Equalizing Ground Fault


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How can we equalize the ground fault in ground fault current with open delta voltage?

A generator is protected by a ground fault CT of 200/5 set to 2.5A secondary. When synchronized with grid the NGR switched off and the only protection of ground fault depends on open delta PT 11KV/110V. Somebody can guide how much secondary voltage of open delta would be equal to 2.5A secondary fault current of CT?

Shaheed... PTs having their secondaries open-delta (connected) usually have their primary-windings connected phase-to-phase.

Thus, they will not respond to earth-faults!

Regards, Phil Corso