked up was 690.4(D). This doesn¹t say anything about dc disconnects needing to be listed to some special PV standard. Is there a movement in this direction? Is there a UL1741 standard for dc discos that is somehow different that the standard used for other dc disconnects? Best, David On 1/11/10 5:28 PM, Bill Brooks billbroo...@yahoo.com wrote: David and Kirpal, It is ultimately up to the AHJ whether or not they accept the Schneider/Square D self certification. That is a judgment call the installer needs to clear with the AHJ. That being said, having Square D behind the rating of a switch is a whole lot more than any one of the smaller companies making equipment for the PV industry. I will continue to use the 30, 60, and 100-amp versions in the way recommended by the manufacturer because it is a huge saving in cost and they are well made switches. I will also check with the local AHJ before installing them in case they are not going to pass it. You have to remember you are working with one of the largest electrical suppliers in the world. They have a huge reputation with local jurisdictions. Eaton has been in the process of trying to make a big deal out of this issue since they want a piece of the market. Fortunately, they are starting to build products specifically for the PV industry, which I applaud. However, they need to be given a hard time for the way they have tried to imply that all Square D switches are not properly listed. They won¹t admit to that because they would end up in a legal battle, but that is essentially what they have been doing. Square D still has the largest selection of dc-rated equipment on the market. Eaton has a long way to go. In a recent project that I reviewed, the engineer pulled the Square D 400-amp disconnect and replaced it with an Eaton disconnect at the insistence of the Eaton rep. The Eaton product was not properly rated or listed for the voltage while the Square D product was. This is the insanity that needs to stop. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David Brearley Sent: Monday, January 11, 2010 11:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] Square D DC disconnects Kirpal, Have you checked out the SolarBOS disconnecting combiners? Their 28A version might be ideal for large resi or small commercial applications. For larger projects, Blue Oak PV Products and AMtec Solar also have disconnecting combiners. Thanks for sharing the updated Square D tech note. I had no idea that the Square D HU Series disconnects were not UL-listed when used as described in the older tech notes. The fact that this is not a UL-listed use of the heavy duty safety switch, pretty much means that it is not an option for integrators. As far as I know, there is no other product that is listed for this use. David Brearley, Senior
Re: [RE-wrenches] Best angle - direct grid tie
Great format for an integrator and its staff. Thanks for sharing, Mike. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com On 1/7/10 1:26 PM, Michael Kelly m...@solarflair.com wrote: Drake, I did an analysis for optimum conditions based on tilt and azimuth a while ago for our area around Boston. I did it in such a way as any combination of tilt and azimuth gives you % of optimum conditions. See attached. All of the data was from PVWatts simulations. Maybe you can make one for your area when you have some free time. - Mike -- Michael Kelly Project Manager / Project Engineer NABCEP Certified Solar PV Installer SolarFlair Energy, Inc. 11 Mayhew Street Framingham, MA 01702 Direct Mobile: 617-899-9840 Main Phone: 508-293-4293 Main Fax: 508-293-4003 m...@solarflair.com On Wed, Jan 6, 2010 at 9:48 AM, Drake Chamberlin drake.chamber...@redwoodalliance.org wrote: Thanks for all of the excellent advice regarding the best tilt angle. It is a real privilege to be a part of, and have access to the incredible resource of the knowledge and experience represented by this list. It looks like a 30 degree angle will work fine for 39 degrees N. This corresponds well with the Unirac U-LA, pre engineered designs. Drake Drake Chamberlin Athens Electric OH License 44810 CO License 3773 NABCEP TM Certified PV Installer Office - 740-448-7328 Mobile - 740-856-9648 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Fronius IG Plus line
