Just to add, l had a lab and l did testing on connectors, we found that most of the aec issues were under low light. This appeared to be when iradiance was low and once the irads went up the issue was less likely, this was because the Male-female contact was not tight enough and under lower power it would arc instead of heating up and expanding. I used a IR Camera but could see little change due to the plastic. Then l used an IV curve tester and shaded partially shaded the module after several repeat testing the connectors got warm. I would suggest making your own connector pull out tool to check the contact pressures. This is where you may find your problem components. It appears that early am testing had lower volts and the inverter pushed the current up and causes the loose connector to fail due to the lower volts. This testing was done both in the field 1/2 meg and lab testing results were very close. The modules used for testing were Trina and the field inverters were ABB and Fronius Sorry for the long note Jerry
On Wed, Sep 4, 2019, 2:52 PM Steven Lawrence <lawrenceste...@gmail.com> wrote: > Everyone, > > Just to add to this, I've seen multiple melted connectors that couldn't be > traced to anything other than mixing manufacturers. I've seen some > connectors where you can clearly seeing arcing on the pin itself and > nowhere else. The crimps and the housing were fine. I've postulated it > had to do with slightly different metals expanding/contracting at different > rates. I've made it a very hard rule at my company to never mix > manufacturers of connectors. When we order modules, we specifically have > the PO call out the manufacturer of the connector (can't just be "MC4 > compatible"). Typically we order that same brand of connectors, but > sometimes we end up getting 6" jumpers made by a harness company (there are > some connectors out there that can only work with #12 wire. Can't use them > on #10 homeruns). It's drastically cut down on the number of melted > connectors. We've averaged maybe 1 or 2 on 6MW projects over a year with > this hard requirement versus 100+ we had on a 1MW rooftop project that > mixed multiple manufacturers. > > Steven Lawrence > _______________________________________________ > 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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