It is suitable for indoor switchgear with a rated voltage of 12kV and a three-phase AC frequency of 50Hz, used as a control and protection unit for high-voltage electrical equipment. The vacuum circuit breaker adopts a modular spring operating mechanism, which is simple, mature, and reliable, ensuring the breaker’s performance is highly dependable. It can perform frequent operations or multiple short-circuit current interruptions within the working current range. The optimized modular spring operating mechanism is compatible with switchgear such as the KYN28-12 and XGN series.