NICET FAS-I key terms

A system component such as a smoke detector, heat detector, manual pull station, or waterflow switch that signals the fire alarm control unit that a fire or other emergency condition exists.

An audible or visible device such as a horn, speaker, strobe, or chime that alerts occupants. These devices are connected to notification appliance circuits and are controlled by the fire alarm control unit.

The wiring path, also called an input circuit or zone, that connects automatic and manual initiating devices to the control unit. It may be conventional or addressable and is supervised for integrity.

The output circuit that supplies power to notification appliances. It is typically supervised for open and short conditions and may be Class A or Class B depending on wiring arrangement.

A system in which each initiating or output device has a unique address, allowing the control unit to identify the specific device in alarm or trouble rather than only the circuit or zone.

A system where devices are grouped on circuits or zones and the control unit reports an alarm by zone rather than by individual device. Common in smaller or older installations.

The unique numeric identifier assigned to a device on an addressable system. Addresses let the control unit report device-specific alarm and trouble conditions to the operator and in system records.

A defined area or grouping of devices reported as a single unit by the control unit. Zones may correspond to building areas, floors, or specific hazards, and are used for alarm annunciation.

Continuous monitoring of circuit wiring and system components for abnormal conditions such as opens, shorts, or grounds. Supervised circuits cause a trouble signal when integrity is compromised.

A circuit in which the wiring leaves the control unit and returns on a separate path, so a single open does not prevent operation of devices beyond the break. It provides a higher level of reliability.

A circuit where the wiring runs out from the control unit and terminates at the last device. A single open fault disables devices beyond the break, and the fault is reported as a trouble.

An audible and visual indication at the control unit that a fault exists, such as a circuit open, ground fault, power loss, or device failure. It is distinct from an alarm signal.

The signal produced by the system when an initiating device operates, indicating a fire or emergency condition. It activates notification appliances and is annunciated at the control unit.

An unintended connection between a system conductor and earth ground. Ground faults can disrupt operation and are typically detected and reported as a trouble condition by the control unit.

An automatic initiating device that senses smoke particles using ionization or photoelectric technology. It responds to products of combustion and signals the control unit when threshold conditions are met.

A smoke detector that uses a light source and photosensor to detect light scattered by smoke particles. It is generally more responsive to visible smoke from smoldering fires.

A smoke detector that uses a small radioactive source to ionize air in a chamber. Smoke entering the chamber changes the current, triggering an alarm. It often responds well to flaming fires.

An automatic device that responds to temperature rise, either fixed temperature or rate-of-rise, rather than smoke. It is used where smoke detection is unsuitable or as supplementary protection.

A heat detector that operates when the temperature increases faster than a predetermined rate. It can respond quickly to rapidly developing fires without waiting for a fixed temperature threshold.

A heat detector that operates when the sensed temperature reaches a predetermined set point. It is often combined with rate-of-rise sensing in a single device.

A manually operated initiating device that lets a person activate the fire alarm by pulling a handle or lever. It is typically installed along exit paths and near exits.

A device on a sprinkler system that detects sustained water flow and sends an alarm signal to the fire alarm control unit. It is usually set with a delay to avoid false alarms from surges.

A signal indicating an off-normal condition in a suppression system or other protected equipment, such as a closed valve or low pressure. It is distinct from alarm and trouble signals.

The central panel that receives signals from initiating devices, processes them, and controls notification appliances. It also monitors circuit integrity and annunciates alarm, supervisory, and trouble conditions.

A remote or local display panel that indicates the status of zones or devices, such as alarm, trouble, or supervisory conditions. It helps responders locate the area of an event.

The main source of electrical power for the fire alarm system, typically commercial AC power. Loss of primary power is monitored and reported as a trouble condition.

A backup power source, such as batteries or a generator, that keeps the system operational when primary power fails. It is sized to support the system for a specified duration.

The process of determining the battery capacity needed to support the fire alarm system during a specified standby period plus alarm time, accounting for loads and aging.

The use of sound and light to alert occupants. Audible signals must meet required sound levels, and visible signals such as strobes are required where hearing may be impaired or noise is high.

An addressable detector that can report analog values and status to the control unit, allowing sensitivity monitoring and drift compensation. It supports more precise alarm reporting than conventional devices.

A smoke detector installed in an HVAC duct to detect smoke being circulated through the building. It typically shuts down the air handler and sends an alarm signal to the control unit.

An addressable device that connects conventional initiating devices or control functions to an addressable system. It allows non-addressable equipment to be monitored or controlled by the panel.

An addressable output device that provides dry contacts to control or switch other equipment, such as door holders, dampers, or fans, in response to system conditions.

The system function that senses unintended connections between conductors and ground. Detection helps maintain circuit integrity and is reported as a trouble condition for service attention.

A feature that delays alarm processing briefly to confirm a detector signal, reducing false alarms from transient conditions. It must be used in accordance with applicable installation standards.

A system feature that causes an initial alarm at the control unit or a designated location before general notification, allowing staff to investigate. General alarm follows after a delay or confirmation.

A facility that receives signals from a protected premises fire alarm system and takes action, such as notifying the fire department. It may be central station, proprietary, or remote.