Re: [RE-wrenches] Enphase voltage out of range errors
This has been a common error on M190's for us. Is the string center fed, or fed from one end of the 17 inverter string? Where are the failed inverters on the string in relation to the transition cable(s)? Enphase has an App Note on voltage rise that might be relevant. They recommend center feeding long strings to avoid nuisance trips due to voltage range issues. *Jason Szumlanski** * *Fafco Solar* On Mon, Nov 26, 2012 at 3:46 PM, William Miller will...@millersolar.comwrote: Friends: We have one site that is experiencing ongoing problems with errors indicating, AC Voltage Out Of Range. This has occurred on two of 17 M190 inverters. Apparently the voltage is not really out of range, the inverter is erroneously reporting. I have one replacement in hand and was just about to drive the 2 hours to replace it when another inverter indicated the same problem. I ordered a second replacement. I fear that soon after I return to my shop from the job I will see another inverter with this problem. Has anyone else experienced this error? Thanks in advance, William 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-wrenc...@lists.re-wrenches.**orgRE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/**options.cgi/re-wrenches-re-**wrenches.orghttp://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/**pipermail/re-wrenches-re-** wrenches.orghttp://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.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] PVSYST or similar analysis needed
Carl, you may also be interested in HOMER-- free 2-week trial available of the latest version (after that, $99 per 6-month renewal, despite zero updates since Nov 2010). There's also the free legacy version that's a few years old. http://homerenergy.com/ On 2012/11/26 22:40, Carl Adams wrote: Hello Wrenches, I am in need of an analysis for a large battery backup system. I am looking for a sweet spot in PV array size and battery bank size. I need this modeled on a time of day basis, and evaluated monthly thru a full calendar year. I am told that PVSYST can perform such an analysis but I neither have the tool nor the experience using it to perform the modeling, so I am looking to hire the job out to someone who does. If any of you have the software and expertise to use it please contact me off list for more detailed requirements. With Regards 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] Best practices for conduit penetration on roof
We're pretty fortunate that a roof mounted readily accessible disconnect has not been a sticking point locally. I would argue that the AC disconnect is still the trunk cable connector, which can be not readily accessible. The AC breaker carrying the combined circuit output in the main distribution panel or the fusible disconnect switch if performing a supply side connection would qualify as the readily accessible disconnect. If you install Enphase I'm sure you are familiar with the manufacturer's excellent white paper on this issue. I hear what you are saying about the temperature concerns, but there are many installations that have far fewer than 17 inverters per string. A typical residential installation can be split into two or three branch circuits (thank you, Andrew, for keeping me accurate on the string/circuit thing!) The temp concern is definitely something to explore further. There is also the thermal interference factor to take into account for multiple breakers that Gary did not mention. The full datasheet is here: http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/11d7d0032b466358c125712400340107/$file/2CDC002052D0203_UL489.pdf As for the interior rated breaker comment, typical AC branch circuit breakers (i.e. Sq D QO) are mounted in wet location NEMA 3R boxes all the time on the exterior of a building. I'm not sure I understand this concern. The temperature derating curve is also similar for ABB and QO breakers. QO Datasheet here: http://static.schneider-electric.us/docs/Circuit%20Protection/Miniature%20Circuit%20Breakers/QO-QOB%20Circuit%20Breakers/0730CT9801R108.pdf I definitely want to be 100% sure the SolaDeck and breakers are appropriately rated before proceeding. Any comments welcomed... *Jason Szumlanski** * *Fafco Solar* On Mon, Nov 26, 2012 at 6:37 PM, Gary Willett g...