GEESYS Technologies (India) Private Limited — Fire Alarm System
Fire Alarm System (FAS)
An automatic fire alarm system is designed to detect the unwanted presence of fire by monitoring environmental changes associated with combustion. In
general, a fire alarm system is either classified as automatic, manually activated, or both. Automatic fire alarm systems can be used to notify people to
evacuate in the event of a fire or other emergency, to summon emergency forces aid, and to prepare the structure and associated systems to control the spread
of fire and smoke
Before we tackle how a fire alarm system works, let us first review what a fire alarm system is. A fire alarm system is an active fire protection system that
controls all the fire alarm modules in a building. The phrase active fire protection refers to items or systems that can be activated mechanically or electronically.
Fire alarm systems are composed of alarm initiating devices (smoke detectors and heat sensors), alarm notification appliances (sirens or devices that produce loud noises),
fire control units (sprinkler systems or fire extinguisher systems), power supplies and wirings.
Fire alarm systems notify the occupants of a building or a house of a possible fire so that the occupants can either evacuate for safety or extinguish the fire before it could
spread out and become uncontrollable.
The fire alarm system can be set off automatically by smoke detectors, heat detectors or manually.
These sensors are set to detect certain levels of heat or smoke that could be an indication of fire. A loud bell or a siren, sometimes accompanied by blinking or flashing lights for individuals who have hearing problems, blasts
to alert occupants in the building. To truly understand how a fire alarm system works, let us go further into the components of the fire alarm system.
In a fire alarm system there is always a smoke detector to detect smoke or fire.
Another aspect of how a fire alarm system works is the heat sensor or also called thermal sensor. A fire alarm system works by way of heat sensor in quite
simple way. The heat sensor monitors the temperature in a room and any abrupt rise or sudden extreme change in temperature triggers the fire alarm.
How does a fire alarm system work by way of smoke sensor? There are two types of smoke detectors.
These are the optical detector and the ionization detector. The optical smoke detector detects smoke by using light sensors (infrared LED). When smoke particles pass through
the chamber of the optical detector, it scatters light that triggers the alarm. In the ionization detector, if the smoke particle enters the chamber of the ionization detector
it will reduce air ionization inside the chamber of the ionization detector and triggers the alarm.
1. Conventional Fire Alarm Systems
Fire Alarm Systems fall broadly in to two groups - Conventional Systems or Analogue Addressable Systems.
'Conventional' Fire Alarm Systems, in their various forms, have been around for many years and have changed little in that time in terms of technology although design and
reliability have improved significantly. However, Conventional Systems are a well-proven technology protecting many hundreds of thousands of properties worldwide. A Conventional
Fire Alarm System is often the natural choice for smaller systems or where budget constraints exist.
In a typical Conventional Fire Alarm System the 'intelligence' of the system resides solely within the Fire Alarm Control Panel which receives a trigger signal from a Conventional Detector
or Call Point and in turn, signals the condition to other devices such as alarm sounders and remote signalling equipment.
Conventional detectors are normally connected to the Fire Control Panel via dedicated circuits, each circuit protecting a designated 'Zone' or 'Area' of the building (the maximum size of which
will often be governed by local standards). Detectors have two states, Normal healthy and Alarm.
2. Addressable Fire Alarm System:
Addressable fire alarm systems offer benefits in speed of detection, identification of the location of a fire and easier maintenance. Addressable fire alarm systems also offer tolerance to faults in the
system wiring, which allows a single pair of wires to be used to connect up to 200 devices to the system, allowing cost savings in the wiring of large systems. In larger installations, the benefits of improved
maintenance and reduced cabling cost are overwhelming. The price difference between Addressable systems and conventional systems has narrowed to such an extent that even for small installations, the use of an Addressable fire alarm system should be considered.
Main Functional Features of Fire Alarm System:
Detecting a fire at an early stage
Alerting and evacuating occupants
Notifying the relevant personnel
activating auxiliary functions e.g. smoke controls, lift homing etc
identifying and guiding fire fighters
Blocking Diodes for reverse current flow protection
Easy and decent Cable management
Time effective as well as money effective for cabling
Step by step trouble shooting methodology
Contemporary DC combining and disconnecting
Space saving and orientation flexibility
Load-break rated disconnecting
Traditional DC combining
Reliable electric safety to avoid hazard
Online Monitoring* (Optional for DCDB/ACDB)
GEESYS Fire Alarm System
TYPE OF SYSTEM
Fire Detection & Alarm System
NO. OF ZONES PROVIDED
1 to 200 zones
TYPE OF DETECTORS USED IN THE INSTALLATION
Ionisation type smoke detectors
Photoelectric smoke detectors
Fixed temperature cum rate of raise in temperature detectors
FAULT INDICATION/ALARM PROVIDED FOR
Open circuit in detector cabling for each zone.
Short circuit in detector cabling for each zone.
Battery low. (adjustable from 22 V to 23 V)
Two flashing red LEDs in the zone under "Fire".
Two steady glowing yellow LEDs in the corresponding zone.
One separate yellow LED for "Charger On" indication.
One separate green LED for "System On" indication.
AC & DC FUSE BLOWN INDICATOR
Separate red color LED for AC & DC "Fuse Blown" indication.
Fire: A beep sound in the panel. Fault: A continuous tone in the panel
After alarm cancellation Hooter sound changes to a low continuous tone & when another zone enunciates fire again, the main Hooter gets activated. Audio alarm can be silenced by ALARM CANCEL button.
Computer suites, EDP facilities and telecommunications hardware
Control rooms such as railway signalling centres and air traffic management centres
Stores and archives
Heritage sites such as art galleries and museums
Medical and laboratory equipment
Petrochemical plant, offshore oil and gas installations, pipeline pumping stations
Ship machinery spaces, rail locomotives and rolling stock
GEESYS Technologies (India) Private Limited — Expert in General Electrical and Electronics System