Why might a shunt trip breaker trip in a Motor Control Center with an ATS22 soft start?


28 July 2022

Shunt trip accessory to the main breaker is tripping

Product Line:
ATS22 Soft Start

Motor Control Centers using an ATS22 Soft Start with a shunt trip breaker

Time delay relay is set to the wrong time.

Increase the time on the time delay relay.  This relay is used to delay the energization of the shunt trip coil when the bucket is powered ON.  The shunt trip coil must not be allowed to energize until the normally closed trip relay on the soft start has time to open.  Also, if the ATS22 goes to a faulted state, the shunt trip will trip the breaker.