Re: [RE-wrenches] Cable tray
Bill, Thank you for continuing to help adopt more practical and 'user friendly' code1 requirements. As Glen pointed out, [NEC 2011] 392.10(B)(1)(a) could pose a problem for some AHJ's - even though 690.31(B) allows PV wire in exposed outdoor locations (presumably not in cable tray). It is truly counter-intuitive that by efforting responsible wire-management and installing PV wire in cable tray it would somehow create a code violation unless it was at least 1/0, and that it would somehow be allowed in a residential application under the same 392.10? It is also interesting to note the definition of Supervised Industrial Installation2 in 240.2 and that all of those conditions are not met in most cases Just wanted to say again: Thanks for the forward progress! Mark 1 - I know, I know: user-friendly code is an oxymoron J 2 - I could not find a referenced definition of Industrial Establishments [NYLE LOGO SMALL] Mark Richardson mrichard...@newyorklightenergy.commailto:mrichard...@newyorklightenergy.com 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.orgmailto: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.orgmailto: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.htmhttp://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.orghttp://www.members.re-wrenches.org inline: image002.jpg___ 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] Remote SW control
A friend of mine has an old Xantrex SW 4024 installed in a less-than-accessible location. He's looking for one of their remote control and monitoring panels. If you have one of these kicking around, or know of one, please contact me off line. Many thanks, Hilton -- Hilton Dier III Renewable Energy Design Partner, Solar Gain LLC 453 East Hill Rd. Middlesex, VT 05602 ___ 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
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
Re: [RE-wrenches] GSCM-mini with Honda EM5000SX
Thanks all for the comments. I did not install the batteries, genny, Outback inverter, or Mate, just the GSCM and an RTS. I've given the homeowner a lot of advice along the way but did not touch the other installer's work. It was clear from the beginning that the homeowner knows nothing about off-grid power generation or battery maintenance and that the previous installer didn't bother with code compliance or educating the homeowner on how to operate his own system. Yes, it's one of those. I'm trying to keep my distance while still being available to answer questions. Thanks again guys! Eric Stikes SunHarvest - Original Message - From: William Miller To: RE-wrenches Sent: Monday, March 25, 2013 12:41 PM Subject: Re: [RE-wrenches] GSCM-mini with Honda EM5000SX Eric: The generator-based charging may impose higher currents into the batteries than either PV charging or inverter consumption, triggering the problem. Melted battery terminals are not uncommon. You must have washers under your bolt heads with lead flanges. Otherwise the bolt heads sink into the lead, loosening connections. All mating surfaces need to be newly wired brushed just before assembly. Battery connections need to be re-torqued annually. William Miller At 09:40 AM 3/25/2013, you wrote: Larry, Thanks for your reply. For some reason the schematic I received from the tech at Atkinson did not show any wires being connected to pins 9 10 and as I'm a literalist I did not make those connections. After I received your (and other) feedback I connected gen power to those pins and the AGS seemed to function fine. Within 2 days the customer called me back saying his genny was shutting off after 20 mins of runtime. I told him to disconnect or reprogram one system component at a time to find the fault source. Before a fault source was determined, he observed that two batteries in his bank were experiencing the battery terminals melting into the battery casing (as was texted to me by the customer). I have no idea how a GSCM interface would cause or allow an overcurrent fault at the batteries but the timing of the installation seems to indicate that the AGS is at fault. Ever heard of this before? Eric Stikes SunHarvest Solar We install solar pool pumps quite frequently here in the Caribbean. We use Sunpumps - excellent company, great support. Email Joe Lines j...@sunpumps.com for design assistance, he is very helpful. On Wed, Feb 20, 2013 at 1:02 PM, William Korthof wkort...@gmail.com wrote: A few questions. I have a customer who really wants a solar-direct pool pump for his home. Medium size in-ground pool and I'd like the pump to be strong enough to lift to the solar pool panels (12 ft lift above pool level). I'd like to offer him hardware that is at least one notch above experimental beta-test. I remember the SunCentric from several years ago, but not sure how durable that turned out, and I was having trouble a vendor for it now. Any suggestions for today with some favorable track record? Or suggestions on what to avoid? William Korthof Sustainable Solutions Partners ___ 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 -- 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 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 EM4000SX_MINI-01.PDF___ 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:
