Fire alarm components.

Control and indicating equipment (the panel)

The panel monitors every device, shows where an alarm or fault is and records events. It is the system’s brain and its reference point: zone lights or a text display, controls to silence and reset, and a logbook nearby. Most people only ever need to know how to read the panel, silence a test and report a fault.

Manual call points

The red boxes people operate to raise the alarm. They are positioned on escape routes and at exits so that someone leaving a building can raise the alarm on the way out. They are tested in rotation, usually weekly, as part of the user’s routine.

Sounders and visual alarm devices

Sounders give the audible warning, and must be loud enough to be heard above background noise in every area, including bedrooms where relevant. Visual alarm devices (VADs) add flashing lights for people who are hard of hearing or in noisy places, and are specified where the risk assessment calls for them.

Detectors

Smoke, heat and multi-sensor devices that sense a fire. See detector types.

Interfaces and extras

Systems can also control other things: releasing magnetic door holders so fire doors close, shutting down ventilation, or signalling to a monitoring centre. A red unit with a key switch, as pictured, is commonly used to isolate or control such outputs.

Documents

A logbook, zone plan, certificates and service records should be kept next to the panel. They are part of a compliant system as much as the hardware.