AL Fire Alarm key terms

Any device that starts a fire alarm signal, such as a smoke detector, heat detector, manual pull station, or waterflow switch. It reports a change in condition to the control unit.

A device that alerts occupants when an alarm occurs, including horns, strobes, chimes, speakers, and combination units. Placement and output are governed by audibility and visibility requirements.

A device on a signaling line circuit that has its own unique digital address, letting the panel identify the exact device in alarm or trouble rather than only the circuit.

A grouping of devices wired on a single circuit that reports to the panel as one unit. The panel shows the zone, not the individual device, when an alarm occurs.

A supervised circuit that carries digital communication between the control unit and addressable devices. It can power devices and carry data on the same pair of conductors.

Continuous monitoring of circuit wiring and components so the system detects opens, shorts, or ground faults and reports them as trouble conditions rather than remaining silently impaired.

A distinct audible and visual indication that a fault exists in the system, wiring, or power supply. It must be clearly different from an alarm signal so occupants do not confuse the two.

The output produced when an initiating device operates or a manual station is pulled. It commands notification appliances to sound and alerts the panel and any supervising station.

A device that senses smoke and initiates an alarm. Common types include ionization, photoelectric, and air-sampling units, each suited to different fire conditions and environments.

A device that responds to a rise in temperature, either fixed-temperature, rate-of-rise, or combination. It is often used where smoke detection would cause nuisance alarms.

A hand-operated initiating device that lets a person trigger the alarm. It must be located along the normal path of exit travel and mounted at an accessible height.

A device that detects water movement in a sprinkler system pipe and sends an alarm signal to the fire alarm panel when a sprinkler head or valve operates.

A device that monitors the position of a sprinkler control valve or other critical component and sends a supervisory signal when the valve is closed or moved from its normal position.

A signal indicating that a system or component has changed from its normal condition, such as a closed sprinkler valve or low air pressure, without indicating an actual fire alarm.

The central panel that receives signals from initiating devices, processes them, activates notification appliances, and displays alarm, trouble, and supervisory conditions. Also called the fire alarm control panel.

The maximum permitted distance between detectors and from a detector to a wall, based on the detector type, ceiling height, and manufacturer listings. It ensures timely detection across the protected area.

The floor area one detector is listed to protect, determined by its spacing rating and the ceiling configuration. It is used to calculate how many detectors a space requires.

The sound output of notification appliances, required to exceed ambient noise by a specified margin so occupants can hear the alarm above normal conditions.

The measure of light intensity produced by a visible notification appliance. Higher candela ratings are required in larger rooms or where occupants may be sleeping.

The property of an alarm signal being loud enough to be heard throughout the protected area, measured against ambient sound levels and adjusted for conditions such as closed doors.

The continuous route occupants follow to leave a building, including corridors, stairs, and exit doors. Manual stations and notification appliances are placed along it for early warning.

An unintended connection between a circuit conductor and ground. Fire alarm systems detect and annunciate ground faults because they can impair circuit operation and cause false alarms.

A defined area or circuit grouping used to identify where an alarm or trouble originates. Zones help responders locate the problem quickly within a large building.

A remote display panel that shows the status of zones or devices, such as alarm, trouble, and supervisory conditions, at a location away from the main control unit.

The state official whose office administers fire safety rules and licensing for fire alarm work in Alabama. Contractors must meet its registration and permitting requirements.

The process by which a jurisdiction formally adopts a model code or standard, such as NFPA 72, making it enforceable law within that jurisdiction, often with local amendments.

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

The organization or official responsible for approving installations and enforcing code, such as a local fire marshal or building official. Their interpretation governs acceptance of the work.

An official authorization to perform specified fire alarm work, issued by the local jurisdiction. Work generally may not begin until the permit is obtained and required fees are paid.

A documented test performed after installation to demonstrate the system operates as designed and meets code, typically witnessed by the authority having jurisdiction before the system is approved.

A visual and functional review of fire alarm equipment and installation to verify code compliance and proper condition, performed at intervals and during acceptance and routine maintenance.

Scheduled activities required by code to confirm that system components function correctly and to keep them in reliable operating condition throughout the life of the system.

A credential issued by Alabama authorizing a person or business to perform fire alarm work. Operating without the required license can result in penalties and contract problems.

The individual who meets examination and experience requirements and whose qualification supports a contracting firm's license. The firm's ability to operate depends on that person's standing.

A legally binding agreement between the contractor and the customer that defines the work, price, schedule, and responsibilities. Clear written terms help prevent disputes and protect both parties.

The written description of what the contractor will furnish and install, including devices, materials, and services. It defines the boundaries of the project and supports pricing and acceptance.

A written modification to an existing contract that adjusts the scope, price, or schedule. It must be agreed by both parties before the changed work proceeds.

A legal claim against property filed by a contractor or supplier who has not been paid for work or materials. Lien rules and deadlines are set by state law.

Final drawings updated to show the system as actually installed, including device locations and routing. They are used for future maintenance, testing, and modifications.

The relationship stating that voltage equals current multiplied by resistance. It is used to calculate loads, voltage drop, and current on fire alarm circuits.

The loss of voltage along a conductor caused by its resistance as current flows. Excessive drop can prevent notification appliances from operating at their rated output.

The total current drawn by devices on a circuit. It must stay within the panel's and wiring's rated capacity to ensure reliable operation of all connected equipment.

A wire or cable that carries electrical current between system components. Its size, insulation, and routing must meet code and support the circuit's load and voltage drop limits.

A raceway, usually metal or plastic, that protects and routes conductors. Proper fill, support, and grounding of conduit help maintain circuit integrity and code compliance.

Any channel designed to hold and protect wiring, such as conduit, tubing, or surface raceway. It keeps conductors organized and shielded from physical damage.

Connecting system components to earth or to a common reference point to limit voltage differences and provide a safe path for fault current, reducing shock and fire hazards.

Joining metal parts electrically so they remain at the same potential. It supports grounding and helps ensure fault current has a low-impedance path back to the source.

The opposition to current flow in a circuit, measured in ohms. It affects voltage drop, current draw, and the performance of detectors and notification appliances.

Secondary power, usually rechargeable batteries, that keeps the fire alarm system operating when normal building power is lost. Capacity must support the system for the required duration.

The normal source of electrical energy for the fire alarm system, typically the building's commercial power. It must be dedicated and meet code requirements for reliability.