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Fire Engineering Glossary

Technical terms spanning standards, manufacturers, commissioning, networking, testing and fault finding.

Technical guidance only. Confirm current project requirements against the applicable standards, legislation, system documentation and site-specific fire strategy.

Showing 7 of 7 matching glossary entries.

Power & batteries

Battery charger fault

A panel indication that the charging circuit or the batteries are outside limits — aged batteries, poor connections or a failed charger stage.

Check battery date codes and terminal voltage under load before condemning the charger.

Emergency lighting

Central battery system

Emergency lighting powered from a central battery installation rather than batteries in each fitting, concentrating maintenance at one point.

Fire detection

Commissioning

The systematic proving of a completed installation against the design: device tests, cause-and-effect verification, sound levels, battery calculations and documentation.

Emergency lighting

Duration test

A full rated-duration discharge of emergency lighting with every luminaire inspected at the end of the period, when failing batteries drop out.

Schedule so the building can tolerate discharged batteries during the recharge that follows.

Power & batteries

Power supply unit (PSU)

The monitored supply providing system power and battery charging; PSU faults commonly present as charger, battery or mains fault indications.

Power & batteries

Quiescent current

The current a system draws in normal standby, from panel and all devices together; the first input to any battery calculation.

Loop devices often dwarf the panel's own figure — never use the panel datasheet alone.

Power & batteries

Standby battery calculation

Sizing batteries from standby current × standby duration plus alarm current × alarm duration, with the required safety margin, rounded up to a standard battery size.