I have an array of 3x150W panels wired in parallel to my MPPT 100/50 controller. On a clear sunny day with no shading and clean panels, I've never seen the controller show more than 200W. What's the best place to begin to troubleshoot?
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PV Array Low Yield
Well, if you're in Finland I'd call this a stellar result in winter. I got 15W from 320Wp two weeks ago ;)
That's in Maine, USA (around 40* north latitude) in July. I'm topping out at 80W on a clear day at 23* N in the Bahamas these days.
Do you have sufficient load (demand for current) eg. discharged battery so that the MPPT is not throttling the panel?
Warwick, this is with battery voltage around 12.2.
@bob ralpherson, the fault seems to be on the PV side of things, so I'd suggest either getting out the multimeter and checking volts and amps at each panel or, alternatively, just hooking each panel up to the controller individually and making notes of how each panel performs. It sounds to me like you may have at least 1 faulty panel and, assuming that these are like-kind panels, it should be relatively easy to isolate the fault this way as well as get a good idea of the realistic output of each panel individually so that you're better equipped to calculate what you should be getting from all three together.
It's very possible that the fault is within a bad crimp or connector (it's not at all uncommon to see a poor connection inside an MC4 connector) that may be causing the issue, or if you have inline fuses on the array -which, given that you're at 3 panels in parallel, you should have- and that one of the fuses is blown. Depending on how things are connected, hooking each panel up to the controller separately may or may not fully isolate the problem, but if it's feasible for you to do, it's a good place to start.
Thank Justin. That’s a good idea. I’ll give that a shot! Now I just need to figure out how to pull apart these MC4 connectors...
@bob ralpherson they're a pain, and in fact there's a special little tool sold for doing that, but if you haven't figured it out already, you can usually manage with a pair of needlenose pliers to compress the two locking pins on each side and then pull/sort of pry them apart.