@icarussolarservices.comwrote: JASON: I talked to Steve Capozzi of SolaDeck and he sent me additional info about the circuit breakers: *Manufacturer*: ABB *Terminal Temp Rating*: 75C / 167F *Reference Temperature*: 20C / 68F *Ambient Temp Derating*: 30C/86F = 18.7A 40C/104F = 17.3A 50C/122F = 15.8A 60C/140F = 14.1A 70C/158F = 12.2A My concern is that we may be attempting to use an interior rated AC breaker in a roof-deck-mounted NEMA3-R enclosure. In an Enphase application, with the maximum of 17 inverters per AC Source Circuit, the continuous current will be 0.9A x 17 x 1.25 = 19.1A. This exceeds the 30C/86F trip current of 18.7A. The interior temperature of the SolaDeck could very likely approach the 60C/140F trip current of 14.1A. It seems to me that nuisance trips could be a high probability event. Does anyone have any field experience using this Soladeck option for a AC Source Circuit Combiner Box (SCCB)? Another issue, at least in some jurisdictions, is the requirement for a roof-top AC Disconnect. The SolaDeck, when used as an AC SCCB, may not meet the NEC Article 100 requirements in some jurisdictions for readily accessible because a tool is required to open it. Regards, Gary Willett, PE Icarus Engineering LLC Icarus Solar Services LLC On 11/26/2012 2:21 PM, Jason Szumlanski wrote: I did get some pictures and info from Soladeck. Here are some links: Pics: https://docs.google.com/open?id=1BpiL-1SdSNNsj4wPMQrFCLHH7JT2dek_KftSJl06QLqc0yhJ_1t5oij0aEA6 https://docs.google.com/open?id=1cVuhZGeQNHL1IvGvNBa7v93oZyGBvjxCv5yq4AmoyJeDAITxvgMqgECR2yTv https://docs.google.com/open?id=1umslTplnFyZG1eNCZE-MMi_OqrSeirFCPRBl9mFNZJ2gQkBjM5LEXnaPKy2l Specs: https://docs.google.com/open?id=13KLAuxUHOR9al7-36reDSJJ7IMnqV3ANPnJILPnrj2xcAi0ksRj67ifKIe7R https://docs.google.com/open?id=1kvPFcDc1vruS3W_aONlXyIHm1T8-qi4vTpTwGGJ7H0eIwuZ-5e6zrM1CcND5 https://docs.google.com/open?id=1lM8FtYl9HiYohru32UA_Gb1tXZKZ5iw-8tnSu1Un6g4vcklLL-DK1qLPMdsB I was told Soligent can source the combiners for you (and me). *Jason Szumlanski** * *Fafco Solar* http://www.wisestamp.com/apps/wordpress?utm_source=extensionutm_medium=emailutm_term=wordpressutm_campaign=apps On Mon, Nov 26, 2012 at 1:50 PM, Jason Szumlanski ja...@fafcosolar.comwrote: I just called Soladeck and they are sending me some more info on availability. I'll pass it along when I get it. I didn't realize they made an AC roof mounted string combiner solution. That's a huge help for 2 or 3 string Enphase installations (they make both combiners). While on the subject, we recently started using the Enphase cable couple with Type TC-ER cable to extend cabling to junction boxes when necessary... No more wasting trunk cable connectors! I suppose Type TC-ER could be used all the way to the main distribution panel, thereby eliminating junctions on the roof, but I haven't looked into the cost/benefit of that idea. *Jason Szumlanski* *Fafco Solar* ___ List sponsored by Home Power magazine List Address:
Re: [RE-wrenches] Unisolar Intermittent Ground Fault
Hi Robert, Get a mega Ohm meter, isolate the home runs and perform a test. You should get 550 MOhms. If not, there's something likely wrong with that string that's causing the intermittent ground fault. Or, have someone stand on the ground with a hose pointing it at the roof and try to find it using the voltage method you've been doing. Date: Mon, 26 Nov 2012 16:55:16 -0800 From: Robert Nuese robertnu...@sonic.net To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Unisolar Intermittent Ground Fault Message-ID: 9c067b77-378b-40ed-ab44-ff966dc20...@sonic.net Content-Type: text/plain; charset=us-ascii 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. nt. Any recommendations? Probably needs to be someone within 100 miles of Sebastopol CA. Thanks, Robert Nuese ___ 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] Unisolar Intermittent Ground Fault
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 before I go into more detail. SO what am I missing? What test should I do? How can I fix this problem? OR does anyone know of somebody with more expertise who I could hire to help? I'm a fairly experienced solar installer, but I think this might be something that requires an electrical (or electronic?) engineer with a deep understanding of electrical theory, and with some advanced test equipment. Any recommendations? Probably needs to be someone within 100 miles
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] Enphase voltage out of range errors
