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Fire alarm engineer inspecting an alarm panel in a commercial building

Paraphrased from BS 5839-1:2025 Clause 3

Glossary

Plain-English reminders for common fire-alarm abbreviations and design terms.

Common terms

AFD
Automatic fire detector.
ASE
Ancillary safety equipment actuated by the fire system.
CIE
Control and indicating equipment—the fire alarm control panel.
MCP
Manual call point.
VAD
Visual alarm device.
Detection zone
A building subdivision used to indicate the area from which a fire signal originated.
Alarm zone
An area in which a common alarm signal is given.
Cause and effect
The defined relationship between input events and system outputs/actions.
Quiescent load
The normal electrical load when no alarm is present.
Maximum alarm load
The greatest load imposed on the supply during the alarm condition.
Source context: Paraphrased from BS 5839-1:2025 Clause 3. This page paraphrases the app’s quick-reference material and does not reproduce or replace the standard.