Another transformer question

[Smash]

I have a 3ph 240V 4 wire high leg delta incoming service. I’m hooking up a 45kva step up 480V wye transformer for a compressor. Do I simply feed transformer with the 3 phase delta 3 wires only ? Even if I have a neutral available. Then ground the X0 terminal and size it per my load that now is my equipment neutral. Obviously I’d supply additional egc and terminate all in transformer ground bar. Including base and structured steel.

 

[infinity]

If your using a delta/wye step up transformer your 240 volt primary would be 3 conductors, the wye secondary would be 4 conductors with 3 phases legs and a neutral.

 

[LarryFine]

The transformer primary should be connected as a delta load; if it has a neutral, leave it unterminated.

If your transformer's secondary has a neutral, you should bond and ground it as you would any new neutral.

 

[Smash]

Pretty much what I figured. Back of my mind I’m thinking why not just give your wye load your incoming delta neutral. Just like to be sure ty

 

[electrofelon]

I have a 3ph 240V 4 wire high leg delta incoming service. I’m hooking up a 45kva step up 480V wye transformer for a compressor. Do I simply feed transformer with the 3 phase delta 3 wires only ? Even if I have a neutral available. Then ground the X0 terminal and size it per my load that now is my equipment neutral. Obviously I’d supply additional egc and terminate all in transformer ground bar. Including base and structured steel.

See 250.30(A)(8) for grounded conductor sizing.

 

[LarryFine]

Pretty much what I figured. Back of my mind I’m thinking why not just give your wye load your incoming delta neutral. Just like to be sure ty

Nope.