Corner Grounded Delta 480 volt

[fhouck]

1) Can a standard open transition type 3 phase transfer switch be used in a Corner Grounded Delta system to feed the same loads?

2) Can a generator of 3 phase 480 volt wye be used for the back up source for the same system?

 

[davidbeach]

1) It depends.

2) It depends.

Yes and/or No are just as valid answers. There would need to be a lot more information about the system to know for sure one way or another. Where, and what governing codes, would also make a difference.

 

[sjohns4]

Code compliance aside, I've seen new equipment installed in a facility with a corner grounded delta. We did an upgrade at a plant that had a corner grounded delta service. We didn't add a transfer switch however; but there were existing generators and transfer switches present that were much newer than the existing electrical service.

The VFD's and motors we had installed didn't seem to mind.

I recall the EE missed it, I didn't realize it (or even knew such an animal ever existed) until I was looking at the startup reports and saw the odd voltages between, I guess it was L-G...don't recall exactly. Fortunately for us, nothing we had installed was looking for 1-phase 277. There may have been some drive parameters that had to be set, but there again I don't recall specifically. I do recall there were several that weren't right at startup.

Mike