Wire gauge for multiple Enphase batteries

Z

Zee

Senior Member
Location
CA
When wiring 4 Enphase IQ 5P batteries in a single circuit fed by a 2p80A breaker, do you run 4 AWG Cu wire to all 4 batteries, or can you run #4, then #6, then #8, and finally #10?

If the 2nd is allowable, what allows it?

(A single IQ5P battery goes on a 2p20A breaker. 16A cont. Rated Output)
 
The conductors are all protected by the 80A CB so they all have to be rated for 80A in a fault condition. If you were sizing just to the load then you could reduce the conductor size.
 
I'd agree, I do not see anywhere from Enphase documents/enhase university allowing smaller conductors on downstream batteries. You are allowed to do this on solaredge systems per manufacturer installation instructions- most AHJ's would be cool with that. But totally different system. I'd say to make it happen here you'd need documentation from Enphase, I haven't reached out, you could ask, but probably would just do #4s all the way through to be safe.
 
Zee said:
When wiring 4 Enphase IQ 5P batteries in a single circuit fed by a 2p80A breaker, do you run 4 AWG Cu wire to all 4 batteries, or can you run #4, then #6, then #8, and finally #10?

If the 2nd is allowable, what allows it?

(A single IQ5P battery goes on a 2p20A breaker. 16A cont. Rated Output)
Click to expand...
Maybe use a small AC combiner panel with 4x2P20A and 12AWG runs where the batteries are located, and 4AWG from main lug to the 80A breaker in the upstream panel?
 
If a fault occurred on a conductor at the end of the line, the only thing protecting that conductor would be the 80A breaker, so the conductor would have to be rated appropriately, as would the grounding conductor.
 
solarken said:
Maybe use a small AC combiner panel with 4x2P20A and 12AWG runs where the batteries are located, and 4AWG from main lug to the 80A breaker in the upstream panel?
Click to expand...
Generally not necessary and wouldn't save a meaningful amount of money, if any. Might make sense if the batteries had to be spaced far apart from each other for some reason.
 
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solarken said:
Maybe use a small AC combiner panel with 4x2P20A and 12AWG runs where the batteries are located, and 4AWG from main lug to the 80A breaker in the upstream panel?
Click to expand...
Good idea, but these are most efficiently installed when "daisy chained" with short nipples going between each. So #4 it is.
The Enphase IQ5P batteries have a comm. wire that daisy chains easily and the wire terminals for teh hot wires are all set up for the hots to be landed that way also.

I just had a brainfart somehow, and thought i don't #4. :p We solar guys think we're working with HUGE wire if its bigger than #10!:rolleyes:
 
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(fortunately some of the "inter-battery" nipples we installed are 1" already...................... and the rest are 3/4"........ which i can cram the wires thru using the "less than 24" long nipple can be filled at 60%" rule.
 
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