Product Mechanism and Operating Principle of ZW32-12 Vacuum Circuit Breaker

ZW32-12 outdoor medium voltage vacuum circuit breaker(hereinafter referred to as circuit breaker) is an outdoor AC power distribution equipment with rated voltages of 12kV and service frequencies of 50Hz/60Hz. This equipment is mainly used to open/close load current, overload current and short circuit current. It can also be used as a control and protection electrical device in substations and the power distribution systems of mining enterprises, it especially suitable for city electric network and the reformation of rural electric network.

Product Mechanism and Operating Principle

1.Charging Operation

Operate the manual charging operating lever of ZW32-12 vacuum circuit breaker or send motor charging signal to the mechanism, so to make the cam rotates by the transmission gear, then the closing spring will be gradually stretched. After the spring across its middle, the cam stops rotate, the switch will be in the closing status; at the meantime, the cam detached from the rotation axis, so to make the mechanism cannot charge again.

2.Closing Operation

Operate the manual charging ring-pull of ZW32-12 vacuum circuit breaker or apply the voltage to the closing coil, to make the closing half shaft rotates, then the connecting lever release from the closing half shaft, the closing spring power releases, the output shaft of the mechanism starts to rotate. Which through the connecting lever, drives the moving contact of the vacuum interrupter to meet the fixed contact. It also supplies the contact pressure, to charge the opening spring at the mean time. Through the mechanism closing operation keep the circuit breaker in the closing status.

When the mechanism of ZW32-12 vacuum circuit breaker is in the closing status, then charge the circuit breaker, at this time, the closing spring is stretched again. After the spring across its middle, the closing axis shaft will be fastened by the interlock function to prevent the fault closing.

When the closing is in the charged states, the mechanism of ZW32-12 vacuum circuit breaker will be in the reclosing status, so to realize the “Open – 0.3s – Close” primary reclosing operation.

3.Opening Operation

After the ZW32-12 vacuum circuit breaker opened, operate the manual charging operating lever on the operating mechanism or apply the voltage to the closing coil, then the closing of the mechanism remaining in the detached status. With the operation of both the contact compressed spring and the opening spring, the mechanism output shaft rotates to its reverse direction. Which through the connecting lever, drives the moving contact of the vacuum interrupter to meet the fixed contact. Then the moving and fixed contacts will be separated, the circuit breaker open. The opening status maintains by the switch open spring.

4.Overcurrent Protection Procedure

The ZW32-12 vacuum circuit breaker equips with the current transformer, when the current through the main circuit exceeds the rated value of the current transformer, the output 5A current of the CT drives the overcurrent tripper in the internal mechanism, to make the circuit breaker open.