William Double check your voltage drop on the AC branch circuits, and make sure that you consider your wiring between inverters. Remember that voltage drop is additive and each inverter will see a slightly lower voltage drop which could account for the voltage over error, especially if you are seeing it at the end of the string. Enphase does have a white paper on that and they are now recommending splitting long strings int he middle to make to branch circuits out of one now to alleviate this problem. The White Paper explains this in more detail. There was also a Solar Pro article describing how voltage drop can result in voltage rise at the inverter, and I have seen and measured this with a meter. Maybe the inverters are correctly reporting the voltage rise? Bill On Mon, Nov 26, 2012 at 12:46 PM, William Miller will...@millersolar.comwrote: Friends: We have one site that is experiencing ongoing problems with errors indicating, AC Voltage Out Of Range. This has occurred on two of 17 M190 inverters. Apparently the voltage is not really out of range, the inverter is erroneously reporting. I have one replacement in hand and was just about to drive the 2 hours to replace it when another inverter indicated the same problem. I ordered a second replacement. I fear that soon after I return to my shop from the job I will see another inverter with this problem. Has anyone else experienced this error? Thanks in advance, William 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-wrenc...@lists.re-wrenches.**orgRE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/**options.cgi/re-wrenches-re-**wrenches.orghttp://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/**pipermail/re-wrenches-re-** wrenches.orghttp://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.org -- Bill Hoffer PE NABCEP Certified Solar PV Installer™ Sunergy Engineering Services PLLC 2504 Columbia Ave NW East Wenatchee WA 98802-3941 bhof...@sunergyengineeringservices.com Cell:(509)679-6165 ___ 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-wrenches] 3 Phase With 2 Inverters?
We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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] Enphase voltage out of range errors
Bill: Good question. I called Enphase back and they say it is definitely a hardware problem. There are at least two registers that indicate AC line voltage and in this case they disagree, with VRMS indicating zero. Enphase has advanced diagnostics they can call up on-line, apparently. William At 09:49 AM 11/27/2012, you wrote: William Double check your voltage drop on the AC branch circuits, and make sure that you consider your wiring between inverters. Remember that voltage drop is additive and each inverter will see a slightly lower voltage drop which could account for the voltage over error, especially if you are seeing it at the end of the string. Enphase does have a white paper on that and they are now recommending splitting long strings int he middle to make to branch circuits out of one now to alleviate this problem. The White Paper explains this in more detail. There was also a Solar Pro article describing how voltage drop can result in voltage rise at the inverter, and I have seen and measured this with a meter. Maybe the inverters are correctly reporting the voltage rise? Bill ___ 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] 3 Phase With 2 Inverters?
Hi Holt, We installed a commercial system a year ago for the National Park Service that was designed by a competitor (?) and signed off on by an engineer. It consisted of 13.2 kw of pv and two Fronius 7000 watt, 208 3 ph. inverters. It sounds a lot like what you are dealing with. I questioned the engineer on it and he said because the facility was so large (it was a large research and visitor campus for Acadia National Park with 20+ buildings)the transformer would never see the imbalance and therefore was not a problem. Fronius agreed, but prefaced that with the fact that it still was not recommended. I can say that we have had no issues or complaints at all since the installation in August of 2011 and they monitor it continuously. It would have been a far better design to use three Fronius 4.5 inverters at 3 ph. I drafted a letter (CYA letter) to the powers that be about my concerns (transformer imbalance) and they chose to go ahead with the installation. Nothing like government work...many more stories about this installation than anyone has time for here. Daryl DeJoy NABCEP Certified PV installer Penobscot Solar Design We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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-wrenches] Very small, auto-start gas generator?
