2 of 4 Solar panels aren't working

[lnanne]

This is probably not something you can troubleshoot by forum but it's worth a try!

We have 4 Zamp 160 watt panels and a xantrex c60 controller installed by a company in January 2017. By process of elimination (covering the panels with tarps) we have determined that 2 of the 4 panels aren't putting any amps into the batteries. The other 2 we're putting in approximately 7 each. We only know this because of our Trimetric monitor (which also shows that the batteries are at 70%). The batteries are 4 golf cart interstates at 210 each.

We're trying to get hold of the installers for trouble shooting but while we wait, has anyone had that happen and what was the cause?

We did check the volts coming out of the panels with a meter and that looked fine (18 or so if we recall correctly).

Thanks for any thoughts on this!

[cruzbill]

You can check each panel's output individually, that's what a tech will do. Each panel has two wires, you'll need a MC4 disconnect tool (cheap) to undo the connections. Check the + to - at each panel, should be about 22v or so. Your MC4 connectors may have a fuse in them, of course check that. Then, from the panels, just follow the wires to check for fuses or a 'disconnect' of some type. Follow the wires to the controller, you'll learn a lot! Solar panels either work or they don't, so the problem (unless the panels have cracked glass or some other obvious issue, burned wires) usually is at the MC4 connectors.

Good luck!

[CountryFit]

i assume they all are connected in parallel. correct?
first, look for the combiner box. remove the cover. some have fuses in it so check that.
if no fuse issues and no voltages from the two non-power panels, then you know the gremlin(s) is either in the mc4 connectors or the panel selves. it's only 6 months since install, the vendor should take care of them.

[lnanne]

Thanks all for your advice and we will pursue them this weekend. Yes, they all 4 are parallel and the two panels that aren't working are wired together to go to the solar controller so that makes us think it's further down the line. What fun! We'll let you know when we have it resolved!

[lnanne]

Well, after testing multiple points before and after connectors we found that it was after the last connector on the roof and discovered there was a splice point with tape wrapped around it so it was either that or coming into the solar controller because we took apart both trying to test them and now they work after putting them back together. Arghh! Thanks again for the responses!