[RE-wrenches] AFCI
Wrenches, Are there other string inverters currently in production and available with working AFCI besides SMA? It seems like I would have gotten a hundred emails if there was, but maybe some company with a little smaller profile? Nothing against SMA of course, but their relatively narrow operating voltage window makes design tough in many cases in my climate... Many thanks, -Nathan -- Nathan J. Stumpff NABCEP Certified PV Installer #091209-175 NABCEP Certified Solar Heating Installer #032412-14 Project Manager | Arctic Sun, LLC nat...@arcticsun-llc.com mailto:nat...@arcticsun-llc.com | (907) 457-1297 www.reina-llc.comhttp://www.reina-llc.com | www.arcticsun-llc.comhttp://www.arcticsun-llc.com/ [cid:image001.png@01CE29F8.57138B90]http://www.facebook.com/ArcticSunLLC inline: image001.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
Re: [RE-wrenches] AFCI
Wrenches, Fronius is releasing their AFCI inverters this month. They sent them to me for CEC approval. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Nathan Stumpff Sent: Tuesday, March 26, 2013 9:09 AM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] AFCI Wrenches, Are there other string inverters currently in production and available with working AFCI besides SMA? It seems like I would have gotten a hundred emails if there was, but maybe some company with a little smaller profile? Nothing against SMA of course, but their relatively narrow operating voltage window makes design tough in many cases in my climate. Many thanks, -Nathan -- Nathan J. Stumpff NABCEP Certified PV Installer #091209-175 NABCEP Certified Solar Heating Installer #032412-14 Project Manager | Arctic Sun, LLC nat...@arcticsun-llc.com mailto:nat...@arcticsun-llc.com | (907) 457-1297 www.reina-llc.com | www.arcticsun-llc.com http://www.arcticsun-llc.com/ http://www.facebook.com/ArcticSunLLC Description: ZA102637861 image001.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
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-wrenches] P1 micro performance
Nick, Is Enphase going to be introducing to market any time in the near-term a new micro with a higher output? It seems very likely that the trend toward higher output mods will continue. The M215 will surely be left behind to a greater degree as this trend continues if there are higher and reliable and comparably priced, on a dollar/watt basis, micros available. Thanks, marco Hi Carl, Marco, and Wrenches, As a longtime installer, I understand your point of view. Historically, I designed my string and microinverter systems with the same consideration for maintaining conservative DC to AC ratios. That being said, the costs of modules have decreased significantly and the dynamics have changed. Solar companies should be focused on selling systems that offers a great rate of return. Maximizing the customer's investment is most important. Isn't that what your customer wants? What Enphase is encouraging is the development of cost effective PV systems that will generate a healthy return. Considering that the modules are only 20% of the total system costs today, it is smart to give up 0.2% or more of the module production to lower the overall system costs by 5-10%. The NEC requires that the AC panel boards, conductors, and circuit breakers are sized to the inverter continuous output current rating. We should be maximizing this infrastructure. The data available indicates that when a system is installed with a 1.2 to 1.25 DC to AC ratio, it will rarely operate at peak output. Installing a PV system with a 1.25 DC to AC ratio is not driving the equipment to the maximum. In the case of the Enphase M215s; they are designed to operate continuously at peak output, so reaching that level a few hours in the first years is not problematic. To be clear, this limiting will occur the most during the spring months, because you have a combination of both cool weather and high irradiance levels. As Dan mentioned, this applies to string inverters as well as microinverters. One of the most common system designs of the early US grid-tied market was installing 18- 165 watt modules on an SWR-2500. I designed hundreds of projects like that. That was a ~1.2 multiplier, and was at a time when the modules cost $5 per watt; not $1 per watt. Why be more conservative now? ___ 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
I don't understand how it can be permissible to string the PV wire over the rails, under the modules, and in the rail channels, but not permissible to put it in purpose made cable trays. Makes no sense. ___ 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
In a world where PV wire may be substituted for USE-2, but USE-2 cannot be substituted for PV wire, and (future) 690 wording that only refers to PV wire, there is still question in my mind about proper (future) use in cable trays when 690 over rules 392, as it does in so many other matters. The devil is in the details. From: David Brearley [mailto:david.brear...@solarprofessional.com] Sent: Tuesday, March 26, 2013 12:51 PM To: glenn.b...@glbcc.com; RE-wrenches Subject: 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
