NY Fire Alarm Installer cheat sheet

NFPA 72 (National Fire Alarm and Signaling Code) governs design, installation, testing, and maintenance; NFPA 70 (NEC) Article 760 governs fire alarm circuit wiring.

NYC Fire Code Chapter 9 and NYC Building Code Chapter 9 (Section 907) establish when a fire alarm system is required; the FDNY is the AHJ for plan review, permits, and acceptance testing.

NFPA 101 (Life Safety Code) sets occupancy-based alarm and means-of-egress requirements that drive system type and notification method.

Equipment must be listed for fire alarm use: control units UL 864, smoke detectors UL 268, heat detectors UL 521, audible appliances UL 464, visible appliances UL 1971.

Installations must follow the manufacturer's published instructions and the terms of the listing; where documents conflict, the most restrictive requirement governs.

New or modified systems require FDNY plan review/approval before installation and a witnessed acceptance test before being placed in service.

NFPA 72 requires a Record of Completion and a Record of Inspection and Testing, delivered to the owner and made available to the AHJ.

Impairments follow a documented program: notify the AHJ and occupants, post a fire watch, and record the impairment and restoration.

The enforceable edition of NFPA 72 and NFPA 70 is the edition referenced by the adopted NYC codes, not the newest published edition.

Protected premises (local) systems signal only inside the building; supervising station types are auxiliary, remote station, proprietary, and central station (NFPA 72 Chapter 26).

A central station must be listed (UL 827), staffed 24 hours a day, and receive signals over two independent, supervised communication paths.

Signals are classified as alarm, supervisory, trouble, and other/off-normal; each must be annunciated distinctly at the control unit and any supervising station.

NYC high-rise threshold: an occupied floor more than 75 ft above the lowest level of fire department vehicle access triggers voice evacuation, fire command center, and 2-hour circuit survivability.

Occupancy group (Assembly, Business, Educational, Institutional, Mercantile, Residential, Storage, Industrial, High Hazard) sets detection, public vs private notification mode, and voice requirements.

Assembly occupancies with an occupant load of 300 or more typically require a fire alarm system; exact thresholds are tabulated by occupancy group in the building code.

NFPA 72 Chapter 24 covers emergency communications systems: in-building voice evacuation, mass notification, and two-way emergency communication.

Conventional (zone) systems report by circuit or zone; addressable systems report each device individually over a signaling line circuit (SLC).

Manual systems provide pull stations plus notification only; automatic systems add detection and typically interface with sprinkler waterflow, HVAC, and elevator recall.

Spot smoke detectors on smooth ceilings: 30 ft (9.1 m) maximum spacing, last detector within 15 ft (4.6 m) of walls or partitions, and at least 4 in. (100 mm) from the wall.

Heat detectors: 50 ft (15.2 m) spacing and 25 ft (7.6 m) from walls as a baseline for 10-ft ceilings; use the device's listed spacing and reduce it for higher ceilings.

Keep smoke detectors at least 36 in. (0.9 m) from HVAC supply diffusers and out of dead-air pockets; on peaked ceilings, place a detector within 3 ft horizontally of the apex.

Duct smoke detectors are required in supply ducts over 2,000 cfm and return ducts over 15,000 cfm; install per the airflow arrow, away from bends and ahead of filters and branches.

Manual fire alarm boxes: within 5 ft (1.5 m) of the exit door opening, 42 to 48 in. (1.07 to 1.22 m) above finished floor, visible and unobstructed along the path of egress.

Waterflow switches must annunciate an alarm within 90 seconds of sustained flow; sprinkler control valve tamper switches produce supervisory, not alarm, signals.

Elevator recall requires smoke detection in each elevator lobby, the machine room, and the hoistway; the lobby detector typically recalls cars to an alternate floor.

Projected-beam smoke detectors are listed up to 60 ft (18.3 m) spacing and mounted roughly 1 to 3 ft below the ceiling; air-sampling systems must follow the manufacturer's pipe-design calculation.

Ceilings higher than the listed reference require spacing adjustment per NFPA 72 tables; detector location must also account for ceiling jets and obstructions.

Audible appliances must produce 15 dBA above average ambient sound, or 5 dBA above ambient where ambient exceeds 105 dBA, measured in the occupied area.

Sleeping areas: at least 75 dBA at the pillow and 15 dBA above ambient; a 520 Hz low-frequency tone is required for sleeping-area alarms.

Visible appliances mount 80 to 96 in. (2.03 to 2.44 m) above finished floor to the appliance; candela is sized by room dimensions and ceiling height (about 15 cd for a 20x20 ft room, 30 cd for 30x30, 60 cd for 40x40 at a 10-ft ceiling).

Visible appliances in the same field of view must be synchronized and flash 1 to 2 times per second.

Public mode notifies all occupants generally; private mode notifies staff or emergency responders only, and both change required sound levels and coverage.

