Basic Working Principle of Fire Alarm System
Fire Alarm system mainly complies with NFPA72 code. Now we’ll see the working of the Fire Alarm system in particular Building.
Let’s take an example of a familiar place we all visit, i.e. Mall.
If the fire initiated inside the Mall, the smoke detector senses the smoke and indicates Fire Alarm Control Panel (FACP),
Fire Alarm Control Panel(FACP) programmed as per the individual building requirements with local civil defence codes and standards. Currently, we will see an example of the Mall.
Here when the detector and indication sense smoke has occurred in FACP, the system specialist along with security is given three minutes to investigate whether it is the real fire or just dust that detector has sensed.
If it’s only dust, then system specialist along with security, acknowledges the FACP and silences the alarm Whereas no further fire signal will be initiated in Building.
If it is real fire then after 3 minutes, FACP automatically gives a signal to sounder/flasher and public address in building to give evacuation message and sound an emergency alarm in Building.
So people in Mall can evacuate the BuildingBuilding immediately, which is the first step FACP initiates, below we are going to see the sequence.
FACP sends the signal to Access Control system to unlock all Entrance Access doors and fire exit doors and other room where general public and staff are inside Mall.