Notification Appliances (NFPA 72-2022 Ch. 18)
NFPA 72-2022 Ch. 18 · NFPA 72-2022 Table 14.4.3.2 · NFPA 72-2022 Ch. 12 · Bukowski, Fire Alarm Signaling Systems · Outline tasks 1.1.1, 1.2.1, 1.3.1, 1.2.2
What NICET expects at Level I
A Level I technician mounts and terminates notification appliances (task 1.1.1), tests them (1.2.1), replaces them when they fail (1.2.2), and must be able to read drawings and data sheets (1.3.1), always under supervision. On this topic the exam mostly asks about mounting heights, candela selection from the room spacing tables, audibility levels (dB above ambient), signal patterns (Temporal-3 and Temporal-4), synchronization, the corridor and sleeping room rules, and good NAC wiring practice (polarity, end-of-line resistor, no T-taps). Almost everything is in Chapter 18 of NFPA 72-2022; testing is in Table 14.4.3.2.
General requirements (§18.3)
- Listing: every appliance must be listed for the purpose for which it is used (§18.3.1). Appliances for special environments (outdoors, temperature extremes, humidity, dust, hazardous locations, or subject to tampering) must be listed for that application (§18.3.3.1).
- Nameplate: shows the electrical requirements and the rated audible and/or visual performance, or refers to the installation documents (§18.3.2).
- Markings: an appliance used for signals other than fire must not carry the word FIRE. In 2022, existing appliances may have their marking modified in the field per the manufacturer, or with a permanent sign stating that the appliance is multipurpose (§18.3.3).
- Mechanical protection: where subject to damage, protect it; guards or covers must be listed for use with that appliance (§18.3.4).
- Mounting: supported independently of the circuit conductors and installed per the manufacturer's published instructions (§18.3.5).
- Connections and NACs: terminals must allow the connections to be monitored for integrity (§18.3.6). The NAC complies with Chapter 12 (§18.3.7, new in 2022). Annex A.18.3.7.1 reminds you that regulated 24 VDC appliances must operate from 16 to 33 VDC and that the maximum listed current is used for load calculations.
Audible appliances (§18.4)
| Application | Requirement | Where measured | Ref. |
|---|---|---|---|
| Public mode | 15 dB above the average ambient or 5 dB above the maximum lasting 60 s or more (whichever is greater) | 5 ft (1.5 m) above the floor, dBA | §18.4.4.1 |
| Private mode | 10 dB above the average or 5 dB above the 60-s maximum (whichever is greater) | 5 ft above the floor, dBA | §18.4.5.1 |
| Sleeping areas | 15 dB / 5 dB / 75 dBA (whichever is greater) and a 520 Hz ±10 percent low-frequency signal from listed equipment | At pillow level, with doors or curtains closed | §18.4.6 |
| Maximum | 110 dBA total (ambient plus all audible appliances) | At the minimum hearing distance | §18.4.1.2 |
| Ambient over 105 dBA | Visual appliances are required | — | §18.4.1.1 |
| Wall mounting (audible only) | Top not less than 90 in. above the floor and not less than 6 in. below the ceiling | — | §18.4.9.1 |
| Combination audible/visual | Located by the visual rules (§18.5.5) | — | §18.4.9.3 |
Other points: noise lasting 60 s or more counts toward the maximum (§18.4.1.3). Elevators and, with AHJ approval, restrooms may use the private mode criteria (§18.4.4.3–18.4.4.4). If the system shuts off music or machinery, the signal must be 15 dB above the reduced ambient and visual appliances are added (§18.4.4.5). Narrow band tone signaling (§18.4.7): 10 dB above the masked threshold per octave band or 13 dB per one-third octave band. Exit marking audible appliances (§18.4.8): at the entrance to exits and areas of refuge. The designer documents the design sound levels for acceptance testing (§18.4.1.5).
Signal patterns
- Evacuation: Temporal-3 per ANSI/ASA S3.41 (0.5 s on / 0.5 s off three times, then 1.5 s off; 4-s cycle), synchronized within the notification zone (§18.4.2).
- Duration (2022 change): the signal repeats until authorized or emergency personnel manually silence or reset the system. Automatic silencing is permitted only with AHJ approval based on an emergency response plan, and never sooner than 180 s (§18.4.2.2–18.4.2.3).
- Carbon monoxide (CO): Temporal-4, four cycles of 100 ms on / 100 ms off followed by 5 s off; after 4 minutes the off period may become 60 s (§18.4.3).
Visual appliances (§18.5)
- Flash rate between 1 and 2 Hz; clear or nominal white light; maximum 1000 cd effective (§18.5.3). Light distribution per UL 1638 (§18.5.4).
- Wall: the entire lens between 80 and 96 in. above the floor (§18.5.5.1). If the ceiling is too low, mount within 6 in. of the ceiling and reduce the covered room size by twice the difference from 80 in.
- Ceiling (new in 2022): an appliance listed for ceiling mounting goes not less than 80 in. above the floor or at the actual ceiling height, whichever is less (§18.5.5.5). Obstructions must be considered (§18.5.5.6).
