DE Fire Alarm cheat sheet

NFPA 72 is the installation, testing, and maintenance standard; it is adopted and enforced through the locally applicable building code and fire code, not as a stand-alone law.

System types per NFPA 72: single-station, multiple-station, household, protected premises (local, auxiliary, remote supervising, proprietary, central station), supervising station, and emergency communications.

Chapter 1 covers scope, purpose, application, equivalency, and the requirement that the authority having jurisdiction (AHJ) approve alternatives that provide equivalent protection.

Approval and acceptance: plans and calculations are submitted for review before installation; final acceptance requires a completed record of completion (Form A) and, where applicable, record of system and inspection/testing/maintenance forms.

Documentation set per NFPA 72 includes record of completion, record of system and inspection, testing and maintenance, and, for software-based systems, a record of software and firmware versions.

Impaired fire protection systems require notification of the AHJ, fire department, and building occupants, plus a fire watch or other mitigation where required by the fire code.

Retroactivity: NFPA 72 applies to new installations and to additions, modifications, and extensions; existing systems are governed by the code edition in effect at installation unless the AHJ requires upgrades.

Code hierarchy: statute, then adopted fire/building code, then referenced standards such as NFPA 72, then manufacturer's published instructions, then approved engineering judgments documented in writing.

Approved means acceptable to the AHJ; listed means equipment included in a list published by an organization acceptable to the AHJ that maintains periodic inspection of production.

Authority having jurisdiction (AHJ) is the organization, office, or individual responsible for enforcing code requirements or approving equipment, materials, installations, or procedures.

Shall indicates a mandatory requirement; should indicates a recommendation or advisory; may indicates permission.

Automatic vs. manual initiating device: automatic responds to a physical stimulus without human action; manual requires human action, e.g., a manual fire alarm box.

Supervisory signal indicates a condition of a system or protected premises requiring action, such as valve closure, low air pressure, or battery failure; it is distinct from alarm and trouble signals.

Trouble signal indicates a fault in a circuit, component, or power supply that compromises system operation; distinct audible and visual characteristics are required for alarm, supervisory, and trouble signals.

Referenced standards commonly invoked: NFPA 70 (NEC), NFPA 13 (sprinklers), NFPA 90A (air handling), NFPA 101 (Life Safety Code), NFPA 110 (emergency power), UL 864 (control units), UL 268 (smoke detectors), UL 521 (heat detectors).

Zone is a defined area or portion of a protected premises; addressable systems identify devices individually, while conventional systems group devices by circuit or zone.

Smoke detection technologies: ionization (responds to small particles, better on flaming fires), photoelectric (light obscuration or scattering, better on smoldering fires), and air-sampling (aspirating) detection.

Spot-type smoke detector spacing on a smooth ceiling is 30 ft (9.1 m) with a maximum listed spacing of 30 ft; use the 0.7 times listed spacing rule for ceiling heights above 10 ft and smooth ceilings.

For solid joist or beam construction, detectors may be spaced at the listed spacing if beams are less than 12 in. deep and spacing between beams exceeds the detector spacing; otherwise, each bay is treated individually.

Heat detector spacing: fixed-temperature and rate-of-rise spot detectors commonly use 25 ft (7.6 m) listed spacing for 10 ft ceilings; reduce spacing by 0.7 times listed spacing for higher ceilings.

Detectors must be at least 4 in. (100 mm) from a wall and, where mounted on a wall, 4 in. to 12 in. below the ceiling; keep detectors at least 3 ft from air supply diffusers and 36 in. from HVAC openings.

Duct smoke detectors are required in air handling systems over 2,000 cfm where the system serves more than one story or more than 15,000 sq ft, per NFPA 90A and locally adopted code.

Manual fire alarm boxes must be located within 5 ft of an exit door, unobstructed, mounted 42 in. to 48 in. above the floor, and spaced so travel distance does not exceed 200 ft (or 5 ft within the exit path).

Alarm verification and drift compensation features must be permitted by the AHJ and documented; verification delays alarm processing and cannot be used where immediate response is required.

Audible signal requirements: public mode must produce at least 15 dBA above the ambient sound level or 5 dBA above ambient where ambient exceeds 105 dBA, measured at 10 ft (3 m) from the appliance.

Sound pressure level at the sleeping area pillow must be at least 75 dBA or 15 dBA above ambient, whichever is greater, for private mode sleeping areas.

Temporal-three pattern (0.5 s on, 0.5 s off, 0.5 s on, 0.5 s off, 0.5 s on, 1.5 s off) is the standard evacuation signal and must be used for fire alarm notification unless an approved voice system is used.

Visible appliances: public mode requires 0.0375 candela per square foot of floor area and a minimum of 15 cd; private mode requires 0.0375 cd/sq ft with a minimum of 15 cd.

Mounting height for visible appliances: 80 in. to 96 in. above the finished floor, measured to the top of the lens, for standard applications.

Visible appliance spacing on a smooth ceiling uses the 0.0375 cd/sq ft rule with listed spacing; higher ceilings require increased candela per the manufacturer's listed spacing tables.

Voice evacuation systems must produce intelligible speech with a sound pressure level at least 15 dBA above ambient and must meet intelligibility criteria (CIS or STI) where required by the AHJ.

Notification appliance circuits must be supervised and must not be shared with initiating device circuits; synchronization of visible appliances is required where multiple appliances are visible from one location.

Class A circuits provide redundant paths and continue to operate during a single open or ground fault; Class B circuits do not provide redundancy and will not operate past a single break.