Hello esteemed Wrenches; Has anyone here ever come across a very small, quiet gasoline or propane generator (no more than 2kw) that can be auto-started? Or electronics that could do that for a stock generator? A Honda 1000i or 2000i would be ample, but is not auto start. This is for 12VDC perimeter security cameras / GSM routers at extremely remote sites, and PV design autonomy time may not be ample if the weather is terrible, roads are washed out etc. Thanks in advance! -- Dan Fink, Executive Director; Otherpower Buckville Energy Consulting Buckville Publications LLC NABCEP / IREC accredited Continuing Education Providers 970.672.4342 (voicemail) ___ 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] 3 Phase With 2 Inverters?
Hi holt, Just FYI, Fronius will pay you $250 each to swap the inverters. Larry Crutcher Starlight Solar Power Systems On Nov 27, 2012, at 12:59 PM, hol...@sbcglobal.net hol...@sbcglobal.net wrote: We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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] 3 Phase With 2 Inverters?
I would agree that the imbalance at these power levels is not a major issue. If it appears that Phase A is most heavily-loaded, I'd install the inverters as A-B and A-C to help mitigate the existing imbalance. If you've got a lot of 1P loads on a 3P service-- lighting, office receptacles or whatever-- you could easily have a large imbalance on a regular basis. The 7kVA PV imbalance in your installation would happen extremely rarely. If this imbalance still makes you uneasy, then install three inverters and then a relay system to bring all the inverters down in case any of them fails. The SMA Power Balancer does this for their inverters and maybe some third-parties offer them too for these Fronius installs. This seems to make the most sense for decentralized systems with many string inverters, to ensure that a low phase voltage doesn't turn off a fraction of your inverters and cause a 100kVA imbalance. I've heard that some utilities have a max PV imbalance (calculated from the inverter ratings) of 6kVA. No utility to my knowledge requires an interconnection agreement for a 10kVA single-phase commercial water heater (to steal a Bill Brooks example) that would have a much stronger impact. Dave On 2012/11/27 15:14, penobscotso...@midmaine.com wrote: Hi Holt, We installed a commercial system a year ago for the National Park Service that was designed by a competitor (?) and signed off on by an engineer. It consisted of 13.2 kw of pv and two Fronius 7000 watt, 208 3 ph. inverters. It sounds a lot like what you are dealing with. I questioned the engineer on it and he said because the facility was so large (it was a large research and visitor campus for Acadia National Park with 20+ buildings)the transformer would never see the imbalance and therefore was not a problem. Fronius agreed, but prefaced that with the fact that it still was not recommended. I can say that we have had no issues or complaints at all since the installation in August of 2011 and they monitor it continuously. It would have been a far better design to use three Fronius 4.5 inverters at 3 ph. I drafted a letter (CYA letter) to the powers that be about my concerns (transformer imbalance) and they chose to go ahead with the installation. Nothing like government work...many more stories about this installation than anyone has time for here. Daryl DeJoy NABCEP Certified PV installer Penobscot Solar Design We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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] 3 Phase With 2 Inverters?
I really don't understand what your problem with this arrangement is. How would this be different from a house on phase A-B installing an inverter and the next house on Phase B-C installing an inverter? Or, installing two single phase 240V A/C units in a three phase building? Electricians have no issue with installing single phase equipment in three phase buildings so why should small inverters be any more a problem. While it is always neat to install three inverters n a three phase configuration, 4,500 watts of imbalance is trivial. On Tue, Nov 27, 2012 at 3:59 PM, hol...@sbcglobal.net wrote: ** We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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 -- 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
Re: [RE-wrenches] Very small, auto-start gas generator?
