The contactor and smps are overspecified in order to accommodate the initial surge current of the motor at start-up. The circuit breaker, however is incorrect. It should have a lower tripping current than the components it is designed to protect. It is normal practice to install a type-C circuit breaker in order to accommodate the motor initial surge, rather than choosing a breaker with a higher trip level. The motor-contactor should also have a thermal overload fitted. |