gobblerhuntr
Electrical
- Mar 16, 2005
- 39
In setting a breaker relay (ABB DPU 2000r) for the 51p element our relay is set for a ickup of 5 with a 600:5 ct ratio, this means at 600 amps the relay will pickup and operate. The time dial is 1. On the 51p-1 element the pickup is set at 7.3, what is the calculation for this element's pickup, is it the 7.3 times the ct ratio or is there another factor involved?
Our 51N element is 1.2 and time dial of 6. I assume that this will start picking up at 1.2 times ct ratio, with a tardiness of 6 based on the time dial. Is this correct?
Then the 51N-1 element has a pickup of 20, so does this calculation go 20 times the ct ratio also?
Our 51N element is 1.2 and time dial of 6. I assume that this will start picking up at 1.2 times ct ratio, with a tardiness of 6 based on the time dial. Is this correct?
Then the 51N-1 element has a pickup of 20, so does this calculation go 20 times the ct ratio also?