Re: [RE-wrenches] P1 micro performance
Friends, Keeping the record straight. I need to say that I have had correspondence 'off list' from a development engineer from a prominent manufacturer who assures me that his product is designed to run 'flat out' 24/7. The unit in fact is just coasting at it's maximum power rating. This allows for a projected life matching that of the PV. In this case power clipping will not shorten the products life. I am unable to confirm if all manufacturers are taking this approach, buyer beware. Regards Carl Emerson Nick, Is Enphase going to be introducing to market any time in the near-term a new micro with a higher output? It seems very likely that the trend toward higher output mods will continue. The M215 will surely be left behind to a greater degree as this trend continues if there are higher and reliable and comparably priced, on a dollar/watt basis, micros available. Thanks, marco Hi Carl, Marco, and Wrenches, As a longtime installer, I understand your point of view. Historically, I designed my string and microinverter systems with the same consideration for maintaining conservative DC to AC ratios. That being said, the costs of modules have decreased significantly and the dynamics have changed. Solar companies should be focused on selling systems that offers a great rate of return. Maximizing the customer's investment is most important. Isn't that what your customer wants? What Enphase is encouraging is the development of cost effective PV systems that will generate a healthy return. Considering that the modules are only 20% of the total system costs today, it is smart to give up 0.2% or more of the module production to lower the overall system costs by 5-10%. The NEC requires that the AC panel boards, conductors, and circuit breakers are sized to the inverter continuous output current rating. We should be maximizing this infrastructure. The data available indicates that when a system is installed with a 1.2 to 1.25 DC to AC ratio, it will rarely operate at peak output. Installing a PV system with a 1.25 DC to AC ratio is not driving the equipment to the maximum. In the case of the Enphase M215s; they are designed to operate continuously at peak output, so reaching that level a few hours in the first years is not problematic. To be clear, this limiting will occur the most during the spring months, because you have a combination of both cool weather and high irradiance levels. As Dan mentioned, this applies to string inverters as well as microinverters. One of the most common system designs of the early US grid-tied market was installing 18- 165 watt modules on an SWR-2500. I designed hundreds of projects like that. That was a ~1.2 multiplier, and was at a time when the modules cost $5 per watt; not $1 per watt. Why be more conservative now? ___ 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] Sparq Micro-Inverters
Hey Wrenches, Do any of you have any experience with Sparq micro-inverters? SPARQ Systems Inc. http://www.sparqsys.com/ Any feedback? I have installed one system so far using them, but the (new construction) home will not have internet access for several months, so remote monitoring is not possible yet. I know of at least one other in the area. They are very much like the M190 in appearance and interconnection method (daisy-chain) but I'm told that the next generation will likely be much smaller in size. The technology they are using is resonant conversion (I hope I got that right), which as I understand makes the units themselves more software rather than hardware This also eliminates some of the failure prone components of a typical inverter, so they are confidant coming out of the gate with a 25yr warranty. Pretty bold for a newer company/product, but they are pretty confidant with their technology and everyone has to start somewhere Benn DayStar Renewable Energy Inc. www.daystarsolar.ca 780-906-7807 Construction Electrician Solar PV Systems Certified Certificate # 0007S HAVE A SUNNY DAY ___ 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
Bill: I have to disagree with you on this one. We can not abandoned a tried and true practice just because some practitioners don't do it right. I don't know how one can justify saying that encapsulating high voltage conductors in a conduit is less safe than exposed in a flimsy basket. Consider snow and ice and falling objects. Too many installers entered the PV field without first acquiring the necessary skills as journeymen or women electricians. I don't see the benefit of rewriting the code to accommodate a lack of skills in the industry. Respectfully, William Miller PS: The temperature adders always encourage us to enter the building envelope at the first appropriate location to avoid adding them. Thoughtful installers will do the same. Wm At 10:15 PM 3/25/2013, you wrote: Content-Type: multipart/alternative; boundary==_NextPart_000_00E3_01CE29A6.37CC5110 Content-Language: en-us William, I would strongly disagree that conduit is tried and true