NICET FAS-I cheat sheet

NFPA 72 defines a fire alarm system as the combination of initiating devices, notification appliances, control equipment, and interconnecting wiring that detects and signals a fire condition.

Initiating device circuits (IDCs) are either Class A (return loop, survives one open) or Class B (single path, one open disables the circuit); the class letter describes survivability, not technology.

Signaling Line Circuits (SLCs) are addressable and support Class A or Class B wiring; each addressable device occupies a discrete address reported to the control unit.

Notification Appliance Circuits (NACs) are Class A or B power circuits; voltage drop calculations must confirm the last appliance receives at least its listed minimum operating voltage.

Detector spacing on smooth ceilings is typically a 30 ft (9.1 m) nominal radius per NFPA 72 unless the listing or manufacturer allows otherwise; spacing is measured from walls and obstructions.

Spot-type heat detectors use lower spacing ratings than smoke detectors and are selected by listing; fixed-temperature, rate-of-rise, and combination types respond to different phenomena.

A supervisory signal indicates an off-normal condition of a system component (valve closed, power loss) and must be visually and audibly distinct from an alarm signal.

Trouble signals indicate circuit faults or component failures and are required to be annunciated at the control unit; the system must remain functional for unaffected circuits.

Alarm, supervisory, and trouble signals must be distinguishable by audible and visual means; a common trouble sound is a distinct pulsing tone rather than the steady alarm tone.

NFPA 72 requires that a fire alarm system be installed and maintained so that a single open or ground fault on a Class B circuit is annunciated as a trouble without preventing alarm operation on remaining devices.

Class A circuits provide a redundant path; a single open does not prevent operation of any device on the loop, but the fault must still be annunciated.

Addressable systems use device-level addresses; conventional zones report by zone, so troubleshooting requires field tracing of the zone wiring.

Smoke detector spacing rules are based on ceiling height and configuration; high ceilings and sloped ceilings require adjustment of the listed spacing per NFPA 72.

Duct smoke detectors are installed in air-handling systems to detect smoke being circulated and to initiate shutdown of the unit where required by the design.

A waterflow switch on a sprinkler system is an initiating device that reports a flow condition as an alarm; a valve tamper switch reports a supervisory condition.

Notification appliance audibility must meet the design sound pressure level; the code requires a minimum sound level above ambient in occupiable areas, with higher levels in sleeping areas.

Visible notification appliances must be spaced and mounted per the listing and NFPA 72; the candela rating and mounting height determine coverage.

Battery calculations must demonstrate that the secondary supply can operate the system for the required standby period plus the required alarm period at the calculated load.

The fire alarm control unit (FACU) provides power, monitoring, and control; remote annunciators and power supplies extend the system and must be supervised.

Initiating devices include manual pull stations, smoke detectors, heat detectors, waterflow switches, and other listed devices; each has specific mounting height and location rules.

Manual fire alarm boxes must be mounted at a height accessible to occupants, typically 42 to 48 inches to the operating handle, and located along the path of egress.

Smoke detectors should be located away from air supply diffusers and other conditions that prevent smoke from reaching the sensing chamber.

Addressable systems use a signaling line circuit; conventional systems use initiating device circuits; the two cannot be mixed on the same circuit without a listed interface.

Supervisory devices include valve tamper switches, low-air switches, and fire pump status switches; their signals must be distinct from alarm and trouble.

Trouble signals must be indicated within a specified time after a fault occurs; the control unit must also indicate the location and type of fault where the system is addressable.

The system must be provided with a means to silence notification appliances while retaining the alarm condition and visual indication until the system is reset.

Ground fault detection is required on the system; a ground fault on a circuit must be annunciated as a trouble and located where the system is capable of doing so.

NFPA 72 requires that the system be tested after installation and at intervals thereafter; acceptance testing verifies that each device and circuit performs as designed.

The test plan should include a device-by-device test of initiating devices and a verification that each notification appliance operates when the system is in alarm.

Record-of-completion documentation includes the as-built drawings, device list, battery calculations, and the testing and inspection records.

A fire alarm system must be monitored by a supervising station or otherwise arranged so that signals are received and acted upon; the method of monitoring is part of the design.

The system must have a primary and secondary power supply; the secondary supply is typically batteries and must be sized for the standby and alarm loads.

Addressable device addressing must be documented; duplicate addresses cause faults and prevent proper annunciation of the affected device.

