Fire Alarm communication with the fire service

For a fire alarm system to give the maximum benefit, the fire service needs to be called as quickly as possible on every occasion that it operates, unless, in order to avoid false alarms being passed to the fire service, the fire alarm has filtering arrangements, such as delayed timer output or coincidence signalling are appropriate
In occupied buildings, the primary means for calling the fire service needs to comprise a call to the fire brigade by occupants, using the 999 (or 112) public emergency call system. This is the case even if there is a means for automatic transmission of fire alarms to an alarm receiving centre, as any automatic system can fail at the time it is required to operate. It needs to be ensured that the fire alarm sounders cannot interfere with any emergency call to the fire service.

In the case of manual fire alarm systems, automatic transmission to an alarm receiving centre is usually unnecessary. When the building is unoccupied, the system will not respond to fire; when the building is
occupied, the call to the brigade from occupants will suffice. However, this would be decided after a fire risk assessment is conducted.

Fire alarms with an automatic means for transmission is only likely to be of benefit, as a secondary means of summoning the fire brigade, if factors such as the size or complexity of the building, or low level of occupancy, could result in a significant delay between discovery of fire and
summoning of the brigade, thereby warranting the duplication of the call to the fire service (i.e. with calls
made manually from the premises and automatically via an alarm receiving centre).

Since the objective of a Category L system is evacuation of occupants, rather than protection of property,
manual summoning of the fire service by occupants may, again, suffice, but again a fire risk assessment should be conducted to assist in making such decisions. However, if the early attendance of the fire brigade is likely to be essential to life safety in the event of fire (e.g. in hospitals), a secondary, automatic means of transmission might be warranted, unless there are adequate arrangements to ensure that there will be no delay at any time in manual summoning of the fire service by occupants.