A little while back, I was putting in a delta-wye transformer (480V in, 480/277V out) as an isolation transformer to lower the available fault current to an air compressor with a VFD. Someone suggested that it really should be a delta-delta transformer in that application, but since we had a delta-wye on hand, it would be fine.
Anyone know what the advantages would be for a delta-delta? I always thought that delta-wye was preferred for industrial applications because you would be able to ground the wye and limit the voltage to ground to 277V in this case. Would it deal with harmonics better since it is powering a VFD?