Phase loss protector for three-phase power source

The utility model relates to a phase loss protector for a three-phase power source, particularly an electric protector for low voltage apparatus, which can emit control signal to cut off a loaded power supply source when the three-phase power supply loses phases. A leading wire and a control connecting terminal of the three-phase power supply are arranged outside an insulating shell of the protector, and a three-phase rectifying circuit, a triggering control circuit and a miniature relay are arranged in the shell. The protector directly takes signals from the voltage of the loaded three-phase power supply, and fits with an AC contactor in a motor controller loop to play the function of phase loss protection on a motor.