DEVICE FOR TESTING DISCONNECTION DETECTING FUNCTION IN FIRE ALARM EQUIPMENT

PURPOSE:To detect a fire signal in the case of testing a line disconnection detecting function depending on the receiver, etc., of a fire alarming facility and further to prevent a fire sensor from being destroyed even when the fire sensor is activated while testing the disconnection detecting function. CONSTITUTION:A reception resistor Rr is connected in series to a fire sensor SE, and the disconnection detecting function is provided on the fire alarming facility so as to discriminate whether a line is disconnected or not by comparing a reception signal detected by the reception resistor Rr with a reference voltage. A constant current circuit FET 11 to make a current flow with a value smaller than the operating current of the fire sensor SE is provided on the reception resistor Rr in parallel and a switching element SW1 is provided on the constant current circuit FET 11 in series.