ZW10-12 series outdoor high voltage vacuum breaker are three phase AC outdoor HV switching devices, the breaker is mainly used for distribution systems in country or city networks, mines, railway and ports with 12kv level, rated current 630A, rated frequency 50Hz, especially for outdoor overhead line. It switches on / off load current and overload or short current to switch and protect eletric networks. Matching with a disconnecting switch, the preaker can be a combined switch. The disconnecting switch is installed on the side of the breaker body, combining with the breaker by the angle iron underframe. On the transmission shaft, the interloking device is installed for matching with breaker's mechanism. So it can prevent from incorrect manipulation. Matching with a reclosing controller or segmentation controller, the breaker becomes a recloser(or sectionalizer )n intelligerce breaker. Matching with a reclosing controller and PT, the breaker has three segment compound protection of switch on rush current control, over current protection and short quick break. And it has 1-3 times of reclosing, low current ground protection, wired supervisory control functions. It can also remote control under the pole, and comtinuously regulate parameters of the breaker. It is an ideal choice for spot switch and simple measurement switch outside country network substations.