[RE-wrenches] Extensive Lightning Damage to Modules
A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I've seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We're trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 - 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we've tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.commailto:j...@hudsonsolar.com Solar Electric Systems NYSERDA Eligible PV Installer NABCEP Certified Solar PV Installer NABCEP Certified PV Technical Sales HudsonSolar.comapplewebdata://B5F2562A-2B67-4161-84E4-42F12DC28720/www.hudsonsolar.com 2011 NYSERDA Excellence in Quality Award | 2011 NYSEIA Award Winner | 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year | EDC Business Excellence Award for Innovation ___ 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] Extensive Lightning Damage to Modules
Hello Jeff, I am curious about the network of ground rods and #6 wire. Can you describe how the modules and mount are connected to this ground system? Are there any tight bends anywhere in the #6 wire? Are any of the poles or mounts connected to other poles/mounts before going to the ground system? Are any PV wires running between the poles before going to the combiner? As most wrenches know, lightning strikes can induce very high voltage on any nearby wire runs and that voltage is looking for a path to ground. Equipment is damaged when it contributes to that path. If the voltage was induced on the PV module frames or wire, an effective ground system will disperse it to ground. Key word here is effective. I have seen grounding systems where the installer made nice, neat and tight 90° bends in the ground wire. This is a huge mistake which can greatly diminish the effectiveness of the ground system. Larry Crutcher Starlight Solar Power Systems On Sep 7, 2012, at 8:40 AM, Jeff Irish wrote: A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I’ve seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We’re trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 – 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we’ve tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.com Solar Electric Systems NYSERDA Eligible PV Installer NABCEP Certified Solar PV Installer NABCEP Certified PV Technical Sales HudsonSolar.com 2011 NYSERDA Excellence in Quality Award | 2011 NYSEIA Award Winner | 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year | EDC Business Excellence Award for Innovation ___ 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] Extensive Lightning Damage to Modules
Jeff, Is there any surge protection in the combiner boxes? Any damage visible in the combiner boxes? Any fuses or breakers open in the combiner boxes? Is each pole a single string of modules or multiple strings of modules? While there where undoubtedly ground currents flowing they probably didn't cause the damage in the module junction boxes. The PV module and wiring to it form a loop - often a loop with a large area in the vicinity of the module. The current from the lightning strike has a tremendous dI/dt and the changing magnetic field from it will induce voltages in any wire loop. Kent Osterberg Blue Mountain Solar, Inc. www.bluemountainsolar.com t: 541-568-4882 On 9/7/2012 7:40 AM, Jeff Irish wrote: A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I've seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We're trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 -- 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we've tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.com mailto:j...@hudsonsolar.com /Solar Electric Systems/ /NYSERDA Eligible PV Installer/ /NABCEP Certified Solar PV Installer/ /NABCEP Certified PV Technical Sales/ HudsonSolar.com applewebdata://B5F2562A-2B67-4161-84E4-42F12DC28720/www.hudsonsolar.com 2011 NYSERDA Excellence in Quality Award | 2011 NYSEIA Award Winner | 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year | EDC Business Excellence Award for Innovation ___ 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] Extensive Lightning Damage to Modules
I've seen it twice. both were DPW pole Mounts. the first time the whole array was involved (this was a few years ago). At the time, we thought it might be a disgruntled employee because no one had ever heard of such damage. I think we used box lugs and star washers on each module back then). the second just a few weeks ago. this time it seemed totally random affecting about 30% in different strings. Seems back in the broadcast industry we viewed lightening strikes as "Acts of God", and focused more on repair than the "whys". We install as per manufacturer's spec and NEC, and cross our fingers.. But when the Good Lord comes knocking, all bets are off. I remember pulling onto a job site once and found 80 lb chunks of chimney/ fireplace some 150ft down the driveway. Yes, the house did have lightening rods. Good Luck. dbDan BrownFoxfire Energy Corp.Renewable Energy Systems(802)-483-2564www.Foxfire-Energy.comNABCEP #092907-44 Original Message ---- Subject: [RE-wrenches] Extensive Lightning Damage to Modules From: Jeff Irish j...@hudsonsolar.com Date: Fri, September 07, 2012 10:40 am To: "RE-wrenches@lists.re-wrenches.org" RE-wrenches@lists.re-wrenches.org A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I’ve seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We’re trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 – 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open.The odd thing is the pattern of damage (we’ve tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.com Solar Electric Systems NYSERDA Eligible PV Installer NABCEP Certified Solar PV Installer NABCEP Certified PV Technical Sales HudsonSolar.com 2011 NYSERDA Excellence in Quality Award|2011 NYSEIA Award Winner| 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year|EDCBusiness Excellence Award for Innovation ___ 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] Extensive Lightning Damage to Modules
