It is suitable for AC 50/60HZ application with a rated voltage up to 690V under the AC-3 use category and with a setting current range 0.1A~32A; it can replace the combination of 3-pole circuit breaker and thermal overload relay functionally to realize the motor protection in case of short circuit, thermal overload, and phase loss，It can also be used for infrequent line conversion or direct start of the motor.