Marco, They are all single-phase, with the exception of the IG Plus 11.4-3 and 12.0-3, which are 3-phase units. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) On 12/17/09 5:55 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: I have yet to install a Fronius IG Plus inverter. Looking through the manual I¹m trying to determine whether each inverter in the line, between 3 and 12 kW, puts out three-phase power across all three poles, L1, L2 and L3 or whether all or some of these models put out power across just one or two poles like the SMA Sunny Boys. I¹d appreciate any education on this. Thanks, marco Marco Mangelsdorf, President 69 Railroad Avenue, A-7 Hilo, Hawai'i 96720 (808) 969-3281, 934-7462 facsimile www.provision-solar.com http://www.provisiontechnologies.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org image.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] whos doing the PV testing
Jay, According to Pat Saxon at the California Energy Commission, the list of approved test facilities currently include: CSA, Intertek (ETL) and UL. TUV Rheinland of North America is in the process of expanding their scope to include this testing. The testing performed includes portions, but not all, of IEC 61215 (for c-SI) and IEC 61646 (for thin film). The nominal operating cell temperature (NOCT) and the temperature coefficient of power measurements reported from these third party testing laboratories are now used to derive the PTC ratings for CEC eligible modules. That¹s basically the change; previously these values were self-reported by the manufacturers, generally optimistically. A section in one of our feature articles, a recent QA response and a letter in our Mail department cover aspects of the new testing. If you would like me to send you links or PDFs to these sources just contact me offline. Best regards, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) On 9/29/09 10:30 PM, jay peltz j...@asis.com wrote: HI All, Im wondering if anyone knows who is doing the new 3rd party PV testing for california? And also how they are doing it, ie real world testing or modeling. thanks, jay peltz power ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] whos doing the PV testing
Yes, the 3rd-part labs determine the temp coefficients. From the ³PV Module Eligibility Procedure² PDF on gosolarcalifornia.org: ³The process for adding PV modules to the SB1 list is as follows: 1. The manufacturer gets their product certified to UL 1703. UL, CSA, and Inte rtek are the NRTLs who can currently perform this testing. 2. The manufacturer gets additional performance parameter testing completed by an ILAC-affiliated laboratory as listed above. Detailed information on the tes ts can be found on the equipment request form in Step 3. The additional performance p arameter testing required is shown below: Crystalline modules IEC 61215 Sections: 10.2Maximum Power Determination 10.4Measurement of Temperature Coefficients 10.5Measurement of NOCT 10.6Performance at STC and NOCT 10.7Performance at Low Irradiance 3. The manufacturer fills out the Energy Commission equipment application form, found here: http://gosolarcalifornia.org/equipment/documents/EQUIPMENT_REQUEST.DOC 4. The manufacturer emails a copy of the UL 1703 Certification Letter, the ILAC laboratory test report, and the Energy Commission equipment application form to Daria M ashnik. All documentation must be in English KEMA will reject any test reports tha t are not in English.² On 9/30/09 10:28 AM, jay peltz j...@asis.com wrote: Hi David, Yes I saw the piece in the new SolarPro. Do you know if they are also testing for temp derating, or are we still going to be using the manufacturers % loss's? thanks, jay peltz power On Sep 30, 2009, at 7:59 AM, David Brearley wrote: Jay, According to Pat Saxon at the California Energy Commission, the list of approved test facilities currently include: CSA, Intertek (ETL) and UL. TUV Rheinland of North America is in the process of expanding their scope to include this testing. The testing performed includes portions, but not all, of IEC 61215 (for c-SI) and IEC 61646 (for thin film). The nominal operating cell temperature (NOCT) and the temperature coefficient of power measurements reported from these third party testing laboratories are now used to derive the PTC ratings for CEC eligible modules. That¹s basically the change; previously these values were self-reported by the manufacturers, generally optimistically. A section in one of our feature articles, a recent QA response and a letter in our Mail department cover aspects of the new testing. If you would like me to send you links or PDFs to these sources just contact me offline. Best regards, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) On 9/29/09 10:30 PM, jay peltz j...@asis.com wrote: HI All, Im wondering if anyone knows who is doing the new 3rd party PV testing for california? And also how they are doing it, ie real world testing or modeling. thanks, jay peltz power ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] does the federal grant affect depreciation?
