Thanks everyone for your insightful replies, have passed them on to the customer with comments. He only wants to try and get another 6 mo. out of the panel until he can afford to replace it; and as always there are circumstances to consider. Unfortunately his shop burned due to arson and no insurance coverage so money is tight.
Ron On Sep 1, 2014, at 4:30 PM, Ray Walters <r...@solarray.com> wrote: > I've done patch jobs on little 12 v systems, and had them hold up for many > years, but I concur, I wouldn't try that at higher PV voltages. > Silicon sealant actually is slightly conductive, at least according to other > Wrenches when this subject came up several years back. > R.Ray Walters > CTO, Solarray, Inc > Nabcep Certified PV Installer, > Licensed Master Electrician > Solar Design Engineer > 303 505-8760 > On 9/1/2014 2:43 PM, Martin Herzfeld wrote: >> >> I concur with Dan. Unless a controlled environment, a patch job on a module >> with a customer is wrong on so many levels. >> >> Martin Herzfeld >> California Solar Contractor License #833782 >> Trenching Contractor, Pole Installation & Maintenance, Instrumentation >> >> UL Certified PV Installer #17, OSHA 30 >> Principal Contract Solar Technical Inspector >> OSHA-Authorized Construction Trainer >> CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG >> Project Contractor & Consultant >> >> Telephone & Text: 510-243-0190 >> >> Ron, >> >> It's been my experience the only adhesives that work reliably on PV >> backsheets are those designed for the purpose, such as Dow 804 et. al.. >> Substances such as silicone sealant, tool polymerics, and others will appear >> to be suitable when first applied, but they eventually peel loose over a >> period of 1-5 years. >> >> Issue #2: Heat of sufficient temperature to melt the backsheet may also have >> been hot enough to affect solder joints on and among the cells. >> Crystallized solder connections will conduct current, but are more >> resistive, and eventually will degrade due to heating and cooling, leading >> to overheating and eventual failure. Then too there's a possibility of >> micro-fractures created in the cells due to the heat, which take time to >> become apparent, but will also cause a PV module to quit working .. or at >> least quit working at its rated specifications. >> >> Issue #3: When PV are manufactured, the layers at a minimum are >> manufactured from tempered glass, EVA, cells and buss, EVA, then the >> backsheet (tedlar, kevlar, etc.), in that order. The module is assembled >> under conditions of heat and vacuum. With the backsheet melted, the >> environmental integrity of the laminate has been compromised, allowing >> ambient humidity into the PV. While it may be functional now, long-term >> prospects for continued proper operation are questionable at best. >> >> Unless there's a pressing reason to try to salvage the module, it's better >> to replace it. >> >> Dan Lepinski >> >> -------------------------------------------- >> On Sun, 8/31/14, Ron Young <solarea...@solareagle.com> wrote: >> >> Subject: [RE-wrenches] PV panel backing >> To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> >> Date: Sunday, August 31, 2014, 6:32 AM >> >> Hello Wrenches, >> >> I have an installation of 165w PV on a pole mount that was exposed to a fire >> from the rear when the customers shop burned. 6 of the 10 panels survived >> with only replacement of the MC4 plugs required but one of the panels that >> is still functioning had the rear coating melted off. The cells and >> electrical grid still function. Can anyone recommend a replacement coating >> that may salvage this panel for a few more years. I know if left exposed it >> will soon deteriorate but am wondering if some kind of commonly available >> non conductive rubberized or latex type of coating might do the job? >> >> Ron Young >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address:RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive:http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org >
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