I have an array that has been up and running with no problems for 6 months. The array includes 58 Sanyo HIT 220 watt N-Series modules, 13 of which are on Enphase M210 and the rest in strings to (2) Power One transformerless (ungrounded) inverters. This week one of the Power One inverters shows a RISO error, indicating a connection to ground on one of the current carrying conductors.
I went out yesterday to look at the array, thinking these were the three potential issues (in descending order of likelihood): - animal damage to the wires (though there are no trees near the house at all) - contractor damage to wires (no work has been done on roof or attic since we were there) - inverter problem I found one inverter input that shows continuity to ground at the DC disconnect (which indicates the inverter is doing just what it is designed to do!). I opened the Soladeck on the roof (which is where the PV output circuit/PV wire is transitioned to wire in conduit run through the house), disconnected the connection, and found the PV output circuit itself shows continuity to ground. I inspected the array carefully, and all wires are strapped securely off of the roof and out of sight, everything looks just as I left it 6 months ago. I've dealt with significant animal damage before and know what to look for. My question: I can lift each of these 8 modules in the string up and check the wires carefully, but outside of that being a hidden cause, is it possible that one of the modules itself is shorting to ground? If so, how do I check that and what else will I need to do to prove that to the distributor for warranty replacement? So far I've used the continuity tone on the volt-meter for testing the short to ground. I have a megger but it is new, so, therefore, is my knowledge of how to use it... Thanks in advance. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green [email protected] 763-438-1976 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
