The current setup uses power from the CT's to charge a trip capacitor to trip the breaker.
Our spec. requires a pickup between 3 & 10 amps for a ground fault. Where we were even getting ground overcurrent protection I believe it was like 50 amp pickup which is greater than the rated current...
Ok that makes sense there is a minimum number of amps required for any CT to power a relay. In this case then I guess our vendor is saying that 3 amps is below that minimum value.
This may be a dumb question, but isn't it possible to power the relay using a CT or PT on one of the phase lines?
First, thanks for all the input.
Basically it was realized that the relay protection did not fully meet our desired pickup amp specification. We need a self-powered (or dual-powered) unit for safety reasons relating to our setup.
I understand the data collection advantages or maybe even a...
What are the limitations of self-powered relays?
We are pushing a vendor of our 34.5kV switchgears to provide 3A pick-up on ground faults with a self-powered relay. The vendor says that he doesn't believe one exists. If that is true, what is the reason?
I'm new to the company and I'm not...
I recently worked on a job with a 4kV circuit that had two A-phase loops. Most often these loops have an open point at one end or the other and I understand the benefit being the flexibility in that the load can be fed from either end. In this particular case, however, each of the loops were...
