Fire Alarm Systems practice questions

Correct: C — None of the listed NPLFA types

Per 760.53(B)(1), Types NPLFP, NPLFR, and NPLF shall not be installed exposed in ducts specifically fabricated for environmental air. Plenum-rated NPLFP is for other air-handling spaces, not fabricated ducts themselves, which is a common point of confusion.

Correct: D — Type FPLP, FPLR, or FPL

760.179(C) requires marking as Type FPLP, FPLR, or FPL. Type CL2/CL3 are Class 2/3 cable markings, MC/AC are metal-clad and armored cable, and THHN/THWN are building-wire insulation types — none apply to line-type fire detector cable.

Correct: C — 760.53(A)(1)

760.53(A)(1) governs exposed NPLFA cable and sets the 450 mm (18 in.) fastening interval within 7 ft of the floor; 760.53(A)(2) instead addresses cable passing through a floor or wall, and 760.53(A)(3) covers hoistway installations — neither has a fastening-interval rule.

Correct: D — Type NPLFP

760.176(C) requires Type NPLFP for use in ducts and other spaces used for environmental air, with listed fire-resistant and low smoke-producing characteristics. Type NPLFR is for vertical risers, not air spaces, and plain Type NPLF is explicitly excluded from duct and plenum use per 760.176(E). Running any NPLFA cable in conduit does not substitute for the required plenum listing.

Correct: C — 7 amperes

760.43 sets a hard cap of 7 amperes of overcurrent protection for 18 AWG NPLFA conductors. The 10-ampere figure is the cap for 16 AWG conductors, not 18 AWG — mixing up the two gauge/cap pairs is the most common error.

Correct: A — The circuit is protected by a GFCI breaker at the panel

760.121(B)(2) prohibits supplying the fire alarm branch circuit through GFCI or AFCI protection, since a nuisance trip could disable fire alarm power. The dedicated-load requirement, the red 'FIRE ALARM CIRCUIT' marking, and securing the disconnect in the on position are all required or permitted, not violations.

Correct: D — At least 50 mm (2 in.)

760.136(H) sets the default separation at 50 mm (2 in.) between PLFA conductors and electric light, power, Class 1, non-power-limited fire alarm, or medium-power network-powered broadband circuit conductors, unless one of the listed exceptions applies.

Correct: D — Cable routing assemblies follow 800.110(C) and 800.113; communications raceways follow 800.113 and the ENT rules in 362.24–362.56

760.3(K) points cable routing assemblies to 800.110(C) and 800.113, while 760.3(L) points communications raceways to 800.113 plus the ENT installation rules in 362.24–362.56 — the two installation rule sets are not interchangeable, and both pathway types require 800.182 listing.

Correct: B — It must comply with the general corrosive, damp, and wet location provisions that apply to any wiring method

760.3(C) requires fire alarm circuits and equipment in corrosive, damp, or wet locations to comply with the same general provisions that govern every wiring method there — there's no fire-alarm-specific exception, and a fire alarm listing alone doesn't substitute for location-based protection.

Correct: C — The conductor size and the temperature rating, since it exceeds 60°C (140°F)

760.176(G) requires the jacket to always show conductor size, and to show the temperature rating whenever it exceeds 60°C (140°F). At 75°C, both markings are required. Treating 90°C as the trigger point, exempting conductor size, or exempting the cable entirely all misstate the rule.

Correct: D — Only if the raceway installation is specifically listed and marked as part of an electrical circuit protective fire-resistive cable system

Per 760.176(F)(1), CI cable only keeps its listed fire-resistive rating in free air; it may be installed in a raceway only where specifically listed and marked as part of an electrical circuit protective fire-resistive cable system under 760.176(F)(2). Raceway material and power-limited rating are not the deciding factors.

Correct: C — 18 AWG or larger solid or stranded copper

760.176(A) requires NPLFA conductors to be 18 AWG or larger solid or stranded copper. A 16 AWG minimum is not the stated threshold, aluminum is not permitted, and solid copper only (excluding stranded) is too restrictive.

Correct: B — 300.17, the same conductor-counting method used for general raceway fill

760.51(A) states the number of conductors is determined per 300.17. 310.15(C)(1) governs ampacity adjustment, not conductor count, and 392.22 applies to cable trays, not raceways.

Correct: C — No, only copper conductors are permitted for fire alarm systems

760.49(A) states only copper conductors are permitted for fire alarm systems — there is no aluminum allowance, upsized or otherwise, and the raceway requirement applies to 18/16 AWG copper conductors, not to permitting aluminum.

