ZW8-12 series ourdoor HV vacuum automatic circuit reclosers (short for break) be used for switching on/off load current, overload current and short circuit current in three-phase power systems with AC 50HZ and rated boltage 12KV. Matching with recloser controller, the breaker can identify current characteristics and realize repetitious autoeclosing or permanent fault isolation. With its own PT power, it becomes an intellience breaker having controlled voltage and current signal output. With electronic PT power, it provides three segment compound protection of over current time delay, rush current time delay and short circuit quick break.