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 56 of 56 matching glossary entries.
A fire alarm system in which each device has a unique address, letting the panel identify exactly which detector, call point or interface generated an event.
Makes fault-finding far faster than conventional zones — always keep the device schedule current.
The monitored centre receiving fire and fault signals from site transmission equipment and initiating the agreed response.
Test end-to-end with the ARC operator on the line — the dialler LED is not a test.
The raw reading an addressable detector returns to the panel (e.g. chamber obscuration), used to judge sensitivity, drift and contamination.
Trend values across service visits — a slowly rising value predicts a dirty-head callout.
Drawings updated to show what was actually installed — positions, addresses, routes and interfaces — rather than the original design intent.
A system that continuously draws air through sampling pipework to a central high-sensitivity detector, used for early warning or difficult spaces.
Airflow faults against the commissioning baseline usually mean broken pipe (high flow) or blocked holes/filter (low flow).
The UK code of practice for fire detection and alarm systems in non-domestic premises, covering design, installation, commissioning and maintenance recommendations.
Check the current edition and amendment before quoting any recommendation.
The UK code of practice for fire detection and alarm systems in domestic premises, including the grade and category conventions for dwellings.
The UK code of practice for actuation of release mechanisms for doors — the fire-alarm-to-door-release interface and its categories of actuation.
The European standards series for intruder and hold-up alarm systems, including the security grading framework.
An optical detector projecting a beam across a large space, signalling when smoke obscures it; alignment and building movement are its main maintenance issues.
The site-specific document mapping every alarm input to its required outputs (sounders, dampers, doors, plant, signalling); the reference for commissioning and testing.
An unversioned or missing matrix is a defect worth reporting in its own right.
Ring wiring returned to the panel so devices stay in communication from the other direction after a single break.
Radial (spur) wiring; devices beyond a break are lost, so a break shows as multiple missing devices downstream of one point.
Requiring two independent detectors in alarm before an output operates — standard practice ahead of suppression release.
The systematic proving of a completed installation against the design: device tests, cause-and-effect verification, sound levels, battery calculations and documentation.
An intruder activation corroborated by a second technology or event (sequential detection, audio or visual), used to support response policies.
A fire alarm system arranged in radial zones where the panel knows the affected zone but not the individual device.
Diagnosis relies on the zone chart and physically checking each device in the zone.
The area covered by a group of detection devices reported together, sized and bounded so responders can locate the origin of an alarm quickly.
A deliberate, indicated inhibition of a device, zone or output at the panel; a controlled impairment that must be recorded and reinstated.
Isolations left over from previous visits are a classic 'why didn't it work' finding.
The monitored interface releasing held-open fire doors on the mapped alarm condition; a released door must also close and latch fully to count.
Cause-and-effect logic requiring a second confirming trigger (same or second device) before a critical output such as plant shutdown or release operates.
A detector function that gradually adjusts for chamber contamination to hold sensitivity stable, flagging a fault when the adjustment limit is reached.
Alarm transmission over two independent paths (e.g. IP plus radio) so a single path failure does not silence the site; both paths need testing.
The European product standards for fire detection and alarm system components — panels, power supplies, detectors, call points, sounders, isolators and radio devices each have their own part.
The EN 54 part covering visual alarm devices (VADs), including the coverage classification system used to select and site them.
The fixed two-way speech system linking refuge points and fire telephones to a control position for use during evacuation and firefighting.
The resistor, capacitor or active unit at the end of a monitored circuit that lets the panel supervise the wiring for open and short circuit faults.
The programmed path allowing setting and unsetting without triggering an immediate alarm, with timed entry and exit periods.
The position equipment adopts on power or signal loss — open or closed varies by design strategy, so confirm the intended state before judging behaviour a fault.
The UK convention describing system objectives: L categories protect life, P categories protect property, M is manual-only; the category drives detection coverage.
Confirm the category from the design documentation before judging coverage — never assume.
A detector responding to the optical signature of flame (IR and/or UV), used for fast-developing fuel fires where smoke detection is too slow.
The UK domestic convention describing the equipment standard and power arrangements for dwelling alarm systems, set by the applicable domestic standard and risk.
An intruder alarm specified to a grade matching the assessed intruder skill and risk, driving supervision, tamper and signalling requirements.
Check insurer requirements before modifying anything on a graded system.
A detector operating on fixed temperature, rate of temperature rise, or both; used where smoke detection would false-alarm, at the cost of slower response.
A monitored input/output device connecting the fire system to other building systems — plant, dampers, lifts, security — under cause-and-effect control.
A loop device that disconnects a faulted section (typically a short circuit) so the remainder of the loop keeps operating.
When the panel shows 'isolator operated', the isolated section is your search area.
The site record of events, tests, faults, impairments and service visits; the system's legal and engineering memory.
The two-wire circuit connecting addressable devices to the panel, normally wired as a ring so devices remain in communication from either direction if the ring is broken at one point.
The break-glass device that lets an occupant raise the alarm manually; tested with the manufacturer's key so the frangible element is not broken.
A detector combining sensing principles (typically optical and heat) to improve discrimination between real fire signatures and nuisance sources.
A common first choice where steam or dust causes false alarms on pure optical heads.
A point detector sensing light scattered by smoke particles in its chamber; effective on smouldering fires, more prone to dust and steam nuisance alarms.
The UK scheme document applying the EN 50131 series to UK intruder alarm installations.
An evacuation strategy where areas evacuate in stages rather than simultaneously, driven by the cause-and-effect programme and voice alarm or staged signals.
A panel warning that a detector's reading has risen above normal but below the alarm threshold — often early contamination, steam or a developing condition.
The primary fire safety legislation for most non-domestic premises in England and Wales, placing duties on the responsible person including maintenance of fire safety systems.
Legislation — a legal duty, distinct from the recommendations of a code of practice.
The duty holder for fire safety in a premises under UK fire safety legislation, responsible for ensuring the system is maintained and impairments are managed.
Running a system or modified section for an agreed period before final acceptance to expose intermittent faults and nuisance alarms.
Assigning device addresses from the panel or programmer rather than physical switches; convenient, but replacements must be re-addressed deliberately.
After a soft-addressed replacement, run the device list and check for duplicates.
The measured loudness of the alarm signal at a location; verified during commissioning against the design targets for the premises and confirmed with a meter, not by ear.
Sizing batteries from standby current × standby duration plus alarm current × alarm duration, with the required safety margin, rounded up to a standard battery size.
A fire telephone handset outstation, typically for firefighting teams.
A fire signal from anything other than a real fire — cooking, steam, dust, works, faults or malicious operation; managed by matching detection type and siting to the environment.
A flashing warning device providing visual alarm indication, selected and sited using its rated coverage classification.
A one-engineer test mode where activated devices register at the panel (often without outputs) so devices can be proven while walking the site.
Always confirm test mode is cancelled before leaving — a panel left in test cannot raise a real alarm normally.
A geographical subdivision of the protected premises used to indicate the location of a fire or fault, shown on the panel and the zone chart.
The diagram at the panel showing zone boundaries and device locations so a stranger — fire officer or relief engineer — can locate any event quickly.