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EMD360's avatar
EMD360
Explorer
Aug 09, 2021

Question about solar combiner box.

I’m designing a small solar system for the RV roof. I have room for 3 100 watt panels which I have already ordered from Northern Arizona Wind and Sun. I know this company from when I lived in Arizona and have confidence they stock quality materials at reasonable prices. The panels are 52x20 so they can be shipped UPS.
I can’t wire 3 panels in parallel and I want the panels to be shade tolerant. I’m considering wiring them individually to a combiner box on the roof. I can’t find information about this wiring setup. I assume it would be the same as using a combiner box for more than one string. Each panel would be its own string. So has anyone wired their panels like this? Does it make sense to keep them as separate “strings”?
  • A combiner is just putting all three in parallel how ever you do it and it takes more wire. There are all types of connectors to hook up anyway you want. I changed to series and that allows for a smaller wire hookup to your controller. You need a higher voltage input controller and there are plenty that allow 100 volt input. MPPT is what you want and it gives better charging.
  • Series wiring is much easier. Bypass diodes make them shade tolerant -not that you want to be in the shade much.