GA Fire Alarm key terms

A component such as a smoke detector, heat detector, manual pull station, or waterflow switch that sends a signal to the fire alarm control unit when it senses fire, smoke, or activation of suppression equipment.

A device that alerts occupants of a fire condition, including horns, speakers, strobes, chimes, and combination units. Audible and visible appliances must meet mounting height and candela requirements.

The central panel that receives signals from initiating devices, processes them under programmed logic, and activates notification appliances and auxiliary functions. Also called the FACU or fire alarm control panel.

A fire alarm architecture in which each device has a unique address, allowing the control unit to identify the specific device in alarm or trouble. Typically uses a signaling line circuit.

A fire alarm arrangement where devices are wired on zones rather than individually identified, so the panel reports only the zone in alarm. Simpler and less expensive but less precise for locating events.

A defined area or grouping of initiating devices reported as a single unit by the control unit. Zone size and arrangement are limited by code to aid responders in locating the source of an alarm.

The circuit connecting addressable devices to the control unit, carrying both power and data. Often called an SLC loop, it allows individual device communication and monitoring for faults.

The wiring path connecting conventional initiating devices to the control unit. Also called an IDC or detection zone circuit, it must be supervised against opens, shorts, and ground faults.

Continuous monitoring of circuit integrity so the system annunciates a trouble signal if wiring opens, shorts, or loses power. Supervised circuits protect against undetected failures that could prevent alarm operation.

A distinct audible and visual indication at the control unit that a fault exists, such as a circuit break, power loss, or device failure. It differs from an alarm signal in sound and purpose.

The signal produced by the system when an initiating device operates, intended to alert occupants and summon response. It has priority over supervisory and trouble signals on most systems.

A signal indicating a change in a monitored condition of a suppression system, such as a closed valve, low pressure, or low water level. It warns of impaired protection without indicating an actual fire.

A remote display panel that shows the location and status of alarms, supervisory conditions, and troubles, typically installed at a main entrance for fire department use. It helps responders identify the affected area quickly.

A manually operated initiating device that lets an occupant trigger an alarm. It must be mounted at accessible heights, be unobstructed, and be located along paths of egress travel.

A device that senses products of combustion. Common types include ionization, photoelectric, and air-sampling units, each suited to different fire types and environments.

A device that responds to temperature rise, either fixed-temperature, rate-of-rise, or combination. It is slower than smoke detection but resists nuisance alarms in smoky or dusty areas.

A detector installed in an HVAC duct to sense smoke moving through the air-handling system and initiate shutdown or alarm. It is not a substitute for area smoke detection in the protected space.

A control function that stops fans and closes dampers upon a duct detector alarm to limit smoke spread through the building. It is typically a separate relay function from general evacuation signaling.

An alarm signaling mode in which audible and visible notification is provided throughout the occupied area to alert all occupants. It is required for most occupancies and differs from private operating modes.

A device such as a horn or speaker that produces an alarm sound meeting required intensity and distinctiveness. Sound levels must exceed ambient noise by a specified margin in occupied spaces.

A strobe or similar device that provides a flashing light signal for hearing-impaired occupants and noisy environments. Candela rating and mounting height determine coverage area.

The continuous and unobstructed path of travel from any point in a building to a public way, including exit access, the exit itself, and exit discharge. Fire alarm design supports safe egress.

An automatic suppression system of piping and sprinkler heads that discharges water onto a fire. Heads operate individually by heat, and the system is monitored by the fire alarm panel.

A device on sprinkler piping that detects sustained water movement and sends an alarm signal to the fire alarm control unit. It must distinguish real flow from minor surges to avoid false alarms.

A device that monitors the open position of a suppression control valve and sends a supervisory signal if the valve is closed or partially closed. It protects against unnoticed impairment of water supply.

A fixed piping system with hose connections that allows firefighters or occupants to apply water for manual firefighting. Classes indicate whether it serves occupants, the fire department, or both.

An exterior connection where responding apparatus can pump water into a building's standpipe or sprinkler system. It must be accessible, clearly marked, and fitted with approved couplings.

An engineered arrangement of fans, dampers, and barriers that manages smoke movement to protect exit paths and aid evacuation. It may use pressurization, exhaust, or both.

A pump that boosts water pressure and flow for a suppression system when the public supply is inadequate. Its status and power source are typically monitored by the fire alarm system.

A suppression system using an electrically nonconductive gaseous or halocarbon agent that extinguishes fire without leaving residue. It is used for spaces where water damage is unacceptable, such as data centers.

A sprinkler system where piping stays dry until a detection event opens a valve, allowing water to fill the pipes before a head operates. It reduces accidental water discharge in sensitive areas.

A detection arrangement requiring two independent initiating devices to operate before suppression releases or an alarm is confirmed. It reduces accidental discharge and nuisance activation in special hazard areas.

A suppression system in which all open sprinkler heads discharge simultaneously when a detection system opens a control valve. It is used for high-hazard areas needing rapid, full-area water application.

A wet chemical system protecting commercial cooking equipment and exhaust hoods. It requires automatic and manual actuation, fuel shutdown, and coordination with the building fire alarm system.

A device that senses ultraviolet or infrared radiation from flames and responds rapidly to flaming fires. It is used in high-hazard areas where smoke or heat detection would be too slow.

The formal evaluation of fire alarm design documents by the authority having jurisdiction before installation. It verifies compliance with adopted codes, standards, and local amendments.

The organization or official responsible for enforcing code requirements and approving installations, often the fire marshal or building official. The AHJ may interpret code and require additional protection.

A documented functional test performed after installation to demonstrate that the system operates as designed and meets code. It is witnessed by the AHJ or its representative before the system is approved.

The recurring program of visual inspections, functional tests, and servicing required to keep a fire alarm system reliable after acceptance. Frequencies and methods are set by the applicable standard.

A document prepared by the installing contractor that records the system as built, including device locations, circuits, and operating sequence. It is required for acceptance and future maintenance reference.

The legal credentialing required for individuals and firms to design, install, or service fire alarm systems. Requirements vary by state and locality and often include examinations and continuing education.