3 phase 4 wire 120/208v 200A

4965 Views 12 Replies 7 Participants Last post by electricsugarman, May 6, 2014

electricsugarman

Discussion Starter · May 5, 2014

I am wiring a 3 phase 4 wire 120/208 200A 42 circuit breaker panel tomorrow. I am going to use 3/0 copper and #6 for ground. I then started second guessing myself about the wire size. The neutral will not be counted towards the ampacity because it is only drawing the unbalance current. I dont have to upsize my 3/0 because of the more than 3 wire in a conduit rule right? Everything is going to be 120v single phase loads. Only using 14 circuits. As long as I balance my phases, I shouldnt have a problem with inspector.

thanks for your input.

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1 - 13 of 13 Posts

Awg-Dawg

· #2 · May 5, 2014

electricsugarman said:
I am wiring a 3 phase 4 wire 120/208 200A 42 circuit breaker panel tomorrow. I am going to use 3/0 copper and #6 for ground. I then started second guessing myself about the wire size. The neutral will not be counted towards the ampacity because it is only drawing the unbalance current. I dont have to upsize my 3/0 because of the more than 3 wire in a conduit rule right? Everything is going to be 120v single phase loads. Only using 14 circuits. As long as I balance my phases, I shouldnt have a problem with inspector.

thanks for your input.

Sounds good to me.

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ponyboy

· #3 · May 5, 2014

If you follow the guidelines of the NEC there's little you could do to mess it up. Even if you didn't balance the loads.

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darren79

· #4 · May 5, 2014

ponyboy said:
If you follow the guidelines of the NEC there's little you could do to mess it up. Even if you didn't balance the loads.

That could totally mess it up since the OP is in Canada:laughing:

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LGLS

· #5 · May 5, 2014

darren79 said:
That could totally mess it up since the OP is in Canada:laughing:

Yup. Tomorrow I can look forward to a beautiful moonrise...

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ponyboy

· #6 · May 5, 2014

darren79 said:
That could totally mess it up since the OP is in Canada:laughing:

Good point. Change NEC to CEC and the sentiment remains

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wcord

· #7 · May 5, 2014

ponyboy said:
Good point. Change NEC to CEC and the sentiment remains

Another few code cycles and CEC will be reduced to NEC standards, SE cable, no panel divider, NMD ( Romex for you guys) entering panels with no connectors,

. Maybe even no need to have a license to call yourself an electrician

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electricsugarman

Discussion Starter · #8 · May 6, 2014

So, any canadians (LOL) see any problems with this setup?

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l0sts0ul

· #9 · May 6, 2014

No, other than you're calling for a Grounding conductor, not a bonding conductor...

Also, Im assuming you're counting the neutral conductor in your pipe fill, and you didn't mention if this is a service, subservice, or sub panel.

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electricsugarman

Discussion Starter · #10 · May 6, 2014

Sub panel, using 2.5" nipple between disconnect and subpanel

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l0sts0ul

· #11 · May 6, 2014

Is the nipple rigid steel with 4 lock nuts and bushings?

Either way, I would run a bonding conductor to be safe, but thats all it is.... an equipment bond.

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