The evacuation tone is temporal-3: three 0.5-second pulses separated by 0.5-second pauses, then a 1.5-second pause, repeating.

Voice systems require intelligible speaker coverage in all occupied areas and 24 hours standby plus 15 minutes of alarm secondary power.

Notification appliance circuits are supervised and power-limited, and must deliver at least each appliance's listed minimum operating voltage at the last device.

ADA and ICC A117.1 require visible alarms in common areas, restrooms, and other covered spaces of applicable occupancies.

Class B: supervised two-wire circuit with an end-of-line resistor; a single open disables all devices beyond the break and produces a trouble.

Class A: supervised circuit with a return path to the control unit; a single open or ground fault does not prevent any device from operating.

NEC Article 760 governs fire alarm conductors: power-limited fire alarm (PLFA) Class 2 and 3 circuits, separation from power wiring (2 in. or a listed barrier), and conductor listing.

Cable listing follows the environment: FPL for general use, FPLR for risers, FPLP for plenums, subject to the raceway and environmental rules of the adopted electrical code.

The control unit's AC supply must be a dedicated, unswitched branch circuit with a lockable disconnecting means marked "FIRE ALARM CIRCUIT CONTROL".

High-rise and partial-evacuation systems require 2-hour circuit integrity protection for alarm and voice circuits, using CI cable or a 2-hour rated enclosure.

Addressable signaling line circuits are typically Class A (Style 6/7) with isolator modules that limit a single short to one segment.

Supervisory circuits such as valve tamper and duct detector off-normal must annunciate as supervisory, distinct from alarm and trouble.

NAC voltage drop: cumulative load current times the loop resistance must not drop voltage below the listed minimum operating voltage of the last appliance.

Secondary power capacity: 24 hours standby plus 5 minutes of alarm for commercial protected-premises systems per NFPA 72 Table 10.6.7.2.1.

In-building voice evacuation systems require 24 hours standby plus 15 minutes of alarm; other occupancy and system classes are tabulated in the same table.

Battery sizing: Ah = (standby current x 24 h) + (alarm current x alarm hours), then apply an aging/derating factor (commonly 1.25).

Use the battery's 20-hour capacity rating plus the manufacturer's derating data for temperature and end-of-discharge voltage.

Use worst-case loads: total standby current of control unit, annunciators, and devices, plus the full alarm current of every notification appliance circuit.

Sealed lead-acid batteries are typical; 12 V blocks in series build 24 V systems, and charging voltage/current limits come from the battery and control unit data.

Battery leads must be supervised so a missing or open battery registers as a trouble; a low-battery condition must annunciate before the battery is depleted.

A loss of primary AC power must be annunciated, and battery/charger calculations are submitted with the design and verified at acceptance.

Acceptance testing requires 100 percent of initiating devices, notification appliances, and interface functions to be tested; sampling is not permitted.

Verify primary power, secondary power, and a simulated 24-hour standby period with full alarm load as part of acceptance.

Interfaces to test: elevator Phase I/II recall, HVAC shutdown from duct detectors, sprinkler waterflow and tamper, door hold-opens, access control release, smoke control, and fire command center functions.

Duct detector testing must confirm both alarm annunciation and the associated air-handling unit shutdown.

Audibility is measured with a sound level meter; visible appliances are verified for coverage and synchronization.

Deliver to the owner the Record of Completion, as-built drawings, sequence of operations, battery calculations, and manufacturer's instructions.

Pre-test checks: device addresses and labels match plans, circuits are free of opens and grounds, and notification loads are within control unit capacity.

Any modification requires retesting of the affected devices and all interfaced functions before the system returns to service.

Acceptance testing is witnessed by the FDNY and documented; failed items are corrected and retested.

NFPA 72 Chapter 14 governs inspection, testing, and maintenance, with frequencies in Table 14.4.3.2; initiating devices and notification appliances are functionally tested at least annually.

Smoke detector sensitivity must be verified within one year of installation and at subsequent intervals; out-of-range units are cleaned, adjusted, or replaced.

Batteries require periodic inspection and load testing; replace a battery that cannot carry the calculated standby-plus-alarm load.

Records are retained until the next test and made available to the AHJ, with the owner keeping documentation on site.

Impairments: notify occupants and the FDNY, establish a fire watch, and document both the impairment and the restoration.

Test methods: listed aerosol or canned smoke for smoke detectors, a listed heat source for heat detectors, remote test port for duct detectors, key/operation for pull stations, activation for NACs.

Inspection and testing is performed by qualified, licensed personnel, and results are recorded on the Record of Inspection and Testing.

Reacceptance testing is required after alteration, repair, or relocation of devices or circuits.

The documentation set includes Record of Completion, Record of Inspection and Testing, as-builts, sequence of operations, battery calculations, and equipment data sheets.