Forum Discussion
westend
Mar 09, 2016Explorer
Roof top combiner box made with a 1 1/2" plastic LB and two terminal strips:

MC4 cable entry of combiner box (I filled the entry rubber insert with silicone after pulling the MC4 through):

I ran #4 AWG from these terminal strips to a manual circuit breaker and then to the controller. I used the 1 1/2" exit of the LB and piped the cables down but a user that wishes to not pipe cables could use a 4" plastic box and do the same thing with a smaller exit hole, mounting the box directly to the roof. Those solar combiner boxes are nice but not $50 more nice.

MC4 cable entry of combiner box (I filled the entry rubber insert with silicone after pulling the MC4 through):

I ran #4 AWG from these terminal strips to a manual circuit breaker and then to the controller. I used the 1 1/2" exit of the LB and piped the cables down but a user that wishes to not pipe cables could use a 4" plastic box and do the same thing with a smaller exit hole, mounting the box directly to the roof. Those solar combiner boxes are nice but not $50 more nice.
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