Delta-Delta to a Delta-Wye

[bulltrout33]

We have a client who has a 2000kVA, 25kV to 480V transformer that has been damaged. We have found a similar replacement, but it is a Delta-Wye. Are we able to use this as a replacement, provided we ground the XO, or are we better off to have the existing one repaired? Any suggestions?

 

[iceworm]

We have a client who has a 2000kVA, 25kV to 480V transformer that has been damaged. We have found a similar replacement, but it is a Delta-Wye. Are we able to use this as a replacement, provided we ground the XO, or are we better off to have the existing one repaired? Any suggestions?

You don't give any information as to the existing system, other than it was fed with a D secondary xfm. We don't know if the existing system is corner-grounded, zig-zag, un-grounded, something else - one of a kind known only in your corner of Alberta.

So:
Probably - DON'T ground the X0. The wye secondary will look like a Delta secondary to the load.

As for repairing the existing - that is just a cost - leadtime issue. Get prices, leadtimes, see what is satisfactory to the customer

One thing: What damaged the existing? How do you know the same thing won't happen to this one? 2MVA is non-trivial. You might consider a specialist to do some fault analysis.

ice