Can a Open Delta PT be used to pick up a ground fault in a ungrounded delta-delta system?

[MrJLH]

Was looking at one of out electrical system
n were to occur, or at least I think there is not. (i.e. no zig-zag transformer)

There is open delta PT that are normally used to provide voltage inputs into a GE 850 feeder protection relay. If a ground fault were to occur, how would the voltage inputs from the open delta PT's be interpreted by the 850 relay?

Thanks

 

[jim dungar]

Using open-delta connections, for metering circuits, has been common on 3-wire systems for almost 100 years.
The only difference between an open and closed deltas is the amount of load current they can supply versus their size. Their output voltages would be identical as long as they are not overloaded.

You would need to read the manual to see which specific GF methodology is used by the relay.

 

[JoeStillman]

I think you need a 59G function. That kind of relay is connected to a broken delta with 3PT's, not an open delta. They talk about it in the Buff Book, section 4.4.10.



I don't see 59G on the 850 FPR web page.