Dana, Here is an excerpt from the latest SEIA tax manual that supports the information from Randy: ³1.6.2 Basis ReductionThe owner of solar equipment on which an investment credit is claimed or on which a cash grant is paid by the Treasury can depreciate only 85 percent of the cost. The basis¹ for depreciation must be reduced by half the amount of the investment credit or cash grant.² Best regards, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer On 9/30/09 2:11 PM, Dana Brandt d...@ecotechenergy.com wrote: Thanks, Randy. Do you have a reference for the depreciable basis being reduced by half the tax credit? I've emailed the treasury dept. and will report back what I hear from them. Dana Dana Brandt Ecotech Energy Systems, LLC www.ecotechenergy.com http://www.ecotechenergy.com d...@ecotechenergy.com 360.510.0433 On Tue, Sep 29, 2009 at 8:39 PM, Randy ra...@positiveenergysolar.com wrote: Dana, Federal depreciation rules establish depreciation or the depreciable basis based on the system cost reduced by half of the tax credit. The federal grant is ³in lieu² of the tax credit therefore I am fairly certain that treatment should be the same as taking the tax credit. However, I couldn¹t readily find a definitive answer and it was not covered in the SEIA webinar. If you cant get an affirmative response then email the treasury department at 1603questi...@do.treas.gov. Randy Randy Sadewic Positive Energy Office: 505 424-1112 Cell: 505 570-0137 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Dana Brandt Sent: Tuesday, September 29, 2009 5:33 PM To: RE-wrenches Subject: [RE-wrenches] does the federal grant affect depreciation? Wrenches, I feel like this must have been discussed before, but I can't find it in the archives. If a business takes the 30% federal grant, do they get to depreciate 100% of the system cost, or just the remaining 70%? Thanks, Dana Dana Brandt Ecotech Energy Systems, LLC www.ecotechenergy.com http://www.ecotechenergy.com d...@ecotechenergy.com 360.510.0433 ___ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Pitched EPDM Roof Attachment
That¹s what came to my mind, as well, based on the description. David Brearley, Senior Technical Editor SolarPro magazine On 9/9/09 7:14 PM, North Texas Renewable Energy Inc nt...@earthlink.net wrote: Carl check out the Unirac Fast Foot. http://www.unirac.com/pdf/fastfoot_install.pdf Jim Duncan North Texas Renewable Energy Inc 817.917.0527 nt...@earthlink.net www.ntrei.com *** - Original Message - From: Carl Adams swingjun...@gmail.com To: RE-wrenches@lists.re-wrenches.org Sent: Tuesday, September 08, 2009 3:04 PM Subject: [RE-wrenches] Pitched EPDM Roof Attachment Hello Wrenches, I have a job on a 3.5/12 pitched rubber roof. We have 1.5² foam under the EPDM, then the steel decking, then the purlins. Purlin spacing supports adequate attachment points for a conventional rail mounted system. I have 2 questions 1) A typical L-foot attachment to the roof would likely compress the underlying foam and result in divets at each foot. What do you recommend to disperse the load at the point of attachment 2) What type of screw do you recommend for attaching the L-Feet to the purlins With Regards Carl Adams NABCEP Certified Solar PV Installer NABCEP Certified Solar Thermal Installer SunRock Solar Cincinnati, Ohio 513.766.6025 www.sunrocksolar.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] fed grant
No. The Recovery Act specifies that Buy America provisions are applicable to ³Division A² programs of the ARRA. The cash grant, according to a resource made available to SEIA members, is a ³Division B² program. David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) On 7/31/09 6:50 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: In order to get the 30 percent federal grant rather than the 30 percent ITC, is there any requirement that the equipment used be American made? Thanks, marco Marco Mangelsdorf, President 69 Railroad Avenue, A-7 Hilo, Hawai'i 96720 (808) 969-3281, 934-7462 facsimile www.provision-solar.com http://www.provisiontechnologies.com image.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Power Factor
