What Is Fire Alarm System: How It Works & Types

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What Is Fire Alarm System

Fire alarm system is made up of a number of devices working together to detect and warn people of fire. These alarms may be activated automatically from smoke detectors, heat detectors or through manual fire alarm activation devices such as manual call points or pull stations.

The fire alarm system components include: The control panel – the system hub monitors inputs and system integrity, controls outputs and relays information. Primary power supply; supplied in the form of 124V or 240V AC from the power company.

How Fire Alarm System Works

The fire alarm system can be set off automatically by smoke detectors, heat detectors or manually. These sensors are programmed to detect certain levels of heat or smoke that could be an indication of fire.

Once a fire is discovered by this system, it tells the occupants of a building about the fire by making lots of noise and flashing lights.

Aside from notifying and warning occupants of fire, automated fire alarm system can also:

Shut down the air handling fans and the smoke dampers in the air ducts to prevent the spread of smoke and flame.
Turn on a deluge sprinkler system to extinguish a fire
Activate a preaction sprinkler system to allow it to extinguish fire.
Unlock doors to allow exit
Lock doors to prevent entrance
Close smoke barriers or smoke curtains to prevent the spread of smoke or flame
Activate fire suppression systems, etc.

Types Of Fire Alarm Systems

There are basically two (2) types of fire alarm systems:

Heat detector: This device responds to a rise in temperature and gets activated in case of a fire. It triggers an alarm by either melting a low fusing alloy or bending a bimetallic strip. They are intended to minimize property damage by reacting to the change in temperature caused by a fire. They are mostly fixed in garages, kitchens, etc.
Smoke detector: A smoke detector is a device that senses smoke, typically as an indicator of fire. The smoke detector are of two (2) types – Optical smoke detector and ionize smoke detector. The optical smoke detector act like an electronic eye while the ionized smoke detector ac like an electronic nose. All smoke detectors consist of two basic parts – A sensor to sense the smoke and a very loud electronic horn to wake people up.

Read Also: How to use a fire blanket

Regardless of the type of detector or alarm selected, the proper placement and maintenance of the device is crucial. Follow all manufacturers instructions for placement, testing and maintenance. The NFPA suggests battery replacement at least once a year on battery equipped units and a monthly detector test to verify the alarm function.

NOTE: Alarm installation and maintenance must always be done by a competent person.