My 2 cents here is that this is flash irradiance damage. As there appear to be no burn marks on the module frames right? Jay peltz power On Sep 7, 2012, at 9:29 AM, d...@foxfire-energy.com wrote: I've seen it twice. both were DPW pole Mounts. the first time the whole array was involved (this was a few years ago). At the time, we thought it might be a disgruntled employee because no one had ever heard of such damage. I think we used box lugs and star washers on each module back then). the second just a few weeks ago. this time it seemed totally random affecting about 30% in different strings. Seems back in the broadcast industry we viewed lightening strikes as Acts of God, and focused more on repair than the whys. We install as per manufacturer's spec and NEC, and cross our fingers.. But when the Good Lord comes knocking, all bets are off. I remember pulling onto a job site once and found 80 lb chunks of chimney/ fireplace some 150ft down the driveway. Yes, the house did have lightening rods. Good Luck. db Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 ___ 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] Extensive Lightning Damage to Modules
No burn marks on the frames, modules or poles. Jeff Hudson Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of jay peltz Sent: Friday, September 07, 2012 12:59 PM To: RE-wrenches Subject: Re: [RE-wrenches] Extensive Lightning Damage to Modules My 2 cents here is that this is flash irradiance damage. As there appear to be no burn marks on the module frames right? Jay peltz power On Sep 7, 2012, at 9:29 AM, d...@foxfire-energy.commailto:d...@foxfire-energy.com wrote: I've seen it twice. both were DPW pole Mounts. the first time the whole array was involved (this was a few years ago). At the time, we thought it might be a disgruntled employee because no one had ever heard of such damage. I think we used box lugs and star washers on each module back then). the second just a few weeks ago. this time it seemed totally random affecting about 30% in different strings. Seems back in the broadcast industry we viewed lightening strikes as Acts of God, and focused more on repair than the whys. We install as per manufacturer's spec and NEC, and cross our fingers.. But when the Good Lord comes knocking, all bets are off. I remember pulling onto a job site once and found 80 lb chunks of chimney/ fireplace some 150ft down the driveway. Yes, the house did have lightening rods. Good Luck. db Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.comhttp://www.Foxfire-Energy.com/ NABCEP #092907-44 -- This message has been scanned for viruses and dangerous content by Hudson Valley Computer Serviceshttp://www.hvcomputerservices.com/, and is believed to be clean. ___ 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] Extensive Lightning Damage to Modules
Hey Larry, The four poles of ten modules in each row are each a separate string, combined at a fused DC combiner on the west most pole. A 1 inch PVC conduit runs down each pole directly to a buried hand hole box at the west pole of each row. Each conduit contains a #8 EGC along with the current carrying conductors. In the hand hole boxes the four #8 wires are irreversibly spliced to the bare #6 that is laid in and runs the length of the 39 foot trench connecting the four poles. An acorn attaches the bare #6 to a ground rod at each end. The #8 EGC at each pole is irreversibly spliced to the EGC from the rails, rack and pole, each of which have lay in lugs. The module are grounded to the rails with WEEBs. We're following Burndy's paper on how to ground DPW top of pole mounts. The #6 should not have any tight bends, it should just leave the hand hole box and go in a straight line 39 feet east in the bottom of the trench. This, combined with each pole being 5-7 feet into the ground should be sufficient grounding, I'd have thought. It's about 100 times more surface area than the average house with a single ground rod. Jeff Hudson Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Larry Crutcher, Starlight Solar Power Systems Sent: Friday, September 07, 2012 11:54 AM To: RE-wrenches Subject: Re: [RE-wrenches] Extensive Lightning Damage to Modules Hello Jeff, I am curious about the network of ground rods and #6 wire. Can you describe how the modules and mount are connected to this ground system? Are there any tight bends anywhere in the #6 wire? Are any of the poles or mounts connected to other poles/mounts before going to the ground system? Are any PV wires running between the poles before going to the combiner? As most wrenches know, lightning strikes can induce very high voltage on any nearby wire runs and that voltage is looking for a path to ground. Equipment is damaged when it contributes to that path. If the voltage was induced on the PV module frames or wire, an effective ground system will disperse it to ground. Key word here is effective. I have seen grounding systems where the installer made nice, neat and tight 90° bends in the ground wire. This is a huge mistake which can greatly diminish the effectiveness of the ground system. Larry Crutcher Starlight Solar Power Systems On Sep 7, 2012, at 8:40 AM, Jeff Irish wrote: A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I've seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We're trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 - 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we've tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.commailto:j...@hudsonsolar.com Solar Electric Systems NYSERDA Eligible PV Installer NABCEP Certified Solar PV Installer NABCEP Certified PV Technical Sales MailScanner has detected a possible fraud attempt from applewebdata
Re: [RE-wrenches] Extensive Lightning Damage to Modules
