PURPOSE: To allow a supervisor to cope with a fault nearly till a person in charge of a monitor center visits the center by recognizing the fault and its kind to the building supervisor.

CONSTITUTION: A monitor panel of a supervisor's room is provided with a system fault input means 1, means 2,3 displaying a fault depending on the type of the fault and the location, a fault processing means 5, a buzzer alarming means 6, and a buzzer control means 7. Then a fault signal is detected to discriminate whether or not the system is faulty. A fault notice is given to the monitor center, the display of occurred fault is displayed on a designated LED and a buzzer is activated. Moreover, even when the system fault is caused or not caused and when a buzzer stop key is depressed, the buzzer sound is stopped and an LED not faulty goes off and the LED for faulty part is lighted and the usual installation fault is monitored.