A trouble condition on a notification circuit must not prevent the remaining notification appliances from operating where the circuit is Class A or where the design provides for it.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

Inspection and testing records must be maintained and made available to the authority having jurisdiction upon request.

Smoke detector sensitivity is listed in percent per foot obscuration; field testing verifies that the detector responds within its listed range.

Heat detector listing temperatures are selected above the expected ambient temperature; a detector rated too close to ambient causes nuisance alarms.

A waterflow switch must be installed so that it operates on a flow of the required rate; the switch is tested by opening the inspector's test connection.

Notification appliance circuits must be designed so that the voltage at the last appliance is at least the listed minimum; voltage drop is calculated using the circuit resistance and load current.

The candela rating of a visible appliance determines its coverage area; a higher candela rating generally covers a larger area at the same mounting height.

Audible appliances must produce a sound level that is distinguishable from ambient noise; the required level is higher in sleeping areas than in other occupiable spaces.

A fire alarm system must be provided with a means to disconnect the primary power without affecting the secondary supply, and the secondary supply must be capable of operating the system.

Supervisory signals must be annunciated within the time specified by the code and must be distinguishable from alarm and trouble signals.

The authority having jurisdiction may require additional testing or documentation beyond the minimum code requirements; the design must accommodate that.

A ground fault on a fire alarm circuit is a trouble condition; the system must detect and annunciate it, and the fault must be located where the system is capable.

An open circuit on a Class B IDC disables the devices beyond the break; on a Class A circuit the devices remain operational but the fault is annunciated.

A short circuit on a notification circuit may prevent appliances from operating; the circuit design must account for the fault tolerance required by the class.

Addressable devices report their status individually; a device that fails to respond is annunciated as a trouble with its address.

A supervisory condition such as a closed valve must be annunciated distinctly and must not be confused with an alarm or trouble signal.

The control unit must be capable of being reset only after the alarm condition has been cleared; reset restores the system to normal supervision.

Alarm silencing must not prevent the transmission of the alarm signal to the supervising station or the operation of other required functions.

The system must be arranged so that a single break in the wiring does not prevent the alarm signal from being transmitted where the design requires it.

Battery calculations must include the quiescent load and the alarm load, with the required standby and alarm times, and must account for battery derating.

NFPA 72 requires that the system be inspected and tested at the intervals specified in the code; the frequency depends on the component and the system type.

Smoke detectors are tested for sensitivity and response; the test method must not damage the detector and must verify that it operates within its listed range.

Notification appliances are tested for audibility and visibility; the test must confirm that the required sound level and coverage are achieved.

The testing and inspection report must record the results, including any deficiencies and the corrective actions taken.

The authority having jurisdiction may witness acceptance testing and may require that the system be tested in the presence of the AHJ.

A fire alarm system must be maintained in accordance with the manufacturer's instructions and the code; maintenance records must be retained.

The system must be provided with a means to test the notification appliances without activating the alarm transmission where the design permits.

Addressable systems must be tested to verify that each device reports its correct address and that the control unit annunciates the correct location.

The record of completion must be updated when the system is modified; changes to the system must be documented and tested.

The fire alarm control unit must be located in an area that is accessible to authorized personnel and protected from damage; the location is part of the design.

Remote annunciators must be supervised and must indicate the same conditions as the main control unit where required.

Power supplies for notification appliances must be listed for fire alarm use and must be supervised for failure.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

Initiating devices must be located so that they are accessible for testing and maintenance and so that they detect the conditions they are intended to detect.

Smoke detectors in sleeping areas must be located to provide the required protection; the location and spacing are specified by the code.

Heat detectors are selected for the expected rate of temperature rise and the maximum ambient temperature; the listing temperature must be above ambient.

Manual pull stations must be located so that they are unobstructed and along the path of egress; the mounting height is specified by the code.

The system must be designed so that the alarm signal is distinguishable from the supervisory and trouble signals by audible and visual means.

A fire alarm system must be provided with a primary power supply and a secondary power supply; the secondary supply must be capable of operating the system for the required time.

The secondary supply is typically a battery set; the battery must be sized for the standby load plus the alarm load and must be derated for temperature and age.

The battery charger must be capable of restoring the battery to full charge within the required time after a discharge.

The system must be provided with a means to disconnect the primary power without affecting the secondary supply; the secondary supply must be monitored for failure.

A trouble signal must be annunciated when the secondary supply fails or when the battery is disconnected.

