Disclosed is a control and protection device for a low-voltage electrical apparatus, comprising a pedestal and a control and protection module. The control and protection module may be plugged into the pedestal and is replaceable. The pedestal comprises a base and a housing, and is further provided with a moving contact, a static contact, and a current conductor connected to a main circuit current; a control electromagnet operation mechanism for controlling close and open of the moving contact and the static contact according to a control signal, and maintaining a close or open status of the moving contact and the static contact; a manual operation knob providing a control signal for controlling the close and open of the moving contact and the static contact; a control contact connected to the manual operation knob; and a current sensor for detecting a current that flows through the main circuit current conductor and generating a sensing signal. The control and protection device further comprises: a signal processing unit for controlling a state of the control electromagnet according to the sensing signal via an electrical circuit; and a tripping device for controlling actions of the operation mechanism with a mechanical connection in response to the signal processing unit. The current sensor has a secondary circuit connection detection device.