Fire Detection System

A fire alarm system has a number of devices working together to detect and warn people through visual and audio appliances when smoke, fire, carbon monoxide or other emergencies are present.

These alarms may be activated automatically from smoke detectors and heat detectors or may also be activated via manual fire alarm activation devices such as manual call points or pull stations.

Alarms can be either motorized bells or wall mountable sounders or horns. They can also be speaker strobes which sound an alarm, followed by a voice evacuation message which warns people inside the building not to use the elevators.

Basic Components of Fire Alarm Control System

Fire Alarm Control Panel

Input Devices

Out Devices

FIRE ALARM CONTROL PANEL

The brains of the system

Provides power to the system, monitors inputs and controls outputs through various circuits.

Performs other functions as required by the appropriate code.

Addressable Fire Alarm System

Every device connected to the addressable system has its own unique address. When a fire is detected, the device’s address shows up on the main control panel, telling us exactly which device has been activated. This will enable us to find the exact location of a fire and extinguish it quickly.

1. Each device (detector, pull station…) has a unique number assigned to it called the address for reporting alarms and troubles.

2. Employs a Signaling Line Circuit (SLC) Loop along which all addressable input and output devices are connected to the fire alarm control panel.

3. Addressable devices transmit an electronic message back to the Control Unit representing their state (Normal, Alarm, Trouble) when polled by the Control Unit.

Conventional Fire Alarm System

With a conventional system, there is no way of pinpointing the exact location of the fire. By wiring your building into different zones, one can get a general idea of where the fire is. For instance, if you have two floors, you could wire the first as ‘zone and the second as zone 2. So, if a fire occurs in zone 1, you know that the fire is somewhere on the first floor.

1) The simplest type of control unit. Generally, a single circuit board contains a power supply, control, initiating and notification circuitry.

2) Some models use auxiliary circuit boards to perform special functions.

3) Input/output devices connect to dedicated circuits.

4) Designated outputs occur when initiating signals are received.

Limited special functions and capabilities.

INPUT DEVICE

A fire alarm system can have a variety of input devices. We divide it into two parts, one is Initiating Device and one is Initiating Device Circuit (IDC). A system component that originates transmission of a change of state condition, such as a smoke detector, manual fire alarm box, supervisory switch, etc is known as Initiating Device. A circuit to which automatic or manual initiating devices are connected where the signal received does not identify the individual device operated is known as a Initiating Device Circuit (IDC)

Multi-Sensor Detectors

The Multi-sensor detectors combine inputs from both optical and heat sensors and process them using a sophisticated algorithm built into the detector circuitry. When pulled by the control panel the detector returns a value based on the combined responses from both the optical and heat sensors. They are designed to be sensitive to a wide range of fires.

Smoke Detector

A detector or a sensor that senses smoke and act as an indicator of fire. It basically issues an audible or a visual signal to the fire alarm control panel in case of fire.

Beam Detector

System Sensor is offering a new single-unit Transmitter/Receiver Beam Detector that works in conjunction with a reflector.

Duct Detectors

Photoelectric detector mounted in housing outside the ductwork that has probes that extend into the duct to air inside the duct. Primarily used as a smoke control device to control the flow of air in ductwork.

Heat Detectors

Heat detectors are the oldest type of automatic fire detection device. Not considered direct Life Safety devices, these detectors do contribute to the detection of a fire.

Monitor modules

They supervise a circuit of dry-contact input devices, such as conventional heat detectors and pull stations, or monitor and power a circuit of two-wire smoke detectors.

Optical beam smoke detector

A device that uses a projected beam of light to detect smoke across large areas, typically as an indicator of fire. They are used to detect fires in buildings where standard point smoke detectors would either be uneconomical or restricted for use.

Manual Call Point

Manual alarm call points are designed for the purpose of raising an alan manually once verification of Manual Call Point: Manual alarm call points are designed for the purpose of raising an alarm manually once verification of lire or emergency condition exists by operating the push button or break glass to raise an alarm signal.

OUTPUT DEVICE

Fire Alarm Hooter

The Fire Alarm Hooter is a device which produces sound when a sensor senses any kind of fire activity.

Control Module

They is the output side. It activates warning devices like a bell or horn strobe. It can also activate relays connected to automatic door closers. elevator controls, fire suppression systems, smoke ejectors, and the like.

Bells

Only used if they are only for fire, or have a distinctive sound from other bell signalling devices. Often used as an external gong to indicate the flow of water in the sprinkler system.

Horns

Loud and distinctive output. Often used in high-noise environments. such as manufacturing plants

Horns Strain

Visual signalling appliances are used in high-noise environments, in areas occupied by hearing-impaired individuals, or in areas where audible devices may not be desired.

Fire Detection System