ZW8-12 model outdoor AC vacuum circuit breaker is used to make and break load current, overload current and short-circuit current in a 12kV,50/60Hz power system. It’s applicable for substations, industry and mining, and urban and rural electric power networks, especially applicable in occasions with frequent operation and automatic power distribution networks. It accords with the standards of IEC62271-100 & GB1984: AC high voltage circuit breaker, IEC60694 & GB/T11022: HV General technical requirement of switch and control apparatus.