ZW7-40.5 outdoor high-voltage vacuum circuit breaker (hereinafter referred to as circuit breaker) is a three-phase AC 50Hz outdoor high-voltage switchgear suitable for rated voltage of 40.5kV. The circuit breaker complies with the national standard GB1984 "High Voltage AC Circuit Breaker" and the professional standard JB3855 "3.6~40.5kV Outdoor AC High Voltage Vacuum Circuit Breaker" and related IEC standards. It can be used for control and protection of electrical equipment in industrial and mining enterprises, power plants and substations, and is suitable for places with frequent operations. The circuit breaker has the ability of multiple opening and closing and fast re-closing.