The AB-3S-12 series circuit breakers are recently-developed pole-mounted intelligent vacuum circuit breakers of a new generation, which absorb the advanced domestic and foreign technologies adopted by our company, embody the design concept of being“ intelligent, energy-saving, environmentally-friendly and maintenance-free”and comply with the actual conditions of China’s power distribution network and the construction requirements of smart grid. These products can be used as switches at the 10kV side of substation and 10kV outgoing line of main transformer as well as pole-mounted switches for power distribution networks. They integrate such functions as measurement, control, protection, communication, fault isolation and network reconfiguration, with high automatic and intelligent degrees; they are top choices for equipment of power distribution network automation and miniaturized substations.