An existing 4000Amp service has a 4000A breaker that feeds another part of the building. As per original design it has ground fault protection.
The building electrical system was redone in 2012 and the 4000A service was re-fed via a new 2000A breaker in the new line up.
A large load was removed from the original service.
A shorted elevator motor fed from the original buss tripped out the 4000A breaker to the other part of the building. I would guess the close proximity of the fault to common buss may have caused the trip of the 4000A breaker.
Building engineer wants to disconnect the ground fault mechanism on the 4000A under the theory that this buss is now fed from a 2000A breaker ( new electronic SQ-D ) and the 4000A does not need to be ground faulted.
Looking at 215-10 and 230-95 not sure it would be legal todo this?
The building electrical system was redone in 2012 and the 4000A service was re-fed via a new 2000A breaker in the new line up.
A large load was removed from the original service.
A shorted elevator motor fed from the original buss tripped out the 4000A breaker to the other part of the building. I would guess the close proximity of the fault to common buss may have caused the trip of the 4000A breaker.
Building engineer wants to disconnect the ground fault mechanism on the 4000A under the theory that this buss is now fed from a 2000A breaker ( new electronic SQ-D ) and the 4000A does not need to be ground faulted.
Looking at 215-10 and 230-95 not sure it would be legal todo this?
