Parallel conductors

[Rolando O.]

Can 3 phase parallel conductors be run in one conduit, derating considered?
For example, 8 #350 in a 4" conduit to feed a 600 A meter room

 

[texie]

Yes, you can but it won't work in your case. You have 6 current carrying conductors. Derate to 80% and you only have an ampacity of 560.

 

[texie]

This is a case of if your calculated load is less than 560 you could use the next size up rule. But most AHJs would want formal calcs to prove it.

 

[LarryFine]

Yes.

Added: I was answering the single-conduit question, not the current math.