400amp commercial service

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jimmyjohn

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Location
Tulsa, Oklahoma
I have a commercial service where I am installing a 400amp service to.

I was told 600MCM is what I needed to pull, is that correct? If so what size wire should I use if doing it in parallel?

If I run it parallel, can I put the wire in the same conduit if it is just a 6'' conduit run from the meter can to the panelboard (stub)?
 

charlie b

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Location
Seattle, WA
Occupation
Electrical Engineer
A 500 MCM copper THHN is only good for 380 amps. If you have performed a formal load calculation and if the results were 380 or lower, then you can use the 500's. But that is not likely to be the case. So 600's is one option. A pair of paralle 1/0's will give you an ampacity of 520, and that is the smallest size you can use to get a total of 400 or higher. You can put them in one conduit, even if the run were longer than 24 inches. The 90C rating of 1/0 copper is 260. Putting 6 current-carrying conductors in one conduit, and derating to 80%, gives you an ampacity of 416.

Welcome to the forum.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
A 500 MCM copper THHN is only good for 380 amps. If you have performed a formal load calculation and if the results were 380 or lower, then you can use the 500's. But that is not likely to be the case. So 600's is one option. A pair of paralle 1/0's will give you an ampacity of 520, and that is the smallest size you can use to get a total of 400 or higher. You can put them in one conduit, even if the run were longer than 24 inches. The 90C rating of 1/0 copper is 260. Putting 6 current-carrying conductors in one conduit, and derating to 80%, gives you an ampacity of 416.

Welcome to the forum.

Don't you mean 4/0 Charlie?
 
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