AC Vacuum contactor is type of Contactors in which Vacuum acts as Di-Electric, and help the contacts not to arc or spark while the contact makes or break the connection while on load conditions. They are used to isolate the load from the source in any abnormal condition like if there is short circuit at load end or there is over Current drawn by the load the Circuit breaker will break the connection of load and source by sensing from built in relay or external relay which is monitoring abnormal condition