The ZW7-40.5 series outdoor vacuum automatic circuit breakers are outdoor HV electrical equipments on three-phase AC 50 HZ. It is used for controlling and protecting 24~40.5KV transmission and distribution system.It can also be used for network interconnecting breaker and switching capacitor bank matching with segmentation and reclose control of power systems. Annexing a current transformer inside, it provides measurement and protection. Matching with spring or electromagnetism operating mechanisms, the breaker has highe reliability of mechanical property and can be operated frequently. It has no burning and exposion hazard. The breaker conforms to standard of GB1984-1989AC HV Breaker and IEC56,IEC62271-100 HV AC Breaker.