How to choose suitable contactor and circuit breaker for electric motor
Under the AC circuit of 380V, how to choose suitable current of circuit breaker and contactor. The current size = 2 times of the power (KW), that is, 1.736*ITV80% (power factor).
The current of the circuit breaker (fuse in the picture) + switch needs to be larger. It can be 1.3 times. Take 22KW motor for example, its working current is about 45A, the starting current is about 8 times, it can choose 63A molded case circuit breaker.
AC contactors and thermal relays are also selected in the same way.
Difference between MCB miniature circuit breaker and MCCB molded case circuit breaker
Classification of circuit breaker
Contactor types, structure and working principle
Circuit breaker structure and working principle
Ac Contactor working principle and structure