The "vacuum circuit breaker" is named after its high vacuum in both the arc extinguishing medium and the insulation medium in the contact gap after arc extinguishing; It has the advantages of small size, light weight, suitable for frequent operation, and arc extinguishing without maintenance, and is widely used in distribution networks. Vacuum Circuit Breakers are indoor distribution devices in three-phase AC systems, which can be used for the protection and control of electrical equipment in industrial and mining enterprises, power plants, and substations. They are particularly suitable for use in places that require oil-free, less maintenance, and frequent operation. Circuit breakers can be configured in central cabinets, double-layer cabinets, and fixed cabinets to control and protect high-voltage electrical equipment.