sanchezjl
Electrical
- Nov 28, 2004
- 7
Hi..
I have a question for the relay engineers..
Recently we had a trip in one of our substations transformers where we are using a SEL-387 relay with an external single phase to ground fault.
One the event was downloaded; we sent it to SEL because it was not clear for us (operations put the transformer in service without diff protection and it worked, but today we took it out of service for inspections).
The thing is that they realize that the hi side C phase and the low side C phase (the faulted phase) where in phase and around the same magnitude before the fault, but during the fault it was a 50 degrees shift between those two.
Have any of you guys had something similar in the past?
I will appreciate your answers.
Thanks!
I have a question for the relay engineers..
Recently we had a trip in one of our substations transformers where we are using a SEL-387 relay with an external single phase to ground fault.
One the event was downloaded; we sent it to SEL because it was not clear for us (operations put the transformer in service without diff protection and it worked, but today we took it out of service for inspections).
The thing is that they realize that the hi side C phase and the low side C phase (the faulted phase) where in phase and around the same magnitude before the fault, but during the fault it was a 50 degrees shift between those two.
Have any of you guys had something similar in the past?
I will appreciate your answers.
Thanks!