Ron, Here is a definition for Power Factor that we used in our String Inverter guide in SP1.1: POWER FACTOR AT RATED OUTPUT Definition: The ratio of true power to apparent power in the inverter ac output circuit at its rated power. Importance: True power is measured in units of watts and describes the ability to do useful work. Apparent power includes both work-producing power and reactive power measured in volt-amperes. Power factor is a comparison of watts to volt-amperes or real power to apparent power in an ac circuit. If the power factor in a circuit is 1.0, then all of the power generated is available to do useful work. The point is that you can describe the power factor for an inverterit approaches unity (see the Table in SP1.1)but this does not apply for PV modules. You can simply write ³NA² in the space provided. If they ask why, the simplest explanation it that PV modules are part of a DC circuit and power factor applies to AC circuits. It¹s not at all uncommon for interconnection documents to request information that is not applicable to PV systems. Best, David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com (Sample copy available for download at: solarprofessional.com/sample) On 7/30/09 2:00 PM, Ron Young solarea...@solareagle.com wrote: Ok, so all seem to be in agreement more or less. How do I break it to British Columbia Hydro? :-| I think they must be misunderstanding what they are asking for but the question is in the section for PV and on the same line as the total output in Kwh of the PV. Power Factor % I'll contact them and see where this goes but I don't fully understand what power factor is which will make it hard to argue my case. My understanding is that it is the difference between what the utility supplies to a residence vs. the actual loads being used by that residence expressed as a percentage. I came across the following course offering by SEI that discusses Power Factor with reference to PV: POWER FACTOR AS IT RELATES TO SOLAR INSTALLATIONS Presented By: Michael Smith of Alpine Management Systems This session will deal with power factor: What is power factor? What causes low power factor? Why improve your power factor? This session will explain the role of power factor correction as it applies to solar installations. There are currently over 67,000 KVAR installations in 26 countries resulting in phenomenal energy savings with a corresponding reduction in greenhouse gas emissions. Session includes several KVAR installations and the resultant savings. http://www.solarenergy.org/workshops/docs/industry08_trainingdetails.pdf Ron On 30-Jul-09, at 7:43 AM, Wind-sun.com wrote: There is no such thing as a power factor for DC or for panels. . . Northern Arizona Wind Sun - Electricity From The Sun Since 1979 Solar Discussion Forum: http://www.wind-sun.com/ForumVB/ . . - Original Message - From: Ron Young mailto:solarea...@solareagle.com To: RE-wrenches mailto:re-wrenches@lists.re-wrenches.org Sent: Wednesday, July 29, 2009 5:45 PM Subject: [RE-wrenches] Power Factor Can anyone point me in the direction to find the power factor for Sanyo HIT N 205 panels? The utility is requesting it on a net metering interconnection application. Ron Young earthRight Products - Solareagle.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http
Re: [RE-wrenches] Line Side Feed In and Disconnects
This is a feed-in tariff program, not a net-metered program. So as long as the inverter output circuit is metered, no one is giving away any PV generated electricity. In fact, PV-generated energy is bought at $0.32/kWh: http://www.greentechmedia.com/articles/gainesville-to-launch-solar-feed-in-t ariff-5429.html From the utility¹s point of view, the line side connection makes lots of sense. Any generator that is separately meteredlike a 1MW gas fired turbine, for exampleis line side connected to the utility grid...on the utility side of any revenue meter. That is probably why the AHJ wants the separately metered PV system connected on the utility side of the meter. They are treating this like any other power plant that feeds the grid and is paid per kWh generated. On 3/10/09 10:48 PM, William Miller will...@millersolar.com wrote: Friends: I was not aware that the goal was to install the point of connection ahead of the meter. The section says: A photovoltaic power source shall be permitted to be connected to the supply side of the service disconnecting means...(emphasis added). The goal is to be down stream of the utility meter. Otherwise you are giving away your PV generated electricity. Granted this is not always easy, but most switch gear has provisions for a fire pump and this is the point where you connect. William Miller At 07:00 PM 3/10/2009, you wrote: I hope I can help. If he installs ahead of the meter (line side install) he is installing a new service. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] FW: Panel Fire
