The ZW7-40.5 type outdoor high-voltage vacuum circuit breaker (hereinafter referred to as the circuit breaker) is a three-phase AC 50Hz device, suitable for outdoor high-voltage switchgear with a rated voltage of 40.5kV. The circuit breaker complies with the national standard GB1984 "High-voltage AC Circuit Breakers," the professional standard JB3855 "3.6–40.5kV Outdoor AC High-voltage Vacuum Circuit Breakers," and relevant IEC standards. It can be used in industrial and mining enterprises, power plants, and substations for the control and protection of electrical equipment, and is suitable for locations requiring frequent operation. The circuit breaker has the capability for multiple interruptions and rapid reclosing.