Have you measured the current of each string simultaneously while the issue was happening? Have you verified correct polarity on each string?
Roy Rakobitsch NABCEP Certified Small Wind Installer® Certified Advanced Tower Climbing, Safety & Rescue Wind/PV Design Engineer Windsine LLC 631-514-4166 www.windsine.org On Sep 7, 2016 4:45 PM, "Matt Partymiller" <m...@solar-energy-solutions.com> wrote: > Wrenches, > > One of our systems is having an issue I have not encountered before where > the inverter switches between nighttime mode and interconnection every few > seconds. I am hoping for some technical wisdom from the community. > > We have an array of 20 TrinaSmart modules in two strings of 10. The array > is connected to a Solectria 3.8 kW inverter. The conduit run is simple, > all four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the > Solectria inverter where the conduit switches to 1" LFMC before entering > the inverter. The run is about 20', straight down the side of the wall > before hitting the inverter. A 600V jacketed communications wire was also > in the conduit but has since been removed and run separately. > > Our inverter is starting up, running for a few seconds, giving a low > voltage error, briefly showing nighttime mode, then going into startup > mode again. Solectria was gracious enough to send us a new inverter but > we have the exact same issue. They tell us their error codes (266, 274) > indicate 0 volts. The transition between low voltage error and startup is > almost instant. Basically we have 20 seconds of start up, 5 seconds of > run, 5 seconds of error then repeat. This is not a grid problem, the > identical system next door works fine. > > In the process of troubleshooting, our technician pulled all four homerun > wires out of our conduit and meggered them. They all tested fine so he > connected to the inverter. The inverter worked fine. The technician > verified grounding of the array and conduit, pulled new homeruns back > through the conduit, and reconnected to the inverter. He had the same > error as before. > > He connected each string separately to the inverter by removing the string > fuses. Either string will operate fine independently. With string one in > conduit and either homerun of string two in conduit (but not both) the > inverter operates fine. With string two in conduit but string one outside > of conduit, the inverter does not operate. > > I was certain the error had something to do with homerun roof wiring so I > went out with the technician and removed and checked pretty much every > module. Everything appears fine, all connections solid, all homeruns have > been remade at least once at this point. Now I am stumped and lack the > technical knowledge to diagnose the problem. I would be extremely > grateful if an esteemed wrench can provide technical support/advice. > > Thanks, > > Matt > > > > > Matthew Partymiller > Solar Energy Solutions LLC > (877) 312-7456 > m...@solar-energy-solutions.com > > > _______________________________________________ > 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
