ZW32Y-12/630-20/25 type outdoor permanent magnetic H.V. vacuum on pillar dry circuit breaker (hereinafter referred to as circuit breaker), is the control and protection equipment used in rated voltage 12KV, 50HZ AC three phase high voltage distribution grid. Mainly used for load current, overload current and short-circuit current breaking, closing in the power lines. Applied to substation and industrial and mining enterprises in power system used for protection and control purposes. In accordance with "GB1984 AC high voltage circuit breaker", "GB1985 high voltage AC disconnectors and earthing switches", DL/T402, DL/T403 requirements.