KYN28A-12series metal close switchgear (centrally installed swithgear) is suitable for the three-phase ac 50Hz power system. Mainly used in power plant, small and medium-sized generator power, industrial and mining enterprises, power distribution as well as the electric power system secondary substation by electricity, transmission and large high voltage motor starting, etc., to achieve control protection, monitoring purposes. The switchgear meet GB11022, GB3906 standard requirement, prevent the loading of push-pull circuit breaker handcart, prevent or circuit breaker, to prevent the earthing switch is in the closed position close circuit breaker, avoid straying into charged across the room, avoid mistake when charged and earthing switch interlock function, as well as with my company developed ZN63□/12 type vacuum circuit breaker, but also with the ABB VD4, American GE VB2 vacuum circuit breaker, it is a superior performance of the power distribution device.