The problem you will face with such a small generator is the run time rating. You are likely to put a large number of hours on this and you will kill a little 2KW gas generator quickly. The service interval will be too short for this type of use. Additionally, they are generally not designed to be outdoor use and cannot be used indoor. How will you house it? How will you connect more than a few hours fuel? You can get a 6KW Generac ecogen that is rated for 500 hours between service and designed for this kind of run time. Comes with weather proof housing and can be run from a large fuel tank. On Tue, Nov 27, 2012 at 4:53 PM, Dan Fink danbo...@gmail.com wrote: Hello esteemed Wrenches; Has anyone here ever come across a very small, quiet gasoline or propane generator (no more than 2kw) that can be auto-started? Or electronics that could do that for a stock generator? A Honda 1000i or 2000i would be ample, but is not auto start. This is for 12VDC perimeter security cameras / GSM routers at extremely remote sites, and PV design autonomy time may not be ample if the weather is terrible, roads are washed out etc. Thanks in advance! -- Dan Fink, Executive Director; Otherpower Buckville Energy Consulting Buckville Publications LLC NABCEP / IREC accredited Continuing Education Providers 970.672.4342 (voicemail) ___ 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
Re: [RE-wrenches] Very small, auto-start gas generator?
We are looking at a load of about 100 watts, 24/7, and the locations would be in the Caribbean with 5-6 full sun hours daily, most days. I don't foresee a large amount of generator run time, but storms and fog happen. This is not in the USA, so I also see issues in obtaining AGM batteries. Golf car batteries are common. I'm not seeing much out there for tiny generators, and I'm starting to think that the occasional hammering of a golf car battery bank by a week-long period of no sun might be more cost-effective -- it won't happen very often, and I believe the 12vdc gear they are running is really 5vdc USB, so their power supply won't cut out until 10,5 vdc. I believe that lack of noise is also an issue. The one thing they don't lack down there is sun, that's for sure. A hammered battery bank would fill in a day. Hmmm..contemplating this. Thanks for your input, all! DAN FINK On Tue, Nov 27, 2012 at 3:41 PM, Chris Mason cometenergysyst...@gmail.comwrote: The problem you will face with such a small generator is the run time rating. You are likely to put a large number of hours on this and you will kill a little 2KW gas generator quickly. The service interval will be too short for this type of use. Additionally, they are generally not designed to be outdoor use and cannot be used indoor. How will you house it? How will you connect more than a few hours fuel? You can get a 6KW Generac ecogen that is rated for 500 hours between service and designed for this kind of run time. Comes with weather proof housing and can be run from a large fuel tank. ___ 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] Very small, auto-start gas generator?
AGM are easy to ship in, in fact they are easier than flooded due to Hazmat shipping issues. What island? On Tue, Nov 27, 2012 at 7:01 PM, Dan Fink danbo...@gmail.com wrote: We are looking at a load of about 100 watts, 24/7, and the locations would be in the Caribbean with 5-6 full sun hours daily, most days. I don't foresee a large amount of generator run time, but storms and fog happen. This is not in the USA, so I also see issues in obtaining AGM batteries. Golf car batteries are common. I'm not seeing much out there for tiny generators, and I'm starting to think that the occasional hammering of a golf car battery bank by a week-long period of no sun might be more cost-effective -- it won't happen very often, and I believe the 12vdc gear they are running is really 5vdc USB, so their power supply won't cut out until 10,5 vdc. I believe that lack of noise is also an issue. The one thing they don't lack down there is sun, that's for sure. A hammered battery bank would fill in a day. Hmmm..contemplating this. Thanks for your input, all! DAN FINK On Tue, Nov 27, 2012 at 3:41 PM, Chris Mason cometenergysyst...@gmail.com wrote: The problem you will face with such a small generator is the run time rating. You are likely to put a large number of hours on this and you will kill a little 2KW gas generator quickly. The service interval will be too short for this type of use. Additionally, they are generally not designed to be outdoor use and cannot be used indoor. How will you house it? How will you connect more than a few hours fuel? You can get a 6KW Generac ecogen that is rated for 500 hours between service and designed for this kind of run time. Comes with weather proof housing and can be run from a large fuel tank. ___ 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
[RE-wrenches] Info On 2 V batteries Please
We recently purchased a battery powered forklift, with 24 ea. 2V batteries. Approximate dimensions: W=5, L=6-3/16, H=~21 (hard to tell). Enersys is stamped on the top. The battery supplier claims the batteries are 24-85-13 but this refers to a 24V battery as far as I can tell. He also claims that the batteries are rated at 510-550 A-hr. I am assuming that the lower number is for 6 hours discharge. I would like to know more about the batteries. Also, how to discharge / charge them. Should they be run down to 20% SOC and then fully charged? What if we don't use the forklift for a week at a time? Based on my experience of using AGM batteries, it would seem that the Bulk charging rate should be some percentage (e.g. 20%) of the 6-hour ampacity, then there is a constant voltage absorption charge (e.g. Vabs=2.385 V), and a switch to Float when the charging current drops to some low percentage (e.g. 0.5% of capacity), and the Float voltage being 2.125 V. Again everything at 25 deg C. It seems like the forklift guys like to refer everything to a 6 hour capacity, which may be related to the maximum typical daily usage. What is the relationship between Voc and SOC after resting the battery for 6 hours at 25 deg C? Thanks in advance for your help, guys. - Peter Parrish Alternative Energy Department College of the Canyons peter.parr...@canyons.edu O: (661) 362-3888 C: (323) 839-6108 ___ 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] 3 Phase With 2 Inverters?
