The Fire Alarm Systems (FAS) play an important role in the safety of life, properties and, others.
The Fire Alarm Systems are installed in various locations like school, college, hospital, shopping mall, commercial building, public places, industry, railway station, airport, and others.
The Fire Alarm Systems is designed with help of different components like fire alarm control panel, primary and backup power supply, monitoring and detection unit (alarm initiating device), notification unit, remote control and display panels unit, and others.
The block diagram of Fire Alarm System is shown in the fig. 1.
Fire Alarm Control Panel (FACP):
The Fire Alarm Control Panel is the brain of a Fire Alarm System and it is called the control center of FAS.
The FACP is used to monitor and control the function of FAS. The FACP is interfaced with the detection unit, display panel unit, notification unit and remote control unit.
The detection device like smoke detectors, carbon monoxide detectors, flame detectors, heat detectors, manual call points, and others send information signal about the location condition to the FACP. Based on this information, the FACP enables notification devices like a horn, alarm, bell, speaker, and others. They inform the authorized person about the fire, unhealthy condition, and smoky condition by sending mail, fax, message and calling on mobile, and other methods. They also inform the peoples working in a particular area.
In FACP, the authorized person controls the Fire Alarm System manually as needed. With the help of audible and visible indicators, the FACP displays the status of the Fire Alarm System.
The Fire Alarm Control Panel has cabinet made with metal or other materials. In the power failure condition, the FACP has batteries operated back up system. With the help of the FACP cabinet, the user can easily see the status of FAS without opening the cabinet door.
Power Supply Unit (Primary and Secondary Power Supply):
In the fire alarm system, primary and secondary power supplies are used. The primary power supply is designed with 110 VAC, 60 Hz or 240 VAC, 50 Hz and it is used constantly. The secondary power supply is called back up the power supply and designed with 6V/9V/12V d.c. battery. The secondary power supply is used, when a power failure condition occurs. The maximum battery capacity for this type of supply is around 12 to 18 AH (Ampere Hour). The secondary power supply is connected to the 12V/24V Fire Alarm Control Panel.
Monitoring and Detection Unit (Alarm Initiating Devices):
In Fire Alarm System, the detection devices are used. The detection devices send information about the location condition (fire status, emergency condition status, and other) to the FACP.
In Fire Alarm System, manual and automatic type alarm initiating devices are used.
The smoke detectors, carbon monoxide detectors, flame detectors, heat detectors, water flow detectors, and multi-sensor detectors are automatic detection devices.
The manual call points are energized by persons by the broken glass or pull the glass. Due to that, they are called manual detection devices.
Alarm Notification Device
The alarm notification device is an important part of the fire alarm system.
The alarm notification device is triggered by the initiating device like detectors (detect fire or danger condition) and enable the sirens, horns, bells, speakers, Strobes, Chimes, and others.
Based on this alarm notification system, the peoples inside the working area and an authorized person get notification about the unhealthy condition.
The alarm notification devices are also triggered when maintenance and inspection issues are detected.
Remote Control and Display Panels
The operator sets the parameters of the fire alarm system remotely when the distance between operator and fire alarm control panel is far.
With the help of remote control and display panel, the authorized person easily check, enable, and disable fire alarm system throughout the working area from their location. So these components are very helpful for larger applications.
Building Safety Interfaces:
The building safety interfaces communicate with the building’s access control system.
In the event of an unhealthy condition or emergency condition, building safety interfaces magnetically hold doors in the open positions or keep doors in a closed position to restrict the passage of smoke from one location to another location.
In the event of an unhealthy condition or emergency condition, building safety interfaces like the sprinkler systems are started automatically.