When a long circuit has surge protection at only one end, the voltage at the unprotected end of the wire will rise, by induction, during a lightning event that causes the surge protection to activate. There should be surge protection at both ends of long feeders to reduce possible damage from induced voltages. Kent Osterberg Blue Mountain Solar, Inc. www.bluemountainsolar.com t: 541-568-4882 On 9/7/2012 11:14 AM, Jeff Irish wrote: Kent, Surge protection is at the inverters, 200 feet away, on both the AC and DC sides. Nothing at the array; never thought we'd need it there. There's a 4 string fused DC combiner on the west pole of each row; no damage visible on any of them and their fuses were all ok. And yes, each pole of 10 modules is a separate DC string, 4 are combined into a DC output circuit to each of four SB7000US inverters. Jeff Hudson Solar *From:*re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Kent Osterberg *Sent:* Friday, September 07, 2012 11:56 AM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Extensive Lightning Damage to Modules Jeff, Is there any surge protection in the combiner boxes? Any damage visible in the combiner boxes? Any fuses or breakers open in the combiner boxes? Is each pole a single string of modules or multiple strings of modules? While there where undoubtedly ground currents flowing they probably didn't cause the damage in the module junction boxes. The PV module and wiring to it form a loop - often a loop with a large area in the vicinity of the module. The current from the lightning strike has a tremendous dI/dt and the changing magnetic field from it will induce voltages in any wire loop. Kent Osterberg Blue Mountain Solar, Inc. www.bluemountainsolar.com http://www.bluemountainsolar.com t: 541-568-4882 On 9/7/2012 7:40 AM, Jeff Irish wrote: A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I've seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We're trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 -- 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we've tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.com mailto:j...@hudsonsolar.com /Solar Electric Systems/ /NYSERDA Eligible PV Installer/ /NABCEP Certified Solar PV Installer/ /NABCEP Certified PV Technical Sales/ *MailScanner has detected a possible fraud attempt from applewebdata: claiming to be* HudsonSolar.com applewebdata://B5F2562A-2B67-4161-84E4-42F12DC28720/www.hudsonsolar.com 2011 NYSERDA Excellence in Quality Award | 2011 NYSEIA Award Winner | 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year | EDC Business Excellence Award for Innovation ___ List sponsored
Re: [RE-wrenches] Extensive Lightning Damage to Modules
In 2006 we installed a dozen Spire 85W modules w/clear backing in pairs as skylights. Shortly after, the building attached to the electrical equipment room, took a direct lightning strike to the wind anemometer 10 feet above the roof. Of the 12 modules four suffered damage to their diodes. Several were completely vaporized, there was nothing remaining except powder and the leads. Others had burnt diodes with leads that had clearly been very hot. Other modules were just fine, the damage seemed to be random with all 12 in series. The 4 trackers, the closest ~70 ft. away, are grounded with two spools of buried #8 bare copper and Uffer grounds in the concrete piers were untouched. Delta SS's at the tracker discos and in the inverter room were unaffected which I thought was odd. 5 Sunny boys 2 Sunny Islands in the same room were toasted. Our only experience with lightning. Jim Duncan North Texas Renewable Energy Inc www.ntrei.com http://www.ntrei.com/ NABCEP PV 031310-57 TECL-27398 nt...@1scom.net 817.917.0527 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jeff Irish Sent: Friday, September 07, 2012 9:41 AM To: RE-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Extensive Lightning Damage to Modules A customer of ours has recently suffered lightning damage to 31 out of 160 top of pole mounted modules. This is the first time in 10 years that I've seen modules damaged by lightning. Lots of inverter GF fuses and a few inverters, but never modules. We're trying to determine if it was caused by the lightning flash irradiating the modules or ground currents. The array consists of 16 DPW top of pole mounts with 10 modules each, arranged in a square of 4 poles E-W and 4 rows N-S. The poles are 13 feet center to center E-W and the N-S row spacing is about 50 feet. The poles are 6 inch galvanized Technoposts, augured 5 - 7 feet into the firm ground, connected with a network of about 160 feet of bare #6 copper and at least 8 copper plated ground rods. Altogether we have about 130 square feet of bare metal surface area connected and buried in the ground at and around the array. The customer saw lightning strike just after dawn a few weeks ago a couple hundred feet to the southwest where it also destroyed two utility pole mount distribution transformers and ran along the utility wires 100 feet south of the array. The inverters are 200 feet NW and suffered no damage. The array and modules look totally fine, except some of the J-boxes are deformed from heat. Opening the J-boxes shows varying levels of damage to one or more diodes, from discoloration to being broken and cracked open. The odd thing is the pattern of damage (we've tested all the modules individually for Voc and Isc). Only modules in the south row of 4 poles are damaged, and the damage is concentrated on the modules closest to the ground; modules higher up in the air appear OK. Also, damage is less frequent as you move east, away from the direction of the strike. If it was caused by ground currents, why would the current want to go up the poles, why only the southern row of poles, and why damage more modules closer to the ground and not those at the top? Is it possible a flash near the ground irradiated the modules causing a current spike and the southern row shielded the other rows from most of the flash? Anyone have experience with this? Jeff Irish, PE President Hudson Solar 13 Hook Road Rhinebeck, NY 12572 T.845.876.3767x110 F.845.876.3912 j...@hudsonsolar.com Solar Electric Systems NYSERDA Eligible PV Installer NABCEP Certified Solar PV Installer NABCEP Certified PV Technical Sales HudsonSolar.com applewebdata://B5F2562A-2B67-4161-84E4-42F12DC28720/www.hudsonsolar.com 2011 NYSERDA Excellence in Quality Award | 2011 NYSEIA Award Winner | 2009 Best of the Hudson Valley | 2008 SunPower Dealer of the Year | EDC Business Excellence Award for Innovation ___ 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