Vacuum contactor is a device that can withstand multiple operations (strong mechanical life). It can cut off the load current at the same time, but can not break the short-circuit current. The vacuum contactor has two contacts, normally open and normally closed, and does not have the function of short-circuit current protection. When a given signal is received, it can perform separation and hold actions. Analogus to ordinary home circuit, VCB is like a circuit breaker at home inside a panel and VC is a relay in our any of instruments at home.