A circuit breaking system includes an output device for outputting an output signal; a control device controlled by the output signal; a power input terminal provided in the output device, for supplying power to the control device; a power supply to the output device, which has a ground terminal; a break circuit disposed between a power output terminal and the power input terminal; a switching circuit disposed between the break circuit and the power output terminal; and a short circuit disposed between a ground and a node which connects the power input terminal and the break circuit. The break circuit and the short circuit are operated so as to not be closed at the same time. When the switching circuit is closed, the break circuit is closed while the short circuit is open. When the switching circuit is open, the break circuit is open while the short circuit is closed.