Key numbers (NFPA 72 · NEC · OSHA)
Quick reference
The values asked most often, with their section in the exam editions (NFPA 72-2022, NEC 2020, current OSHA). Where the exact subsection could not be confirmed, the general section is cited. The 2022 edition renumbered parts of Chapters 17 and 18, so if your book is a different edition the numbers may not match.
Power and signals (NFPA 72 Ch. 10 and 12)
| Topic | Value | Section |
|---|---|---|
| Secondary power (batteries) | 24 h standby + 5 min alarm; voice systems (EVACS): 24 h + 15 min | §10.6.7.2 |
| Battery capacity margin | A safety margin is required in the calculation; industry sources report 25% in the 2022 edition (previously 20%) | §10.6.7 / §7.2.1 |
| Battery marking | Month and year of manufacture | §10.6.10.1 |
| Control unit branch circuit | Dedicated, red-marked disconnect, accessible only to authorized personnel, location identified at the control unit | §10.6.5 |
| Control unit display height | Highest control ≤ 6 ft; lowest ≥ 15 in. above the floor | §10.4.4 |
| Smoke detection at the control unit | Where the area is not continuously occupied | §10.4.5 |
| Notification start | ≤ 10 s after an initiating device activates | §10.11.1 |
| Trouble annunciation | ≤ 200 s after the fault | §12.6.1 |
| Silenced trouble | Resounds every ≤ 24 h until corrected | §10.15 |
| Impairment | Notify the owner; if the system is out of service more than 8 h, the service provider notifies the AHJ. (The “4 hours” with a fire watch comes from NFPA 101/IFC.) | §10.21 |
| Uncorrected deficiency | Reported to the owner in writing within 24 h | §14.2.2 |
NEC 2020 (Article 760 and Chapter 9)
| Topic | Value | Section |
|---|---|---|
| Branch circuit (NPLFA and PLFA) | No GFCI or AFCI; red-identified disconnect marked “FIRE ALARM CIRCUIT”; accessible only to qualified personnel; location shown at the control unit | 760.41(B) · 760.121(B) |
| NPLFA overcurrent protection | 18 AWG: 7 A · 16 AWG: 10 A | 760.43 |
| PLFA separation from light and power | 2 in. (50 mm) where neither is in a raceway | 760.136(G) |
| PLFA cables | FPLP plenum · FPLR riser · FPL general; a higher rating may substitute for a lower one | 760.154 · Table 760.154(A) |
| CI cable on steel | Supported every 24 in. | 760.24(B) |
| Abandoned cables | Remove the accessible portion (unless tagged for future use) | 760.25 |
| Support | From the building structure; not from ceiling grid or its support wires | 760.24(A) · 300.11 |
| Conduit fill | 1 conductor 53% · 2 conductors 31% · over 2: 40% | Ch. 9, Table 1 |
Initiating devices (NFPA 72 Ch. 17)
| Topic | Value | Section |
|---|---|---|
| Smoke detector on a sidewall | Between the ceiling and 12 in. below it (to the top of the detector) | §17.7.4.2 |
| Smoke spacing, smooth ceiling | 30 ft nominal; every point within 0.7 × S (21 ft) of a detector | §17.7.4.2.3.1 |
| Smoke detector environment | 32–100 °F, humidity below 93%, air velocity below 300 ft/min (unless listed otherwise) | §17.7.1 |
| Detectors during construction | Not installed until cleanup is complete unless the AHJ requires it; if installed, protected | §17.7.2 |
| Spot heat detector | On the ceiling ≥ 4 in. from the wall, or on the wall 4–12 in. below the ceiling | §17.6.3.1.3 |
| Heat detector rating | At least 20 °F above the maximum expected ceiling temperature | §17.6.2 |
| Nonrestorable heat detectors | At 15 years: replace, or lab-test 2 of every 100 | Table 14.4.3.2 |
| Manual fire alarm box | Operable part 42–48 in. above the floor; ≤ 5 ft from each exit; travel ≤ 200 ft | §17.15 |
| Waterflow | Alarm ≤ 90 s after flow equal to one sprinkler | §17.13.2 |
| Valve supervisory switch | Signal within 2 revolutions of the handwheel or 1/5 of the travel | §17.17.1 |
Notification (NFPA 72 Ch. 18)
| Topic | Value | Section |
|---|---|---|
| Public mode | 15 dB above average ambient or 5 dB above the maximum lasting ≥ 60 s (whichever is greater), 5 ft above the floor | §18.4.4.1 |
| Private mode | 10 dB above average ambient or 5 dB above the 60 s maximum | §18.4.5.1 |
| Sleeping areas | Greatest of 15 dB / 5 dB / 75 dBA at the pillow; 520 Hz low-frequency signal | §18.4.6 |
| Maximum | 110 dBA at the minimum hearing distance; average ambient above 105 dBA requires visible appliances | §18.4.1 |
| Wall-mounted audible | Top ≥ 90 in. above the floor and ≥ 6 in. below the ceiling | §18.4.9.1 |
| Wall-mounted visible | Entire lens between 80 and 96 in. above the floor | §18.5.5.1 |
| Flash rate | 1–2 Hz; clear or nominal white; ≤ 1000 cd | §18.5.3 |
| Candela table, wall-mounted | 20×20 → 15 cd · 28×28 → 30 · 30×30 → 34 · 40×40 → 60 · 45×45 → 75 · 50×50 → 94 | Table 18.5.5.7.1(a) |
| Corridors (≤ 20 ft wide) | ≥ 15 cd; ≤ 15 ft from each end; ≤ 100 ft apart | §18.5.5.8 |
| Sleeping rooms | 177 cd if the lens is less than 24 in. from the ceiling, otherwise 110 cd; within 16 ft of the pillow | §18.5.5.10 |
Circuits, control functions and supervision (Ch. 12, 21, 23, 26)