Correct: B — The secondary has only a 2-wire (single-voltage) output and the protection meets 450.3 and the voltage-ratio limit

760.45 permits primary-side overcurrent protection to serve as protection for the secondary only when the secondary is a 2-wire (single-voltage) configuration, sized per 450.3 and the secondary-to-primary voltage ratio. A 3-wire or multi-tap secondary is explicitly excluded from this allowance, and there is no exception based on conductor length or general fire-alarm listing.

Correct: B — GFCI or AFCI protection

760.41(B) explicitly bars supplying the fire alarm branch circuit through GFCI or AFCI protection, since a nuisance trip could disable the fire alarm system. A permanently identified standard breaker or fused disconnect is the expected setup, not the prohibited one.

Correct: A — 760.130(B)(1)

760.130(B)(1) sets the securing interval (not more than 18 in.) and physical-damage protection for PLFA cable exposed on sidewalls or fished in concealed spaces within 7 ft of the floor. 760.130(B)(2) instead governs cable passing through a floor or wall, and 760.136(A) covers separation from other circuit conductors, not support/protection.

Correct: C — 760.154(A)

760.154(A) hosts Table 760.154(A), Cable Substitutions, and Figure 760.154(A) illustrating which PLFA/fire alarm cable types may substitute for others. 760.154 hosts the separate table listing where each PLFA cable type is permitted to be used in buildings, not the substitution hierarchy; 760.176 covers listing and marking requirements for NPLFA cables, not substitutions.

Correct: D — 760.130(A)

760.130(A) is titled NPLFA Wiring Methods and Materials and specifically governs NPLFA conductors on the load side. 760.130(B) instead covers PLFA conductors and cables, and 760.127 governs the supply side rather than the load side.

Correct: C — 760.136(A)

760.136(A) is the general prohibition on placing PLFA cables in the same cable, cable tray, enclosure, or raceway as electric light, power, Class 1, NPLFA, or medium-power network-powered broadband conductors unless an exception in 760.136(B)-(G) applies. 760.139(A) instead governs mixing multiple PLFA circuits with each other, not with power conductors, so it doesn't fit this scenario.

Correct: C — A bushing, per 300.15(C)

Per 760.3(J), a bushing is required where cables emerge from a raceway used for mechanical support or protection, in accordance with 300.15(C). A junction box isn't required just because a raceway ends, and fire alarm wiring has no blanket exemption from this rule. A grounding bushing under 250.97 addresses bonding at service equipment, not this scenario.

Correct: B — 760.25

760.25 directly requires removal of the accessible portion of abandoned fire alarm cables. 760.24 governs mechanical execution of work (support and installation of cables still in use), not abandonment, and 760.30 covers circuit identification/labeling of active circuits, not abandoned ones.

Correct: D — 760.24(B)

760.24(B) is the CI cable subsection that sets the 24 in. (610 mm) general support spacing (tightening to 18 in. within 7 ft of the floor). 760.24(A) only states the general mechanical-execution requirement without a spacing figure, and 760.3(H) addresses vertical support of fire-resistive cables in shafts, not routine support spacing.

Correct: C — 760.30

760.30 specifically requires fire alarm circuits to be identified at terminal and junction locations to prevent unintentional signals during testing/servicing of other systems. 760.32 governs circuits that extend between buildings, and 760.35 sets general NPLFA/PLFA circuit requirements — neither addresses labeling at junctions.

Correct: C — Article 805, Parts II, III, and IV, plus Article 300, Part I

Per 760.32, both NPLFA and PLFA circuits that extend beyond one building and run outdoors must meet Article 805, Parts II, III, and IV, and Article 300, Part I. Article 725 doesn't govern fire alarm circuits, being power-limited doesn't exempt the circuit from this rule, and Article 800 covers communications circuits, not the article referenced by 760.32.

Correct: C — 760.3(B)

760.3(B) specifically permits power-limited fire alarm cable listed to Table 760.154 to be installed in plenums used for environmental air per 722.135. 760.3(A) addresses spread of fire/products of combustion generally, not the plenum cable permission itself, and 760.3(G) covers raceways exposed to different temperatures, not plenum cabling.

Correct: C — An ungrounded signal conductor, if installed per 760.154(A)

760.3(N) creates a specific exception: in FPLP, FPLR, FPL, and substitute cables, green insulation may be an ungrounded signal conductor when installed per 760.154(A). Green is otherwise reserved for equipment grounding conductors per 250.119, which is why the other options describe grounding-related uses rather than the actual exception.