There are two main types of category for fire alarm systems, and they are broken down into the following;
- Category L
- Category P
The objective of a category L system is to protect the occupants of a building. These are divided into 5 types;
- L5 should be based on a fire risk assessment and the assessment should clearly identify the areas or rooms which pose the risk. This category may form just part of an overall fire engineering solution. It must also be agreed with all the relevant authorities before it is installed.
- L4 covers all escape routes and circulation areas with automatic detection and manual call points.
- L3 covers the same as L4, but you now also protect any room that opens onto the escape route.
- L2 covers the same as L3, but you now also protect areas that are deemed to have a high risk, such as kitchens, boiler rooms etc.
- L1 covers the whole building, i.e. all areas within the building should be protected with automatic detection and manual call points.
The objective of a category P system is to protect the building. These are divided into 2 types;
- P2 covers areas that are deemed to be of high risk. A fire risk assessment should be carried out, to identify the high risk areas that would need to be protected with automatic detection.
- P1 covers all areas (as L1).
A category P system would normally be connected to an ARC (alarm receiving centre). This would give an early warning to alert the fire service, as a category P system may not always be manned by staff to raise the alarm.
All the above is a brief guide and you must always refer to the relevant standards (BS5839-1-2002) and any local authority regulations.