Bill Brooks posted this in 2008. A couple of project-specific sentences were removed to avoid confusion. The 6kVA value comes from the California Rule 21 that I worked on. It only applies to split-phase 240V systems (6kVA on 120V). There is no specific limit for imbalance on a 3-phase service. A basic rule for single phase generation on a 3=phase service is to rotate among the phases in a balanced manner... ...The best way to place the imbalanced single-phase generators on the service is to test the current on all three phases and put the inverter(s) on the most heavily loaded phase(s). This reduces the site imbalance by reducing the imbalance on the serving transformer (lowering current on the most heavily loaded phases). It is common for 3-phase services to have imbalances of 10 kVA or more, so single-phase inverters can reduce the problem rather than make it worse. For a brighter energy future, Andrew Truitt NABCEP Certified PV Installer™ (ID# 032407-66) Principal Truitt Renewable Energy Consulting (202) 486-7507 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 Tue, Nov 27, 2012 at 3:33 PM, Chris Mason cometenergysyst...@gmail.comwrote: I really don't understand what your problem with this arrangement is. How would this be different from a house on phase A-B installing an inverter and the next house on Phase B-C installing an inverter? Or, installing two single phase 240V A/C units in a three phase building? Electricians have no issue with installing single phase equipment in three phase buildings so why should small inverters be any more a problem. While it is always neat to install three inverters n a three phase configuration, 4,500 watts of imbalance is trivial. On Tue, Nov 27, 2012 at 3:59 PM, hol...@sbcglobal.net wrote: ** We were asked to inspect a GT system installed by others. Service is 208 3ph with two (?) Fronius IG 4500 208v inverters. The inverter panel is 3ph with two 2pole breakers - one each side of the buss bar in a A/B, B/C configuration (??). Called Fronius and they said it would work, but they don't recommend it. No other information was given as to why they don't. My electrician is very uncomfortable with doing work on this system as is (ME TOO!), so I am wondering if I might be able get some ammo to convince system owner to add a third inverter to get the system right. What problems might/will be encountered in this system if not modified? BTW - inverter LCD screens were crapped out, so we couldn't readily see if system was functioning properlyfrom metering, we think not. Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.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 -- 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 ___ 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-wrenches] Unisolar Intermittent Ground Fault
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
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] Info On 2 V batteries Please
Peter: These batteries sound like IBE 85N batteries. See link below. I need to warn you that this company has about the worse web site in the industry. http://www.ibe-inc.com/html/altenergy.htm William At 01:31 PM 11/27/2012, you wrote: We recently purchased a battery powered forklift, with 24 ea. 2V batteries. Approximate dimensions: W=5, L=6-3/16, H=~21 (hard to tell). Enersys is stamped on the top. The battery supplier claims the batteries are 24-85-13 but this refers to a 24V battery as far as I can tell. He also claims that the batteries are rated at 510-550 A-hr. I am assuming that the lower number is for 6 hours discharge. ___ 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] Info On 2 V batteries Please