Allan, there are 4 modules pictured in the ³before² photo, not 8. The after photo show the ³good² modules, the ones that did not burn. This suggests there are 4 module each on two separate roof faces. Please have another look at the before picture and count the frames. In the before picture each 250 W mystery module is supported at 4 corners only. They are some sort of large format modules. Nothing I can find online matches these characteristics, especially the superstrate material. Please re-read the homeowner¹s account in these various postings as well. Sundiego indicates that the module superstrate is not glass, but some other material. Apparently it is a material that melts when exposed to flame. It sure isn¹t glass, that¹s pretty clear by the photos and the written account. This does not look like an elaborate hoax to me. It does look, as BB points out, like a potential crime scene, a fraud at the very least. Something was misrepresented to this customer. It¹s pretty apparent that these modules are not listed and identified for the application. The installation isn¹t vaguely appropriate. It¹s just dumb luckliterallythat the house didn¹t burn down. Clearly the narrator is unreliable, but I don¹t think it is malicious, just ignorance. The dude¹s a ³solar newbie² and his house caught on fire. That¹s what it looks like to me. David On 2/11/09 6:57 PM, Allan Sindelar al...@positiveenergysolar.com wrote: I guess I'm not the only one who's suspicious of this whole story. This came to me off list. Some of the post here doesn't jive - it's pretty clear there's no glass, and the blurry corner doesn't look it to me. -Original Message- From: I may be very wrong here and I don¹t mean to impugn anyone¹s integrity but don¹t forget that in this era of digital animation movies you can¹t always believe what you see in photo either. (I'm sure no one here has ever Photoshopped a photo to make it more presentable looking.) I couldn't help but notice that the bottom right corner of the photo was surprisingly blurry and indistinct. It is difficult to distinguish one thing from the next, when just a few feet away but out of the range of detail in the photo, things seemed to be much clearer. I¹ve never seen a photo look like that in reality. It¹s as if the roof and array have mysteriously melted together. Also, I have never seen tempered glass melt in a low temperature fire. If it were a high temperature fire the roof would not have survived. I think that a great deal of caution is warranted especially considering the lack of detail that the poster is giving about the panels, location, installer/supplier, existence of another array etc. --- On Wed, 2/11/09, Allan Sindelar al...@positiveenergysolar.com wrote: One detail I haven't heard mentioned yet and am curious about - the photo of the fire damage appears to show the corner of another west(?)-facing array. I find it curious that the system owner described a 2 kW system made up of eight 250W(!) modules, which are clearly visible in the topmost system photo. There's just a whole lot that doesn't jive in this whole story. Scary to me . ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] voltag drop
This seems more convenient than remembering the constants for copper and aluminum. Please note that I did not give the complete units for those in my previous email. The units for ³k² in those formulas is ohms/mil foot. On 12/8/08 6:48 PM, Michael Gullo [EMAIL PROTECTED] wrote: Marco, I use the following formulas: single-phase Vd = (I x L x R x 2)/1000 3-phaseVd = (1.73 x I x L x R)/1000 L = one-way length R = resistance of conductor from Table 8 (usually from uncoated copper ohm/kFT column) Mike Michael Gullo Solar Solutions LLC Marlton, NJ NABCEP Certified PV Installer [EMAIL PROTECTED] - Original Message - From: Marco mailto:[EMAIL PROTECTED] To: re-wrenches@lists.re-wrenches.org Sent: Monday, December 08, 2008 5:12 PM Subject: [RE-wrenches] voltag drop I feel kinda foolish in asking this.but when calculating voltage drop in a conductor over distance, do I use the one-way or round-trip distance? thanks, marco Marco Mangelsdorf, Ph.D., President Electrical Contractor License C-26351 69 Railroad Avenue, Suite A-7 Hilo, Hawaii 96720 USA (808) 969-3281, fax 934-7462 www.provisiontechnologies.com http://www.provisiontechnologies.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Technical Editor SolarPro magazine NABCEP Certified PV Installer [EMAIL PROTECTED] Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com image.jpg___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Square D 225A load center
