NM Fire Alarm cheat sheet

NFPA 72 governs initiating devices, notification appliances, circuits, supervising station systems, and inspection/testing/maintenance; installation wiring itself is governed by NEC Article 760.

A protected premises (local) system sounds evacuation signals only within the protected building and has no automatic off-premises transmission.

A central station system transmits signals to a listed, privately operated supervising station staffed continuously and providing runner service under contract.

A remote supervising station system transmits to a constantly attended location operated by the owner or a public agency, not a commercial central station.

Auxiliary systems connect fire alarm initiating circuits to a public fire service communication system (municipal fire alarm box circuits).

Addressable systems identify each device individually; conventional (zone) systems report by circuit or zone, so a zone covers all devices on that pair of conductors.

Detector spacing on smooth ceilings is based on the listed spacing of the detector (commonly 30 ft for spot smoke detectors), then adjusted for ceiling height and configuration.

Required system features are established by the adopted building code and the occupancy chapter of NFPA 101, not by NFPA 72 alone; NFPA 72 defines how those features are installed and maintained.

Smoke detectors: ionization responds faster to flaming fires and small particles; photoelectric responds faster to smoldering fires and larger particles; combination units use both technologies.

Spot-type smoke detector spacing: 30 ft listed spacing on smooth ceilings, reduced for ceiling heights above 10 ft per the height/spacing curve; detectors must be within 21 ft of any point on the ceiling.

Duct smoke detectors are required where air handling systems are over 2,000 cfm and are for equipment shutdown/supervision, not general area detection; sampling tubes must span the duct width.

Heat detectors: fixed-temperature, rate-of-rise, or combination; rate-of-rise units are not used where normal temperature changes exceed 15 °F per minute.

Manual pull stations must be mounted 42 to 48 in. above the finished floor, within 5 ft of the exit door, and on the latch side of the door.

Notification appliance circuits (NACs) must be electrically supervised; audible signals must be at least 15 dBA above ambient or 5 dBA above maximum ambient lasting over 60 seconds, whichever is greater.

Public mode audible requirements are measured at 60 in. above the floor (or maximum sound pressure level) with all doors closed; private mode is 10 dBA above ambient in occupied areas.

Visible notification appliances must be synchronized when in the same viewing area, and spacing follows the candela rating and mounting height tables (wall-mounted 80 in. to 96 in. AFF).

Primary (commercial) power source must be a dedicated branch circuit supplying the fire alarm equipment, connected ahead of other loads, with circuit disconnecting means clearly marked and protected from accidental operation.

Secondary power supply capacity: 24 hours of standby followed by 5 minutes of alarm for commercial occupancies; 24 hours plus 5 minutes for central station; 60 hours plus 5 minutes where the system serves mercantile or where required by code.

Battery calculation: required capacity (Ah) = (standby current × standby hours) + (alarm current × alarm hours), then multiply by a 1.20 derating factor and select a battery rated for the calculated capacity.

Voltage drop on NAC and IDC circuits: Vd = 2 × L × I × R per 1,000 ft using the conductor's resistance; total drop must leave at least the minimum operating voltage at the last device.

Class B (Style B/D) circuits are two-wire with a single path; a single open fault disables devices beyond the break, and the circuit must be supervised for opens, grounds, and shorts.

Class A (Style D/E) circuits return to the panel, so a single open fault does not disable any device; Class A is required for notification circuits in high-rise and certain occupancies.

Surge protection is required on circuits leaving the building and on AC power where the panel is not provided with transient protection; ground fault detection must be provided on all initiating and notification circuits.

All fire alarm power-limited circuit conductors must be separated from non-power-limited and Class 1 circuits by at least 2 in. or by a barrier, and must be identified at both ends and at junctions.

Article 760 covers fire alarm systems: 760.41 for non-power-limited fire alarm circuits (NPLFA) and 760.121 for power-limited fire alarm circuits (PLFA).

NPLFA conductors must be minimum 14 AWG copper (or 12 AWG aluminum) and installed in raceway or as part of a listed cable assembly; PLFA conductors follow the manufacturer's listing and 760.179.

FPL, FPLR, and FPLP cables are the permitted fire alarm cable types; FPLP (plenum) is required in environmental air spaces, FPLR (riser) in vertical shafts, and FPL in other locations.

Fire alarm cables may not be installed in the same raceway, cable, or box with conductors of other systems unless separated by a barrier or where permitted by 760.139 and 300.8.

Non-power-limited fire alarm circuit conductors must be installed in raceway or listed cable and must be separated by at least 2 in. from power-limited circuits or use a listed barrier.

Fire alarm system conductors must be mechanically protected where exposed to physical damage, and raceway fill follows Chapter 9 tables; conductor ampacity and derating follow Article 310.