Class X circuits (NFPA 72) provide the highest integrity and continue operation during a single open, ground fault, or short circuit; used for critical pathways.

Initiating device circuits (IDC), notification appliance circuits (NAC), and signaling line circuits (SLC) each have Class A, B, or X designations; the class is a property of the pathway, not the device.

NAC supervision requires an end-of-line device (resistor or listed module) at the end of the circuit; the control unit must detect open and short conditions and annunciate a trouble signal.

SLC wiring must be installed per the manufacturer's listed instructions; addressable devices must be individually identified and the loop must be supervised for opens, shorts, and ground faults.

Separation requirements: fire alarm circuits must be separated from power-limited circuits by at least 2 in. or by a barrier, and cannot be installed in the same raceway as Class 1 power circuits unless permitted by the NEC.

Survivability: where required by the building code (e.g., high-rise, assembly, or atriums), circuits must be protected by a 2-hour fire-rated pathway or listed circuit integrity cable.

Ground fault detection is required on supervised circuits; the control unit must annunciate a ground fault trouble condition and the fault must be located and corrected.

Primary power: the control unit must be connected to a dedicated, unswitched branch circuit, marked at the disconnect means, and provided with a means of lockout/tagout.

Secondary power must be capable of operating the system for 24 hours (or 60 hours where required by the AHJ) plus 5 minutes of alarm signaling, or 15 minutes for voice evacuation systems.

Battery calculation formula: total standby current (A) x standby hours + alarm current (A) x alarm minutes/60 = ampere-hours required; then add a 20% derating factor for battery aging.

Battery charging: the charger must be capable of restoring the battery to 70% capacity within 4 hours and must provide a charging current per the manufacturer's listing; charge voltage is typically 13.8 V for 12 V batteries.

Battery replacement interval is typically 5 years or per manufacturer's instructions; batteries must be tested annually and replaced when they fail load testing.

Uninterruptible power supplies and generators used as secondary power must be listed for fire alarm use and must be tested under load per NFPA 110 and NFPA 72.

Calculations must account for all devices on the system, including notification appliances, initiating devices, and any auxiliary equipment; the worst-case current draw is used.

Battery calculations must be documented and submitted to the AHJ; the record of completion includes the calculated standby and alarm currents and the battery size selected.

Inspection frequency: initiating devices, notification appliances, and control equipment are inspected and tested annually; some components (e.g., batteries, waterflow switches) have more frequent intervals.

Smoke detectors must be tested annually with a listed aerosol or calibrated test method; heat detectors must be tested annually using a listed heat source or by the manufacturer's recommended method.

Manual fire alarm boxes are tested annually by operating the device; notification appliances are tested annually for audibility and visibility.

Batteries are inspected and tested semiannually (or per manufacturer) and replaced when they fail; the charger must be tested for proper float and charge voltage.

Testing records must be maintained for at least 1 year (or as required by the AHJ) and must include the date, tester, device tested, and results; records of completion and inspection/testing/maintenance are required.

The record of inspection and testing must be kept on the premises and made available to the AHJ upon request; the record of completion is retained for the life of the system.

Testing must be performed by qualified personnel; the AHJ may require certification or licensing of testers, and in Delaware, licensing requirements apply to alarm technicians.

Restoration: after testing, the system must be restored to normal operation, and any impairments must be documented and reported to the AHJ and building occupants.

Design begins with a hazard analysis and a review of the applicable building code and NFPA 101 occupancy requirements to determine whether a system is required and what type.

Smoke detector coverage: 30 ft listed spacing on smooth ceilings; use the 0.7 multiplier for ceilings over 10 ft, and reduce spacing near walls, beams, and obstructions.

Heat detector coverage: 25 ft listed spacing for 10 ft ceilings; use the 0.7 multiplier for higher ceilings and follow the manufacturer's listed spacing for specific models.

Manual pull station coverage: within 5 ft of exit doors and spaced so that travel distance to the nearest station does not exceed 200 ft.

Notification appliance coverage: audible appliances must be spaced to achieve the required dBA throughout the protected area; visible appliances use the 0.0375 cd/sq ft rule and listed spacing.

Detectors must be located at least 3 ft from HVAC supply diffusers and 36 in. from air handling openings to avoid dilution of smoke.

Elevator lobbies, stairwells, and exit access corridors require detection and notification per the building code and NFPA 101; smoke detectors in elevator lobbies may be used for elevator recall.

Design documentation must include shop drawings, calculations, and a sequence of operations; the AHJ reviews and approves before installation.

Delaware adopts the International Fire Code (IFC) and NFPA 1 as the state fire prevention code, with local amendments; NFPA 72 is referenced for fire alarm installation and testing.

The Delaware State Fire Prevention Commission and the Office of the State Fire Marshal administer and enforce the state fire prevention regulations.

Fire alarm contractors and technicians must be licensed by the Delaware State Fire Prevention Commission; licensing requires examination and continuing education.

Fire alarm system plans and specifications must be submitted to the Office of the State Fire Marshal for review and approval before installation.

Delaware requires compliance with NFPA 72 for installation, inspection, testing, and maintenance; records must be maintained and made available to the State Fire Marshal.

Local jurisdictions may have additional requirements; the AHJ for a given project may be the State Fire Marshal or a local fire official, depending on the jurisdiction.

Fire alarm system impairments must be reported to the State Fire Marshal and the local fire department, and a fire watch may be required during impairment.

Licensing and certification requirements include periodic renewal and continuing education; technicians must carry proof of licensure and comply with state and local codes.