Thanks Dave, We have installed many systems and we only had this problem with Sanyo modules and we had a rash of these crop up about the same time-frame and the issue only affected part of the array. Panasonic denied our claim because they stated it was a lightning strike. The cause is inconclusive in my opinion.
Thanks On Thu, Jul 6, 2017 at 4:25 PM, Dave Angelini Offgrid Solar < [email protected]> wrote: > The diode check on a dvm is useful but may not show a diode breaking down > at higher voltage. Yes lightning can open up the tabs or connecting foil > inside a solar panel. It can do alot more than that! One of the best > reasons for using an SPD at the array is also preventing the latent damage > that can show up later. A really close strike and prayer may help but I > doubt it :) > > Dave Angelini Offgrid Solar > "we go where powerlines don't" > http://members.sti.net/offgridsolar/ > e-mail [email protected] > text 209 813 0060 > > > > Did you use the Diode Test function on the meter? If the diode is good > > you > > should see around 0.4-0.8 V in the forward bias, and OL in reverse. If > it > > is bad (open) you'll get OL in both directions, and if it is shorted > > closed > > you'll get the 0.4-0.8 V reading in both directions. > > > > Shorted closed would be the failure mode that would indicate an > > always-closed diode providing a permanent bypass path and thus a drop of > > 25% of voltage per bad diode (or set of paralleled diodes). (These have > 4 > > diodes right?). > > > > > > > > > > Brian Mehalic > > NABCEP Certified Solar PV Installation Professionalâ„¢ R031508-59 > > 520.204.6639 > > > > Solar Energy International > > http://www.solarenergy.org > > > > SEI Professional Services > > http://www.seisolarpros.com > > > > > > On Thu, Jul 6, 2017 at 4:31 PM, Taiyoko Sadewic < > > [email protected]> wrote: > > > >> Hi Wrenches, > >> We were installing Sanyo HIT modules back in 2006-2007 and in 2014 we > >> had > >> a rash of bad Sanyo modules. The modules had distinct voltages below the > >> good modules ie 50% or 75%. Sanyo at the time (now Panasonic) indicated > >> that it was a bad diodes from a lightning strike not covered by > >> warranty. > >> > >> I finally got around to checking that out. I identified the purportedly > >> bad diode in one module (four per module) that was performing at 75% and > >> removed it. The diode appears to be fine using an ohm meter. Is that a > >> valid test? > >> > >> Anyone else have similar findings or experiences with this? Could > >> lightning blow apart the tab ribbons inside of the module? > >> > >> Thanks > >> > >> -- > >> <http://www.PositiveEnergySolar.com> > >> Taiyoko Sadewic > >> Employee-Owner > >> NABCEPâ„¢PV Installation Professional > >> NABCEPâ„¢Technical Sales > >> 3209 Richards Lane | Santa Fe, NM 87507 > >> cell 505.570.0137 <505.699.9032> > >> [email protected] <[email protected]> > >> www.PositiveEnergySolar.com > >> <http://www.positiveenergysolar.com/> > >> <http://www.facebook.com/positiveenergysolar> > >> <https://twitter.com/PositiveESolar> > >> <https://plus.google.com/+Positiveenergysolar> > >> <https://www.youtube.com/user/PositiveEnergySolar> > >> <https://www.positiveenergysolar.com/blog/blog/> > >> <https://www.positiveenergysolar.com/contact/refer-a-friend/> > >> <https://www.bcorporation.net/community/sunpower-positive-energy-solar> > >> <http://www.solarreviews.com/installers/positive-energy-solar-reviews/> > >> > >> _______________________________________________ > >> List sponsored by Redwood Alliance > >> > >> List Address: [email protected] > >> > >> Change listserver email address & settings: > >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > >> > >> List-Archive: http://www.mail-archive.com/[email protected] > . > >> 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: [email protected] > > > > Change listserver email address & settings: > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > > > List-Archive: > > http://www.mail-archive.com/[email protected]. > 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: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: http://www.mail-archive.com/[email protected]. > org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > -- <http://www.PositiveEnergySolar.com> Taiyoko Sadewic Chief Financial Officer | Employee-Owner NABCEP™PV Installation Professional NABCEP™Technical Sales 3209 Richards Lane | Santa Fe, NM 87507 cell 505.570.0137 <505.699.9032> [email protected] <[email protected]> www.PositiveEnergySolar.com <http://www.positiveenergysolar.com/> <http://www.facebook.com/positiveenergysolar> <https://twitter.com/PositiveESolar> <https://plus.google.com/+Positiveenergysolar> <https://www.youtube.com/user/PositiveEnergySolar> <https://www.positiveenergysolar.com/blog/blog/> <https://www.positiveenergysolar.com/contact/refer-a-friend/> <https://www.bcorporation.net/community/sunpower-positive-energy-solar> <http://www.solarreviews.com/installers/positive-energy-solar-reviews/>
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