| Topic | Value | Section |
|---|---|---|
| Class A / X outgoing and return | Routed separately; allowed together for ≤ 10 ft where entering a device, for a single drop, or in areas ≤ 1000 ft². (1 ft vertical / 4 ft horizontal is only an annex recommendation.) | §12.3.8.1 |
| Pathway survivability | Levels 0 to 4 | §12.4 |
| Emergency control relay | Within 3 ft of the controlled component | §21.2.4 |
| Elevator power shutdown | Heat detector within 2 ft of each sprinkler, rated lower than the sprinkler | §21.4 |
| Positive alarm sequence | Acknowledge within 15 s; investigate up to 180 s | §23.8.1.2.1.1 |
| Alarm verification | Maximum delay 60 s | §23.8.5.4 |
| DACT | Two means of transmission; each channel tested at least every 6 h; call attempt ≤ 90 s | §26.6.4 |
| Central station | Retransmit alarms immediately; runner within 2 h | §26.2 · §26.3 |
Inspection, testing and records (Ch. 14 and 7)
| Topic | Value | Section |
|---|---|---|
| Smoke detector sensitivity | Within 1 year of installation, then every other year; may be extended up to 5 years if stable | §14.4.4.3 |
| Software change | 100% of affected functions + 10% of unaffected initiating devices (max. 50) | §14.4.2.4 |
| ITM records | Until the next test and for 1 year after | §14.6.2.1 |
| Permanent records | For the life of the system | §14.6.1.3 |
| Stray voltage on conductors | ≤ 1 V | Table 14.4.3.2 |
| System documents | In a documentation cabinet (not inside the control unit) | §7.7.2 |
| Forms | Record of completion: Figure 7.8.2(a) · Inspection and testing: Figure 7.8.2(g) | §7.8.2 |
There is no Table 14.4.5 in the 2022 edition. Test frequencies are in the Periodic Frequency column of Table 14.4.3.2. A lot of older study material still cites a separate “Table 14.4.5, Testing Frequencies”.
| Component | Visual inspection (Table 14.3.1) | Test (Table 14.4.3.2) |
|---|---|---|
| Monitored control unit (fuses, LEDs, primary power) | Annual (trouble signals: semiannual) | Annual |
| Unmonitored control unit | Weekly | Annual |
| Manual boxes, smoke, heat and duct detectors | Semiannual | Annual |
| Flame detectors | Quarterly | Semiannual |
| Waterflow devices | Semiannual (was quarterly) | Semiannual |
| Control valve supervisory (tamper) switch | Semiannual | Semiannual |
| Other supervisory: air pressure, temperature, water level | Semiannual | Annual |
| Notification appliances | Semiannual | Annual |
| VRLA batteries | Semiannual (includes the date of manufacture) | Semiannual (temperature, charger, voltage, ohmic test); replace or load-test every 3 years |
| Secondary power | — | Annual (5 min in alarm; 15 min for voice systems) |
| Supervising station transmitters | Annual | Annual |
| Household smoke alarms | — | Replace at 10 years |
Read each frequency from the Periodic Frequency column of Table 14.3.1 (inspection) or Table 14.4.3.2 (testing), and count the interval from the date of the last inspection or test: semiannual items come due about 6 months later and annual items about 12 months later.
Safety (OSHA and first aid — these books are not allowed in the test center)
| Topic | Value | Section |
|---|---|---|
| Ladder to an upper landing | Side rails ≥ 3 ft above the landing | 1926.1053(b)(1) |
| Ladder angle | Base 1/4 of the working length from the wall (4:1) | 1926.1053(b)(5)(i) |
| Stepladder | Do not use the top or top step as a step | 1926.1053(b)(13) |
| Near energized equipment | Ladders with nonconductive side rails | 1926.1053(b)(12) |
| Fall protection | Construction 6 ft · general industry 4 ft · scaffolds 10 ft | 1926.501 · 1910.28 · 1926.451(g) |
| Guardrail | Top rail 42 in. ± 3 in.; withstands 200 lb | 1926.502(b) |
| Personal fall arrest | Free fall ≤ 6 ft; anchorage 5,000 lb per person | 1926.502(d) |
| Scaffolds | Support 4 times the intended load | 1926.451(a)(1) |
| Noise | Hearing conservation program from 85 dBA (8-h TWA); limit 90 dBA | 1910.95 |
| Trenches | Protective system from 5 ft deep | 1926.652 |
| Construction sites | GFCI on temporary receptacles (or an assured equipment grounding conductor program) | 1926.404(b)(1) |
| Safety data sheets (SDS) | 16 sections | 1910.1200(g) |
| Adult CPR | 100–120 compressions/min; at least 2 in. deep; 30 compressions : 2 breaths | Red Cross |
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More NICET Fire Alarm study guides
- 8-week study plan
- Fundamentals and Definitions
- Initiating Devices
- Notification Appliances
- Circuits, Systems, and Control Functions
- NEC 2020 (NFPA 70): Article 760 and Wiring Methods
- Basic Electricity and Calculations
- Inspection, Testing and Maintenance
- Troubleshooting, Repair and Device Replacement
- Job Site Safety: OSHA 1910/1926 and First Aid
- Technical Documents, Drawings, and Submittals
- Community-Reported Topics
- Level I tabbing guide for your printed code books
- Strategy with printed code books
- Key numbers (NFPA 72 · NEC · OSHA)
- Formulas and conversions
- Fire alarm glossary for the NICET exams