CA Fire Alarm flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

California Fire Code citation

The California Fire Code is CCR Title 24, Part 9. It adopts the International Fire Code with state amendments, and Chapter 9 regulates fire alarm and detection system installation and maintenance.

NFPA 72 scope

NFPA 72 is the National Fire Alarm and Signaling Code. It covers design, installation, commissioning, inspection, testing, and maintenance of detection and notification systems, and is adopted by reference in California.

NEC Article 760

NEC Article 760 governs fire alarm system wiring, including power-limited and non-power-limited fire alarm circuits, conductor listing, and separation requirements from other circuit classes.

AHJ authority

The authority having jurisdiction enforces the adopted code and approves plans, equipment, and acceptance tests. Its written policies control interpretations where the code permits alternatives or exceptions.

Photoelectric detector principle

A photoelectric smoke detector uses a light source and sensor in a chamber. Smoke entering the chamber scatters light onto the sensor, producing an alarm signal, and it responds best to visible smoldering smoke.

Ionization detector principle

An ionization detector uses a small radioactive source to ionize air in a chamber. Smoke particles attach to ions and reduce current flow, triggering alarm, and it responds well to small flaming-fire particles.

Rate-of-rise heat detector

A rate-of-rise heat detector alarms when temperature increases faster than a set rate, typically about 15 degrees Fahrenheit per minute. It responds quickly to rapidly growing fires.

Smoke detector spacing

On a smooth ceiling, spot-type smoke detectors are spaced at 30 feet, with the first detector within 15 feet of any wall. Higher ceilings permit increased spacing using listed correction factors.

Duct smoke detector threshold

Duct smoke detectors are required for air-handling systems of 2,000 cubic feet per minute or greater. They initiate smoke control functions and equipment shutdown and do not replace open-area detection.

Public mode audibility

In public mode, audible notification must exceed ambient sound by 15 dBA, or by 5 dBA where ambient exceeds 105 dBA, measured at 5 feet above the floor in the occupied area.

Sleeping area audibility

In sleeping areas, the alarm must produce 75 dBA at the pillow or 15 dBA above ambient, whichever is greater. The measurement is taken at the head of the bed.

Visible signal flash rate

Visible notification appliances flash at 1 to 2 Hz with a pulse duration of at least 0.2 second. Appliances in the same area must be synchronized to avoid increased seizure risk.

Voice intelligibility requirement

Voice evacuation messages must be understandable in the occupied space. Intelligibility is verified by measurement or a listed design method, and messages must be prioritized and clearly worded.

Class A versus Class B

Class A circuits continue to operate after a single open or ground fault. Class B circuits annunciate the fault but lose the portion of the circuit beyond the fault point.

Addressable signaling line circuit

An addressable signaling line circuit carries data and power to individually identified devices. It must be installed within the manufacturer's listed limits for device count, distance, and loading.

Supervising station signal paths

The connection to a supervising station must be arranged so a single fault does not disable both alarm and supervisory signals. Two independent paths or a listed supervised single path are used.

Trouble signal characteristics

Trouble signals must be distinct from alarm and supervisory signals by audible and visible means. They must resound and may be silenced only by authorized personnel.

Dedicated branch circuit

Fire alarm primary power must be a dedicated branch circuit, marked and protected against accidental disconnection, and connected ahead of the main disconnect so building power shutdown does not disable it.

Secondary power duration

Where 24 hours of standby is required, secondary power must support the system for 24 hours of standby plus 5 minutes of alarm operation, using battery or generator capacity.

Battery calculation formula

Battery capacity equals standby load current times standby hours plus alarm load current times alarm hours, multiplied by a 1.2 aging and temperature factor, expressed in ampere-hours.

Battery charger requirement

The charger must restore the battery to at least 85 percent capacity within 24 hours after discharge. Charging voltage and current must remain within the battery manufacturer's published limits.

End-of-line resistor function

An end-of-line resistor terminates a supervised initiating device circuit. It allows the control unit to detect open circuits and grounds by monitoring current flow through the circuit.

Power-limited circuit separation

Power-limited fire alarm circuits must be separated from non-power-limited circuits by at least 2 inches or a listed barrier, and cannot share a raceway without a barrier.

Plenum cable requirement

Fire alarm cable installed in environmental air spaces must be listed for plenum use. Riser-rated cable is required in vertical shafts, and both must be listed for fire alarm service.

Ground fault supervision

A ground fault on a supervised fire alarm circuit must annunciate as a trouble at the control unit. A single ground on a Class B circuit does not prevent alarm operation.

Annual smoke detector test

Smoke detectors require annual functional testing using listed test smoke or a listed test method. Detectors failing sensitivity limits must be cleaned or replaced and retested.

Waterflow switch test

Waterflow switches are tested by opening the inspector's test valve. The switch must operate within the time allowed by the standard and produce an alarm at the control unit.

Tamper switch testing

Tamper switches on control valves must be tested in both the open and closed positions. Each position must produce a distinct supervisory signal at the fire alarm control unit.

Impairment program

When a system is impaired, the AHJ and occupants must be notified, a fire watch provided where required, and the system restored and verified before returning to normal service.

Plan submittal contents

Submittals include floor plans with device locations, riser diagrams, sequence of operations, battery and voltage drop calculations, and manufacturer's data sheets for all listed equipment.

Voltage drop calculation

Voltage drop calculations verify that at the lowest supply voltage, the appliance at the end of the circuit still receives its listed minimum operating voltage under alarm conditions.

Acceptance test purpose

Acceptance testing demonstrates that the installed system operates as designed before it is placed in service. The AHJ witnesses the test and the contractor certifies the results.