Fire Alarm Signal Circuit

A circuit where automatic or manual initiating devices are connected and the signal does not identify the individual device operated.

Fire alarm signal circuit.

For some more advanced systems the panel may indicate the kind of problem and where it is located. The total current draw for all the devices connected to the circuit cannot exceed the nac rating. Audible appliances have been in use longer than any other method of notification. A fire alarm notification appliance is an active fire protection component of a fire alarm system.

There are three basic categories for fire alarm panel signals. A condition which may be caused by an interruption of the data communication link or signalling line circuit caused by either an open circuit short circuit or device failure. The signaling line circuit is used by the main computer fire alarm control panel or facp to communicate with all the sub computers detectors and modules. The data sent from the facp to the detectors and modules carries information like address and polling and sometimes programming.

Initially all appliances were either electromechanical horns or electric bells which would later be replaced by electronic sounders. 9 6 fire detection alarm and communications systems. This information can be found in the manuals provided with the panels. Most of today s appliances produce s.

If an open additional troubles may also be queued that relate to the failure of one or more active field devices from communicating their condition with the common control. Trouble supervisory and alarm. Signal circuit nac on a fire alarm panel. Fire alarm circuit classes 2007 nfpa 72 6 4 2 1 class.

9 6 fire detection alarm and communications systems. Trouble signal a trouble signal is typically designated by a yellow light and means that there is an operational issue. A notification appliance may use audible visible or other stimuli to alert the occupants of a fire or other emergency condition requiring action. In the wireless fire alarm system a radio signal is transmitted from the detector such as heat detector or call point to the central fire alarm system to activate the alarm circuit.

Initiating device circuits notification appliance circuits and signaling line circuits shall be permitted to be designated as either class a or class b depending on their performance during nonsimultaneous single circuit fault conditions as specified by the following. Alarm supervisory trouble opens and grounds on a fire alarm circuit will result in a blank signal. Each nac notification appliance circuit in a fire alarm panel or booster power supply has a maximum current rating.