AK Fire Alarm key terms

The wiring path connecting automatic or manual initiating devices to the control unit, monitored so the panel can distinguish normal, alarm, open-circuit, and short-circuit conditions.

The circuit that supplies power and signal to horns, strobes, speakers, and other alerting devices, typically supervised for opens and shorts and often limited in the load it can carry.

A supervised circuit whose conductors leave the control unit and return on a separate path, so a single open or ground fault does not prevent operation of all devices on the circuit.

A supervised circuit that runs out from the control unit and ends at the last device, so a single open fault disables all devices beyond the break while a short may impair the whole circuit.

A resistor installed at the far end of a conventional Class B circuit that allows the panel to monitor wiring continuity and to detect a short across the zone.

A system in which each initiating or notification device has a unique address, letting the control unit report the identity and location of individual devices rather than only a circuit or zone.

A grouping of initiating devices sharing one circuit, where the panel reports only the zone that went into alarm rather than which specific device operated.

An initiating or notification appliance with a settable address that communicates individually with the control unit over the signaling line circuit and can be identified in reports and annunciation.

The addressable communication loop or path that carries digital data and power between the control unit and addressable devices, supporting individual device status reporting.

Continuous monitoring of a circuit or component for abnormal conditions such as opens, shorts, or grounds, with a trouble signal generated when the monitored condition departs from normal.

A distinctive audible and visual indication that a fault exists in the system, such as a wiring break, power loss, or device failure, requiring attention but not indicating an alarm condition.

A signal indicating that a monitored system component, such as a valve or sprinkler switch, has changed from its normal or required condition and needs human attention.

The output of the system that warns occupants of a fire or other emergency, typically produced by horns, strobes, or speakers and distinct from trouble or supervisory signals.

An automatic initiating device that senses combustion products such as visible or invisible particles and signals the control unit, commonly using ionization or photoelectric sensing technology.

A smoke detector that responds when smoke particles scatter or block a light beam within its sensing chamber, generally more responsive to visible smoldering smoke than to fast flaming fires.

A smoke detector that responds when combustion particles alter the flow of ions between charged plates, generally more responsive to small particles from fast flaming fires than to large visible smoke.

The maximum distance permitted between smoke or heat detectors, and between detectors and walls, based on listed spacing and the ceiling height and configuration of the protected area.

An automatic initiating device that responds to a fixed temperature threshold, a rapid rate of temperature rise, or both, rather than to smoke or combustion products.

A detector whose sensing element responds to conditions at a specific location, as opposed to a projected-beam or line-type detector that senses along a path or area.

A hand-operated initiating device mounted along an exit path so occupants can manually activate the fire alarm when they observe a fire or other emergency.

A device such as a horn, bell, or speaker that produces an alarm sound intended to alert occupants, subject to sound pressure requirements and ambient noise considerations.

A strobe or other light-emitting device that provides a visual alarm signal, especially for occupants who are deaf or hard of hearing or in high-noise environments.

The measure of luminous intensity of a visible notification appliance, used to select strobes whose light output meets the required level for the room size and mounting conditions.

The coordinated flashing of visible notification appliances on a circuit or system so that strobes flash together within permitted timing limits, reducing seizure risk and meeting code requirements.

The sound pressure level produced by alarm notification appliances, measured relative to ambient noise, that must be sufficient to alert occupants throughout the protected area.

A measure of sound intensity, usually expressed in decibels, used to evaluate whether alarm signals exceed ambient noise by the required margin in a protected space.

The reduction in voltage along circuit conductors caused by resistance and load current, which must be calculated to ensure notification appliances receive adequate operating voltage at the end of a run.

The normal source of commercial electrical power for the fire alarm system, typically a dedicated branch circuit that supplies the control unit and its charging equipment.

The standby source, usually rechargeable batteries or an engine-driven generator, that powers the fire alarm system when the primary power fails.

Rechargeable batteries and charging circuitry that provide standby and alarm power for a specified duration when normal building power is interrupted.

The central panel that receives signals from initiating devices, processes them, activates notification appliances, and annunciates alarm, trouble, and supervisory conditions.

A remote or local display panel that indicates the status and location of alarm, trouble, and supervisory conditions, often used at entrances for responding personnel.

The required vertical elevation for devices such as manual pull stations and notification appliances, set so they are reachable or perceivable by occupants including those with disabilities.

A visual and functional check of fire alarm system components to confirm they are installed, unobstructed, and in the condition required by the applicable codes and standards.

The operational verification of system components and functions, performed at required intervals, to confirm that devices, circuits, and control functions respond as intended.

The ongoing work of repairing, cleaning, adjusting, or replacing fire alarm components so the system continues to perform reliably between inspections and tests.

A document prepared at installation that records the system configuration, device locations, and design details, serving as a baseline for later inspection, testing, and maintenance.

Drawings updated to reflect the actual installed configuration of the fire alarm system, including device locations and circuit routing, used for maintenance and future modifications.

The process of examining submitted fire alarm design documents for compliance with applicable codes, standards, and local requirements before installation is approved.

The organization, office, or individual responsible for enforcing code requirements and approving equipment, installations, and procedures for the fire alarm system.

The state-adopted fire prevention regulations, based on a model fire code with state amendments, that govern fire protection and life safety requirements in Alaska jurisdictions.

The National Fire Alarm and Signaling Code, which sets requirements for the design, installation, testing, inspection, and maintenance of fire alarm and signaling systems.

The National Electrical Code, which establishes requirements for electrical wiring, overcurrent protection, grounding, and installation methods that apply to fire alarm circuits.

The Life Safety Code, which addresses means of egress, occupancy classification, and fire protection features including when and where fire alarm systems are required.

The category assigned to a building or space based on its use, which determines the fire alarm, detection, and egress features that the life safety code requires.