The primary power supply must be dedicated and must be protected by a circuit breaker or fuse that is accessible only to authorized personnel.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

The control unit must be capable of operating the notification appliances at their listed voltage and current; the design must account for voltage drop.

The system must be tested to verify that the secondary supply operates the system for the required time under the calculated load.

NFPA 72 requires that the system be inspected and tested at the intervals specified; the frequency depends on the component and the system type.

Smoke detectors are tested for sensitivity and response; the test method must not damage the detector and must verify that it operates within its listed range.

Notification appliances are tested for audibility and visibility; the test must confirm that the required sound level and coverage are achieved.

The testing and inspection report must record the results, including any deficiencies and the corrective actions taken.

The authority having jurisdiction may witness acceptance testing and may require that the system be tested in the presence of the AHJ.

A fire alarm system must be maintained in accordance with the manufacturer's instructions and the code; maintenance records must be retained.

The system must be provided with a means to test the notification appliances without activating the alarm transmission where the design permits.

Addressable systems must be tested to verify that each device reports its correct address and that the control unit annunciates the correct location.

The record of completion must be updated when the system is modified; changes to the system must be documented and tested.

The fire alarm control unit must be located in an area that is accessible to authorized personnel and protected from damage; the location is part of the design.

Remote annunciators must be supervised and must indicate the same conditions as the main control unit where required.

Power supplies for notification appliances must be listed for fire alarm use and must be supervised for failure.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

Initiating devices must be located so that they are accessible for testing and maintenance and so that they detect the conditions they are intended to detect.

Smoke detectors in sleeping areas must be located to provide the required protection; the location and spacing are specified by the code.

Heat detectors are selected for the expected rate of temperature rise and the maximum ambient temperature; the listing temperature must be above ambient.

Manual pull stations must be located so that they are unobstructed and along the path of egress; the mounting height is specified by the code.

The system must be designed so that the alarm signal is distinguishable from the supervisory and trouble signals by audible and visual means.

A fire alarm system must be provided with a primary power supply and a secondary power supply; the secondary supply must be capable of operating the system for the required time.

The secondary supply is typically a battery set; the battery must be sized for the standby load plus the alarm load and must be derated for temperature and age.

The battery charger must be capable of restoring the battery to full charge within the required time after a discharge.

The system must be provided with a means to disconnect the primary power without affecting the secondary supply; the secondary supply must be monitored for failure.

A trouble signal must be annunciated when the secondary supply fails or when the battery is disconnected.

The primary power supply must be dedicated and must be protected by a circuit breaker or fuse that is accessible only to authorized personnel.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

The control unit must be capable of operating the notification appliances at their listed voltage and current; the design must account for voltage drop.

The system must be tested to verify that the secondary supply operates the system for the required time under the calculated load.

NFPA 72 requires that the system be inspected and tested at the intervals specified; the frequency depends on the component and the system type.

Smoke detectors are tested for sensitivity and response; the test method must not damage the detector and must verify that it operates within its listed range.

Notification appliances are tested for audibility and visibility; the test must confirm that the required sound level and coverage are achieved.

The testing and inspection report must record the results, including any deficiencies and the corrective actions taken.

The authority having jurisdiction may witness acceptance testing and may require that the system be tested in the presence of the AHJ.

A fire alarm system must be maintained in accordance with the manufacturer's instructions and the code; maintenance records must be retained.

The system must be provided with a means to test the notification appliances without activating the alarm transmission where the design permits.

Addressable systems must be tested to verify that each device reports its correct address and that the control unit annunciates the correct location.

The record of completion must be updated when the system is modified; changes to the system must be documented and tested.

The fire alarm control unit must be located in an area that is accessible to authorized personnel and protected from damage; the location is part of the design.

Remote annunciators must be supervised and must indicate the same conditions as the main control unit where required.

Power supplies for notification appliances must be listed for fire alarm use and must be supervised for failure.

The system must be arranged so that a single fault does not prevent the alarm signal from being transmitted to the supervising station.

Initiating devices must be located so that they are accessible for testing and maintenance and so that they detect the conditions they are intended to detect.

Smoke detectors in sleeping areas must be located to provide the required protection; the location and spacing are specified by the code.

Heat detectors are selected for the expected rate of temperature rise and the maximum ambient temperature; the listing temperature must be above ambient.

Manual pull stations must be located so that they are unobstructed and along the path of egress; the mounting height is specified by the code.

The system must be designed so that the alarm signal is distinguishable from the supervisory and trouble signals by audible and visual means.