It has an option for a factory-installed 200A main breaker. On 12/4/08 12:31 PM, Christopher Freitas [EMAIL PROTECTED] wrote: How does the 225 amp rating make it ideal for 60 amp breakers? 20% of 225 amps is 45 amps and even with ³rounding up² it only gets you to 50 amps. Christopher Christopher Freitas Director of Research and Development OutBack Power Systems, Inc. [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] Tel 360 435 6030 Cell 360 202 4239 19009 62nd Ave NE Arlington WA 98223 USA www.outbackpower.com http://www.outbackpower.com/ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Truitt Sent: Thursday, December 04, 2008 8:33 AM To: RE-wrenches Subject: [RE-wrenches] Square D 225A load center Greetings all! I heard that Square D makes a load center with a 225A buss bar and a 200A main breaker - ideal for installing 60A of solar interconnection breakers. Does anyone have a part number (or any other info) on this item? Thanks! Andrew Truitt Standard Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] system commissioning time frames
Kirpal, Back in 2005 when the rebates were first on the horizon, Austin Energy would voluntarilyat the request of customershold off placing their PV kWh meter until after January 1, 2006. The intent was to put off commissioning systems before the rebate was available. Best, David On 12/3/08 12:59 PM, Kirpal Khalsa [EMAIL PROTECTED] wrote: Greetings..we recently installed a solar pv system on a residential customer and it has been inspected by both the local electrical inspector and the state rebate authority and approved. Now that we have passed those inspections, the next phase of the process is having the utility company come out and install their new meter for net metering..I was wondering if anyone has a definitive answer as to what actually commissions the system? We are thinking of having the power company hold off until after the new year so that the customer can get the 2009 tax credits instead of the 2008 credits... The question is does the system get commissioned once it is inspected or once the power company gets the new meter installed so that the system can actually be turned on. Thanks for any advice...It actually could be worth its weight in gold!... Cheers, Kirpal Khalsa Renewable Energy Systems www.oregonsolarworks.com http://www.oregonsolarworks.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] system commissioning time frames
Correct, but w/out the PV meter the system could not be commissioned. For the customer, it created a paper trail helping to verify the commissioning date. On 12/3/08 1:32 PM, Joel Davidson [EMAIL PROTECTED] wrote: It is nice to have a good working relationship with the utility, but scheduling and placing meters are just part of the job, not commissioning. From: David Brearley [EMAIL PROTECTED] To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wednesday, December 3, 2008 11:19:11 AM Subject: Re: [RE-wrenches] system commissioning time frames Kirpal, Back in 2005 when the rebates were first on the horizon, Austin Energy would voluntarilyat the request of customershold off placing their PV kWh meter until after January 1, 2006. The intent was to put off commissioning systems before the rebate was available. Best, David On 12/3/08 12:59 PM, Kirpal Khalsa [EMAIL PROTECTED] wrote: Greetings..we recently installed a solar pv system on a residential customer and it has been inspected by both the local electrical inspector and the state rebate authority and approved. Now that we have passed those inspections, the next phase of the process is having the utility company come out and install their new meter for net metering..I was wondering if anyone has a definitive answer as to what actually commissions the system? We are thinking of having the power company hold off until after the new year so that the customer can get the 2009 tax credits instead of the 2008 credits... The question is does the system get commissioned once it is inspected or once the power company gets the new meter installed so that the system can actually be turned on. Thanks for any advice...It actually could be worth its weight in gold!... Cheers, Kirpal Khalsa Renewable Energy Systems www.oregonsolarworks.com http://www.oregonsolarworks.com/ http://www.oregonsolarworks.com http://www.oregonsolarworks.com/ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org David Brearley, Technical Editor SolarPro magazine NABCEP Certified PV Installer [EMAIL PROTECTED] Direct: 541.261.6545 Fax: 541.512.0343 Visit our Web site at solarprofessional.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
