We recently had an incident at our company in which a Grounded Low Voltage motor (30kW, 480VAC, 60Hz) led to the tripping of entire MCC bus. The motor is fed through a Square D Model 6 MCC. Our System is solidly grounded and the maximum available GF current at the Motor terminals is around 20kA...
have recently come across a nuisance tripping issue that has me baffled. We have a 34.5kV switchgear feeding two Motors (call them A and D). Both motors are protected by GE 469 MMR and are exactly identical. Recently both motors tripped on Ground fault at the same time. I was called to the plant...
