Service conductors for 1600A service at 480V

[Smart $]

Just sticking in my 0.02; but wouldn't the harmonics from a 3ph or L-L drive (without a neutral) still generate harmonics on the 3ph-4W system?

It would seem that harmonics could be present on the 3ph-4W neutral system (service); albeit possibly reduced due to taking into account the canceling effect from other loads/circuits on the same board; but still enough that the neutral would need to be considered current carrying.

Harmonics would definitely be present on the system and the circuit... but not on the neutral. IMO, there'd be no reason to count the neutral as a current-carrying conductor.

 

[jim dungar]

Just sticking in my 0.02; but wouldn't the harmonics from a 3ph or L-L drive (without a neutral) still generate harmonics on the 3ph-4W system?

See Post #32

No matter how large the harmonic content, a non-linear load like a rectifier bridge or a luminaire with ballast which only connects to the three ungrounded conductors (three phase) or the two ungrounded conductors (single phase) cannot put any current on the neutral.

 

[mivey]

I think the 10' came from someone(s) trying to parallel concepts for this and 310.15(A)(2) Exception... but I have no proof. :roll:

Could be but I don't recall as it has been a few years. I would have to research it and I don't feel like it.