PURPOSE: To prevent the overcurrent of house wiring and to lessen the operation of a breaker.

CONSTITUTION: When a plurality of appliances of large rated current values, a television set 3, a microwave oven 4, an air conditioner 5, etc., for example, are operated at the same time, a breaker 2 is operated by overcurrent. For preventing this kind of fault, a current detecting device 6 composed of a current detecting circuit 7 for detecting the current of house wiring, a microcomputer 8 for converting input signal voltage from this current detecting circuit 7 into a specified output signal, and a transmitting circuit 9 for transmitting the output signal of this microcomputer 8 to the air conditioner 5 is fitted to the house wiring. 10 is a current sensor for detecting the current of the house wiring. The microcomputer 8 begins to operate when the output voltage of the current detecting circuit 7 reaches a specified value or higher, and outputs a specified signal to a transmitting circuit 9 when the input signal voltage of an A/D port reaches a specified value or higher. The transmitting circuit 9 converts the input signal into an infrared signal for example, and transmits it to the air conditioner 5. When the control element of the air coditioner 5 receives the signal from the transmitting circuit 9, it lowers the numbers of rotation of a compressor, etc., and suppresses the input current.