ZW32-12 Our-door high voltage vacuum circuit breaker (hereinafter called Breaker) is an outdoor distribution device of rated voltage 12KV, AC three phase of 50Hz, which is mainly used to switch on/off the loading, overloading and short circuit current in the electric system. It is applied to the control and protection of the distribution system in enterprises and substations. It is also used at the place where the operation is frequently done in the rural electric power net. It is in accordance with the national standard of GB1984-1989 "AC HIGH VOLTAGE BRESKER" and the international standard of IEC56.