paralleled conductors

[101010]

I have a 400 amp 480v service .From pole to ct is 60 feet. Would you guys run 1 set of 600 mcm or two sets of 4/0. There is only 1- 4" pvc

 

[masterinbama]

I would use the 600's. The extra time and effort to set up and pull 4 more wires is not worth it. IMHO

 

[benaround]

I have a 400 amp 480v service .From pole to ct is 60 feet. Would you guys run 1 set of 600 mcm or two sets of 4/0. There is only 1- 4" pvc

Depending on 3 wire or 4 wire service you would need to derate the 4/0's to 80% or 70%

neither add up to 400amps.

 

[augie47]

Depending on 3 wire or 4 wire service you would need to derate the 4/0's to 80% or 70%

neither add up to 400amps.

What am I missing. 4/0 THHN/THWN-2 260 x .8 = 208 x 2 = 416

 

[chris kennedy]

I have a 400 amp 480v service .

I'm surprised no one has mentioned one set of 500's. What is the calculated load? BTW that is what I would pull.

 

[bob]

What am I missing. 4/0 THHN/THWN-2 260 x .8 = 208 x 2 = 416

You are correct as usual.

 

[iwire]

I priced out one set of 600 copper in one raceway vs two sets of 3/0 copper in two raceways and the two sets was cheaper by a large factor.

Labor was close to the same as the runs would have been mostly straight on a flat roof.

I needed at least 400 amps.

 

[augie47]

Bob, I know I'm going to regret asking this as you are always sharp as a tack, but what about 310.15(b)(2)(c) ? Not a factor ?

 

[iwire]

but what about 310.15(b)(2)(c) ? Not a factor ?

It was and I could have explained myself better when I said I needed 400 amps.

I started with 100 F and went with the 40 F adder. along with the double 125% that PV systems require, I can not remember what the 'real' load was but it was not very high at all.

 

[benaround]

What am I missing. 4/0 THHN/THWN-2 260 x .8 = 208 x 2 = 416

Sorry Gus I was using the 75deg column, but, to save face just a little if it was a 4 wire

system @ 70% derating = 364amps.

 

[augie47]

It was and I could have explained myself better when I said I needed 400 amps.

I started with 100 F and went with the 40 F adder. along with the double 125% that PV systems require, I can not remember what the 'real' load was but it was not very high at all.

I figured you had it covered, sorry

 

[augie47]

Frank, not challenging you, and you are correct, curious, how often have you seen a service with a major portion of the load nonlinear ?
That's not intended to be "smart alec", but I often wonder. I don't recall ever seeing one.

 

[don_resqcapt19]

Sorry Gus I was using the 75deg column, but, to save face just a little if it was a 4 wire

system @ 70% derating = 364amps.

As long as the load calc showed a load of 364 amps or less, you would still be ok.

 

[benaround]

Frank, not challenging you, and you are correct, curious, how often have you seen a service with a major portion of the load nonlinear ?
That's not intended to be "smart alec", but I often wonder. I don't recall ever seeing one.

Gus,

That has got to be the nicest way I have ever been told I was wrong, and I am wrong

so much for saving face , and thanks

 

[bob]

It was and I could have explained myself better when I said I needed 400 amps.

I started with 100 F and went with the 40 F adder. along with the double 125% that PV systems require, I can not remember what the 'real' load was but it was not very high at all.

What does that mean?

 

[Pierre C Belarge]

I'm surprised no one has mentioned one set of 500's. What is the calculated load? BTW that is what I would pull.

That is typically what is installed in this neck of the woods. Most 400A services around here do not have much load to them.