Quote Originally Posted by david luchini View Post
I think you are looking at a situation where a building owner is trying to fill one of his empty spaces, like a strip mall or something similar.

The tenant says he needs 400A at 208/120V...the existing building service is 480/277V.

If the tenant has no need for 480/277, the simple solution would be to bring the 200A, 480V feeder to the space and supply a 112.5kVA transformer to a 400A, 208/120V panelboard.
Huh. Somehow I must have missed the statement about having the 480V service... I was reading it from my phone at that time, I guess I just missed it (or it was edited after I posted that).

I agree. If the requirement was for 400A at 208V, you can't get that from a 75kVA transformer, so therein lies the problem.

By the way, you can't get 400A from a 112.5kVA either, it needs to be 150kVA minimum.