on rooftops. I have rarely seen good conduit runs on rooftops. Most electricians have no clue how to work with expansion joints. Conduit on rooftops is a bad idea in general. Most conduit runs in big buildings are all done indoors for good reason. We are the crazy people doing things on the roof. The sooner we get away from conduitparticularly for long feeder runsthe better. In Europe they dont have problems with their rooftop wiring systems because everything is in tray. For those that dont allow cable tray for anything less than 1/0, just remember that if it isnt called cable tray, then 392 doesnt apply. The NEC would allow us to use treated lumber in place of cable tray. This makes no sense. We did some research on the origin of the 1/0 requirement, and it is ancient and no longer relevant. Just because it is in the code, does not mean it is correct. Thats why we try to fix it every three years. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Monday, March 25, 2013 9:30 PM To: RE-wrenches Subject: Re: [RE-wrenches] Cable tray David: Of course, I understand that you are not saying we can willfully disregard the Code in anticipation of future clarification. I was just extrapolating on your idea. If we want an exception based on a predicted update in the code, we are at the mercy of the AHJ who may or may not be convinced. I think most AHJs are willing to diverge from the Code in a more strict interpretation, but not the reverse. Right now, as I read it, unless the leads are 1/0 or larger, we are forbade. I treat PV systems like rooftop AC units. The voltages and currents are similar, if not more severe. I don't believe you could or should run power to a rooftop AC unit in cable tray. Conduit is a tried and true practice and I recommend it. William Miller At 06:01 PM 3/25/2013, you wrote: 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
Re: [RE-wrenches] Cable tray
William, I have all the respect in the world for you, but I'm not referring to basket tray, which is only appropriate for small conductors. I'm talking about legitimate cable tray that can be up to 12 wide and that has a top and rungs every 12. The main facilities that use it in the United States are large industrial facilities. Most electricians don't get to work with it. It is clearly superior to EMT and is at least as good as IMC without all the hassle of threaded fittings and setting up expansion joints and worrying about 20 years of conductors thermal cycling. Even the best electricians have problems with this stuff. I am talking about projects with 800 foot long feeder runs. We can bring them in the building and build a rack for the conduit or run covered tray outside. As the 2014 NEC will require, you will have to use contactor combiners or some other means to shut down the conductors inside a building. It's all doable. My recommendation after seeing the aftermath of rooftop conduit by good electricians is to put cable tray on roofs and use conduit if you bring the feeders indoors. It will become common practice soon. Hopefully sooner than later. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Tuesday, March 26, 2013 9:49 PM To: RE-wrenches Subject: Re: [RE-wrenches] Cable tray Bill: I have to disagree with you on this one. We can not abandoned a tried and true practice just because some practitioners don't do it right. I don't know how one can justify saying that encapsulating high voltage conductors in a conduit is less safe than exposed in a flimsy basket. Consider snow and ice and falling objects. Too many installers entered the PV field without first acquiring the necessary skills as journeymen or women electricians. I don't see the benefit of rewriting the code to accommodate a lack of skills in the industry. Respectfully, William Miller PS: The temperature adders always encourage us to enter the building envelope at the first appropriate location to avoid adding them. Thoughtful installers will do the same. Wm At 10:15 PM 3/25/2013, you wrote: Content-Type: multipart/alternative; boundary==_NextPart_000_00E3_01CE29A6.37CC5110 Content-Language: en-us William, I would strongly disagree that conduit is tried and true on rooftops. I have rarely seen good conduit runs on rooftops. Most electricians have no clue how to work with expansion joints. Conduit on rooftops is a bad idea in general. Most conduit runs in big buildings are all done indoors for good reason. We are the crazy people doing things on the roof. The sooner we get away from conduit-particularly for long feeder runs-the better. In Europe they don't have problems with their rooftop wiring systems because everything is in tray. For those that don't allow cable tray for anything less than 1/0, just remember that if it isn't called cable tray, then 392 doesn't apply. The NEC would allow us to use treated lumber in place of cable tray. This makes no sense. We did some research on the origin of the 1/0 requirement, and it is ancient and no longer relevant. Just because it is in the code, does not mean it is correct. That's why we try to fix it every three years. Bill. ___ 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