These batteries can take a 2000 or so cycles to 20% dod before they are worn out. Both numbers could be the 6 hour rate, it varies with electrolyte strength. Somewhere between 1.265 and 1.285 SG, some hi acid cells are 1.325 SG. The 24 means 24 cells, the 85 is the 85 AH plates and the 13 means 13 positive plates. Those will weigh 90 - 100# for each cell. Can send you more info if you want. Got to run, Bob Ellison -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Parrish, Peter Sent: Tuesday, November 27, 2012 4:31 PM To: RE-wrenches Subject: [RE-wrenches] Info On 2 V batteries Please We recently purchased a battery powered forklift, with 24 ea. 2V batteries. Approximate dimensions: W=5, L=6-3/16, H=~21 (hard to tell). Enersys is stamped on the top. The battery supplier claims the batteries are 24-85-13 but this refers to a 24V battery as far as I can tell. He also claims that the batteries are rated at 510-550 A-hr. I am assuming that the lower number is for 6 hours discharge. I would like to know more about the batteries. Also, how to discharge / charge them. Should they be run down to 20% SOC and then fully charged? What if we don't use the forklift for a week at a time? Based on my experience of using AGM batteries, it would seem that the Bulk charging rate should be some percentage (e.g. 20%) of the 6-hour ampacity, then there is a constant voltage absorption charge (e.g. Vabs=2.385 V), and a switch to Float when the charging current drops to some low percentage (e.g. 0.5% of capacity), and the Float voltage being 2.125 V. Again everything at 25 deg C. It seems like the forklift guys like to refer everything to a 6 hour capacity, which may be related to the maximum typical daily usage. What is the relationship between Voc and SOC after resting the battery for 6 hours at 25 deg C? Thanks in advance for your help, guys. - Peter Parrish Alternative Energy Department College of the Canyons peter.parr...@canyons.edu O: (661) 362-3888 C: (323) 839-6108 ___ 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] Info On 2 V batteries Please
Hi Peter Are these 12 batteries in a large single steel case? And are they flooded or VRLA? Thx Jay Peltz power Sent from my iPhone On Nov 27, 2012, at 1:31 PM, Parrish, Peter peter.parr...@canyons.edu wrote: We recently purchased a battery powered forklift, with 24 ea. 2V batteries. Approximate dimensions: W=5, L=6-3/16, H=~21 (hard to tell). Enersys is stamped on the top. The battery supplier claims the batteries are 24-85-13 but this refers to a 24V battery as far as I can tell. He also claims that the batteries are rated at 510-550 A-hr. I am assuming that the lower number is for 6 hours discharge. I would like to know more about the batteries. Also, how to discharge / charge them. Should they be run down to 20% SOC and then fully charged? What if we don't use the forklift for a week at a time? Based on my experience of using AGM batteries, it would seem that the Bulk charging rate should be some percentage (e.g. 20%) of the 6-hour ampacity, then there is a constant voltage absorption charge (e.g. Vabs=2.385 V), and a switch to Float when the charging current drops to some low percentage (e.g. 0.5% of capacity), and the Float voltage being 2.125 V. Again everything at 25 deg C. It seems like the forklift guys like to refer everything to a 6 hour capacity, which may be related to the maximum typical daily usage. What is the relationship between Voc and SOC after resting the battery for 6 hours at 25 deg C? Thanks in advance for your help, guys. - Peter Parrish Alternative Energy Department College of the Canyons peter.parr...@canyons.edu O: (661) 362-3888 C: (323) 839-6108 ___ 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] Unisolar Intermittent Ground Fault
http://www.amazon.com/Extech-380260-Autoranging-Digital-Insulation/dp/B000EWW2UA/ref=sr_1_1?ie=UTF8qid=1354065758sr=8-1keywords=extech+insulation $239 On Tue, Nov 27, 2012 at 7:32 PM, Robert Nuese robertnu...@sonic.net 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 -- 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:
