I have a client that has a 34.5kV 3-phase drop from the utility and several 575VAC 3-phase (secondary) transformers.

Generally speaking, is the secondary of these transformers normally delta (3-phase/3-wire) or Wye (3-phase/4-Wire)? OR is it site dependent on how they are wired?

I've not worked with 575VAC before and wanted to know if anyone has any guidance on how 575V is normally done.

 

Willy... 575V is not a USA Std, but it is about 5% lower than 600V, which is a Std! And, 575V is equal to the 5% tap on step-down transformers! Furthermore, Xfmr mfg's will furnish a 575V secondary when requested! I suggest that you contact one for their knowledge!

There are pockets of areas in the US and Canada using it for 3-wire installations!

Reur query on 3W-Delta, or 4W-Wye...
The latter design would result in a phase-to-neutral voltage of about 330V!

FYI... many "Oil-patch" installations use 3P, 3W, 830V!

Regards, Phil Corso