Single Conductor or Two in Parallel: 3/0 or 500 kcmil for 400A

[kwired]

IIRC, the "skin effect" at 60Hz is something like a quarter inch, so unless you're using rather large conductors it's won't matter much.

4 AWG is a little under 1/4" 3 AWG is a little over.

Some will say those are not large.

 

[LarryFine]

4 AWG is a little under 1/4" 3 AWG is a little over.

Some will say those are not large.

I believe the 1/4" refers to depth, so you would use the radius, not the diameter.

Thus, the conductor would have to exceed 1/2" diameter for it to become significant.

 

[kwired]

I believe the 1/4" refers to depth, so you would use the radius, not the diameter.

Thus, the conductor would have to exceed 1/2" diameter for it to become significant.

Makes sense, that puts you to 500KCM.