What is a fire alarm system?
A fire alarm system consists of manual and automatic initiating devices that link to an alarm control panel which activates audible or visual alarms to give a warning to occupants to enable them to vacate a building or premises safely in the event of a fire.
How does a fire alarm system work?
Manual devices, are call points that when operated provide a signal to input circuits to the alarm control panel.
Automatic devices are either smoke, heat, beam or aspirating detectors, that activate when respective aspects particular to them are present which then provide a signal back to input circuits of the alarm control panel.
Upon receipt of an input signal from either manual or automatic devices, audible or visual alarms from output circuits on the alarm control panel are activated.
The alarm control panel also has on board auxiliary outputs or contacts to operate third party independent equipment for shutdown purposes.
The alarm control panel monitors the field wiring or cabling of the input and output circuits for open or closed circuit faults or any leakage to earth.
The alarm control panel maintains the fire alarm system under a mains supply failure for a minimum period of 24 hours and will still operate the audible / visual alarms for at least 30 minutes thereafter from standby rechargeable batteries either on board or within a separate external enclosure.
Applicable Standards & Legislation
- Regulatory Reform (Fire Safety) Order: 2005
- BS EN 54: fire detection & alarm systems.
- BS5839 part 1:2013 Fire detection and alarms for non-domestic buildings.
- BS5839 part 6:2013 Fire detection and alarms for domestic buildings.
- BS7671: 2008 (+A3: 2015) Requirements for electrical installation.
