VS1-12 type indoor high voltage vacuum circuit breaker is the indoor switch device for three-phase AC 50Hz, rated voltage 12kA power system, can be used for electrical equipment control and protection in power plant, substation and industrial and mining enterprises, and is suitable for frequent operation place, can be installed in the KYN28-12 type and other armored cabinet, can also be installed on the fixed cabinet or gas insulated cabinet. Design feature VS1-12kV indoor medium voltage sealed vacuum circuit breaker (12kV, .4000A, .50kA) VS1 indoor medium voltage sealed vacuum circuit breaker with maintenance free sealed vacuum pole, can equipped with modular spring assembling actuator and permanent magnetic actuator; has the features of reliable performance, long mechanical life, maintenance free, small mechanical movement, has the advantages of simple structure, good process performance, but also can be applied to all kinds of bad working environment. VS1 circuit breaker pole adapts the solid insulation sealing technology, seal the vacuum interrupter and primary main galvanic circle and other parts into strong insulation, high mechanical strength pole with epoxy resin, avoid the influence of adverse operating environment on the primary circuit external insulation, realizes completely maintenance free. VS1 circuit breaker adapt ultra low resistance type vacuum interrupter, meet the VCP circuit breaker requirements on the temperature rise at big current operation situation and reduces the power losses. VS1 circuit breaker adapt optimization and modular spring operating mechanism, simple structure, stable performance, convenient maintenance; modular production process is good, easy standardization production, short delivery cycle.