Thanks all for the responses. It certainly confirms what I was already thinking and gives me additional food for thought. I was hoping there was a way to fix this system without adding a grounding bank. But it certainly seems like this is the best way to go. Thanks again!
That makes perfect sense, and quite similar to what I was thinking. Interesting about the buried delta. What do you look for on the nameplate that will show if you have one or not?
I am working on a system that is installed with an ungrounded-wye (480V) to grounded-wye (13.8kV) step-up transformer (T1). After the voltage is stepped-up the system goes through a series of switches, and eventually gets stepped back down via a grounded-wye (13.8kV) to grounded-wye (480/277V)...
