Fire Alarm Types, Categories and Grades
It is a legal requirement to have a fire alarm within your business premises that is in full working order. The choice of fire alarm system depends on the building structure, the purpose and use of the building and current legislation. The legal requirement is outlined by The Regulatory Reform (Fire Safety) Order 2005 and this ensures that almost all buildings excluding private residential homes have the correct system in place.
Owning a business premises means that it is your responsibility to ensure the building complies with the required standards of fire safety. The responsible person as defined by the RR(FS)O has to conduct a fire risk assessment. This assessment will decide the appropriate British standard necessary to provide a suitable and sufficient solution.
The current main standard for fire alarm systems is BS5839 pt1:2017
The 3 Main types of fire alarm systems
- Conventional Fire Alarm:
Suitable for smaller spaces and lower risk properties, conventional fire alarms divide a premises into zones, while all zones are continuously monitored if a fire was to occur the alarm panel will be able to identify in which zone the fire started.
- Addressable Fire Alarm:
This type of alarm is designed for larger, higher risk premises, an addressable fire alarm uses detection devices with unique ID’s (similar to serial numbers used to identify mobile phones and other devices). By using these ID’s it is able to identify problems not only by which zone but the location within that zone.
- Wireless Fire Alarm:
A wireless fire alarm is one of the latest designs that can be installed without much structural disruption, they work and perform in the same way as an addressable alarm but without the need for cabling to the panel.
Categories of fire alarm
Category M – Manual
The most standard type of fire alarm system, category M is a manual system where occupants of the building must physically activate the alarm upon discovering a fire by using brake glass points that will sound the alarm throughout the building to warn others of the danger.
Category P – Property
P1 – Detection installed everywhere in the building including any voids.
P2 – Detection is only installed in certain areas to manage a specific risk.
Category L – Life
L5 – Detection is only installed in areas in which a particular risk needs to be controlled.
L4 – Detection is only installed along escape routes such as stairways and corridors and
corresponding passage areas but not individual rooms.
L3 – Similar to L4 detection is placed along all escape routes leading from the interior of the premises to fire exits.
L2 – These alarms have detection in high-risk rooms and escape routes leading to fire exits, it provides advance warning of the existence of a fire in another area.
L1 – Known as maximum life protection automated fire alarm, an L1 system is the most
comprehensive category, detection is installed in every part of a building including large cupboard spaces, roofs and voids in construction.
Grades of Fire Alarms
Fire alarm grades range from A to F and are used to classify the quality of the system. Grades D to F are typically used in the majority of domestic premises requiring battery power and in some cases mains power supply.
Grade A – Fire detection and alarm that incorporates control and indicating equipment, installed to conform to BS5839: Part 1
Grade B – Fire detection and fire alarm system compromising of fire detectors other than smoke and heat alarms, fire alarm sounders, control and indicating equipment
Grade C – A System of detection and alarm sounders (which could be combined in the form of smoke alarms) connected to a common mains supply with back up and indication.
Grade D – Mains powered alarm with an integral stand-by power supply (battery back-up).
Grade E – Mains powered alarm with no stand-by power supply.
Grade F – Battery powered alarms.