VS1+ indoor high voltage vacuum circuit breakers (hereinafter briefly refers to as breaker) is an indoor unit of 3-phase AC 50Hz and with a rated voltage 0f 24kV. It is suitable for switching various loads of different properties and can be used as power equipment for industrial and mining enterprises and protection & control unit for the electric equipment of power plant and substations. Because of the special performances of the vacuum breaker, it is especially suitable to the applications requiring frequent operation. The breaker of this model is optimized and designed on the basis of model VS1 and new SS1 Mechanism is equipped. The actuator is very succinct and the latest maintenance free technology is adopted. It possesses very high operation reliability, the mechanical service life can be 30000 times and the rated short circuit drop-out current is as high as 50 times. The installation mode of the breaker in the switching cabinet can be the fixed mode or specific push-in mechanism is equipped, a hand-cart unit (drawing out type) for operation