The fire alarm circuit disconnecting means must be a listed indicating-type switch or circuit breaker, must be red, and must be marked "FIRE ALARM CIRCUIT CONTROL" and accessible only to authorized personnel.

Grounding and bonding of fire alarm equipment follows Article 250; a separate equipment grounding conductor must be run with the fire alarm circuit and bonded at the service.

Acceptance testing must be performed by a qualified person and documented before the system is placed in service; the record of completion (NFPA 72 Figure 7.8.2) is signed by the installing contractor and the owner's representative.

Initiating devices are tested annually; smoke detectors are tested annually (or per manufacturer), and duct detectors are tested annually with the air handling system operating.

Notification appliances are tested annually for audibility and visibility; the test must confirm the sound pressure level at the required locations and that all appliances operate.

Battery tests: a load test at the calculated alarm load for the calculated time, or a 30-minute discharge test annually, with replacement when capacity falls below 80 percent of rating.

Supervising station and transmission equipment is tested monthly for signal transmission and quarterly for the central station connection; record all results on the inspection and testing form.

Records of inspection, testing, and maintenance must be retained on the premises for at least one year (or as required by the authority having jurisdiction) and made available for inspection.

A pre-test notification must be given to the owner and the monitoring agency before any test that will transmit signals, to avoid unnecessary emergency response.

Impairment procedures: when a system is out of service for more than 4 hours in a required occupancy, the AHJ, building owner, and monitoring agency must be notified and a fire watch implemented.

The fire alarm control unit (FACU) must be listed for the purpose, have a secondary power supply, and provide the required annunciation of alarm, supervisory, and trouble conditions.

Alarm signals take priority over supervisory and trouble signals; a subsequent alarm on a different zone must be annunciated even if a prior alarm is active.

Trouble signals must be distinctive and must sound within 200 seconds of the fault; supervisory signals must annunciate within 90 seconds.

Digital alarm communicator transmitters (DACTs) must transmit over two separate telephone lines or a single line plus an alternate path; the panel must detect line faults and switch to the alternate.

Central station receivers must be listed and staffed by trained operators; the central station must be able to retransmit signals to the fire department and maintain records of all signals.

Signal transmission time requirements: alarm signals must be transmitted within 90 seconds of activation; the central station must retransmit to the fire department within 90 seconds of receipt.

Proprietary supervising station systems serve multiple buildings under single ownership and must be staffed and equipped to receive and process signals continuously.

Remote supervising station systems must be constantly attended and have a means to notify the fire department; they do not require the same level of redundancy as a central station.

High-rise buildings (generally over 75 ft) require a fire alarm system with voice evacuation, elevator recall, and automatic sprinkler monitoring; the system must be capable of manual and automatic operation.

Assembly occupancies over 300 occupants (or over 50 in some code editions) require a fire alarm system with voice evacuation and emergency lighting interface.

Sprinkler system interfaces: waterflow switches must initiate an alarm, valve tamper switches must initiate a supervisory signal, and flow/tamper devices must be monitored by the FACU.

Elevator recall: smoke detectors in elevator lobbies, machine rooms, and hoistways initiate Phase I recall; a detector in the elevator pit or car initiates Phase II recall.

HVAC shutdown: duct smoke detectors must shut down the air handling unit upon alarm and must be supervised for power and airflow; the shutdown must not disable the fire alarm system.

Door release: magnetic hold-open devices must release upon alarm and must be supervised for power; the release circuit must be monitored by the FACU.

Fire suppression systems (clean agent, kitchen hood, foam) must be interfaced to the FACU to annunciate discharge and trouble; the suppression system must not be disabled by the fire alarm system.

Mass notification systems integrated with the fire alarm must prioritize fire alarm signals and must be listed for the combined use; voice intelligibility must be verified in the occupied space.

The New Mexico Regulation and Licensing Department, Construction Industries Division (CID) administers the Fire Protection Systems Contractor and Journeyman licenses under the Construction Industries Licensing Act (NMSA 1978, Chapter 60).

A Fire Protection Systems Contractor license is required to bid, contract, or install fire alarm systems; a Journeyman Fire Protection Systems license is required for individuals performing the work.

Contractors must maintain a qualifying party who holds the appropriate journeyman or master certification and is actively engaged in the business.

Contractors must carry general liability insurance and workers' compensation coverage as a condition of licensure, and must provide proof to CID upon renewal.

Bids and contracts for fire alarm work must be in writing, include the scope of work, and comply with the Construction Industries Division rules; change orders must be documented.

A contractor may not perform work outside the scope of the license classification; fire alarm work requires the Fire Protection Systems classification, not a general electrical license alone.

License renewal is required periodically (generally every three years) with continuing education requirements; failure to renew results in expiration and requires reinstatement.

Complaints and disciplinary actions are handled by the CID; violations may result in fines, suspension, or revocation, and unlicensed contracting is a misdemeanor under New Mexico law.