[RE-wrenches] PV panel backing

[Jerry Shafer]

Beware sometimes helping someone get by with a repair can backfire on the
guy just trying to help ya i know it will never happen to you but
On Sep 1, 2014 10:59 AM, "Martin Herzfeld" <findsolar at herzfeld.org> 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 <solareagle at solareagle.com> wrote:
>
> Subject: [RE-wrenches] PV panel backing
> To: "RE-wrenches" <re-wrenches at 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 at 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 at 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
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140901/c4ffdcbb/attachment-0002.html>