YKQ2 series of intelligent double power automatic change-over switch is used on the double power supply system of AC 50/60Hz, rated voltage 690V and below, rated current 1250A and below. The products realize the change-over of the common power (N) and standby power (N). The products is used for special, 1 kind power system, high rise building, residential, military facilities, hospital, airport, wharf, shopping mall, communication, fire fighting, metallurgy, chemical industry, textile, petroleum, mining places.