600V solid ground fault protection
600V solid ground fault protection
(OP)
I am doing a protective coordination for 600V system, which is the secondary side[Y] of 1500KVA Transformer. The sencondary side is 3W+[N+G]. N& G are in one wire. GF current calculated is 7.6KA, 3phase fault current is 10.1KA.
I am wondering if we need any G-F protection on MCC main breakers. If so, how can I do the settings?
I read IEEE Buff book. It mentions that G-F setting on the mains should be higher than the phase fault protection settings on the branches.Time delay should be longer than 0.1s. Is is right? But the problem is, it is hard to achieve such high G-F settings on some breakers. Who have a better solution for this?
Thank you in advance.
I am wondering if we need any G-F protection on MCC main breakers. If so, how can I do the settings?
I read IEEE Buff book. It mentions that G-F setting on the mains should be higher than the phase fault protection settings on the branches.Time delay should be longer than 0.1s. Is is right? But the problem is, it is hard to achieve such high G-F settings on some breakers. Who have a better solution for this?
Thank you in advance.






RE: 600V solid ground fault protection
If the transformer feeds one main, that main has motor breakers as the next layer, and you put ground fault trip on all of the motor breakers you need not have any coordination issues.
RE: 600V solid ground fault protection