- Synchronization: more than two appliances (or groups) in the same field of view must flash in synchronization, even if separate systems or circuits feed them (§18.5.5.7.2).
| Room (ft) | Wall, 1 appliance (cd) – Table 18.5.5.7.1(a) | Ceiling, ceiling height 10 / 20 / 30 ft (cd) – Table 18.5.5.7.1(b) |
|---|---|---|
| 20 × 20 | 15 | 15 / 30 / 55 |
| 28 × 28 | 30 | — |
| 30 × 30 | 34 | 30 / 45 / 75 |
| 40 × 40 | 60 | 60 (10 ft) |
| 45 × 45 | 75 | — |
| 50 × 50 | 94 | 95 (30 ft) |
| 54 × 54 | 110 | — |
| 60 × 60 | 135 | — |
| 68 × 68 | 177 | 177 (30 ft) |
| 70 × 70 | 184 | 185 (30 ft) |
Non-square rooms or off-center wall appliance: use the distance to the farthest wall or twice the distance to the farthest adjacent wall, whichever is greater. Off-center ceiling appliance: double the distance to the farthest wall. An irregular room is enclosed in a square or divided into squares. If the ceiling is higher than 30 ft, suspend the appliance at or below 30 ft or use wall mounting (§18.5.5.7).
Corridors (§18.5.5.8) and sleeping rooms (§18.5.5.10)
- Corridor 20 ft wide or less: appliances of at least 15 cd, not more than 15 ft from each end and not more than 100 ft apart. A fire door, elevation change, or other obstruction creates a separate corridor. More than two in view must be synchronized. They may be on the ceiling, a side wall, or the end wall. If the corridor is wider than 20 ft, use the room rules.
- Sleeping room: if the top of the lens is 24 in. or more below the ceiling, 110 cd is enough. If it is less than 24 in., 177 cd is required (because of the smoke layer). In rooms larger than 16 ft, the appliance must be within 16 ft of the pillow. The performance-based method (§18.5.5.9) does not apply to sleeping rooms.
Other appliances
Textual and graphical visual appliances (message signs, §18.9); textual audible appliances (speakers); tactile appliances, such as bed shakers, per UL 1971 (§18.10). The Standard Emergency Service Interface requires annunciators and controls for fire fighters to be designed in coordination with the organizations that use them.
NAC installation and termination
- Respect the marked polarity. DC appliances are polarized: the panel supervises with reversed polarity and reverses it in alarm.
- The end-of-line (EOL) resistor goes at the last appliance of a Class B NAC. Do not make T-taps, because the branch would not be supervised.
- Cut the conductor at the terminals (in and out) so that a removed wire produces a trouble signal, per the manufacturer.
- Set every multi-candela appliance to the value on the approved drawings and record the setting.
- Use appliances and sync modules that share the same protocol. Calculate voltage drop with the maximum listed current, because low voltage causes loss of sync or weak output.
Testing (link to Ch. 14)
Per Table 14.4.3.2 (alarm notification appliances row):
- Audible: at acceptance and reacceptance, measure the sound level with an ANSI/ASA S1.4 Type 2 meter set to FAST. At the annual test, verify that they operate.
- Visual: at acceptance, verify locations against the drawings, that the marked candela matches the approved drawings, and that they flash. At the annual test, verify that each appliance flashes.
- Exit marking: annual test per the manufacturer.
- Every replaced appliance is tested (reacceptance, §14.4.2).
Common traps:
- The 90 in. / 6 in. rule is for audible-only appliances. A horn/strobe follows the 80–96 in. visual rule.
- 30 cd covers 28 × 28 ft, not 30 × 30 ft, which needs 34 cd.
- The 75 dBA in sleeping rooms is a minimum measured at the pillow, not 5 ft above the floor.
- The maximum is 110 dBA. If the ambient exceeds 105 dBA, visual appliances are required.
- Calculate both criteria (15 dB above the average and 5 dB above the 60-s maximum) and use the greater.
- A strobe built into a ceiling-mounted smoke detector in a sleeping room needs 177 cd.
- In 2022 the evacuation signal is no longer just "180 s minimum": it sounds until manually silenced, unless the AHJ approves automatic silencing.
- Numbering: older material cites Table 18.5.5.4.1 (2013/2016 editions) or 18.5.5.5.1 (2019); in 2022 it is 18.5.5.7.1. With the new §18.4.3 for CO, the 2022 numbers are: public mode 18.4.4, private 18.4.5, sleeping 18.4.6, exit marking 18.4.8, and location 18.4.9.
Finding it fast in the printed code book
- Everything numbered 18.x is in Chapter 18. Put permanent tabs on §18.4 (audible), §18.5 (visual), and the two room spacing tables, Table 18.5.5.7.1(a) and (b), so you can flip straight to the candela values.
- Useful index entries at the back of NFPA 72: "Notification appliances", "Visual notification appliances", "Audible notification appliances", "Sleeping areas", "Corridors", "Temporal pattern", "Synchronization".
- Highlight the key numbers on the page: 90 in. / 6 in. (audible mounting), 80–96 in. (visual mounting), 110 dBA and 105 dBA, 15 dB / 10 dB / 5 dB, 75 dBA and 520 Hz, 15 ft / 100 ft (corridors), 24 in. / 110 cd / 177 cd (sleeping rooms).
- For testing, flip to Table 14.4.3.2 and find the "Alarm notification appliances" row; tab that page too.
- An asterisk (*) next to a section means there is explanatory material in Annex A (for example, A.18.3.7.1 on NAC voltage). It helps you understand the rule, but it is not mandatory.
Tip: on candela questions, first determine the room size (the square that encloses the room, or the farthest-wall / twice-the-adjacent-wall rule), then find the row in the table and pick the nearest value or setting that is equal or higher. On audibility questions, write down both calculations and keep the greater one.
What to tab in your books
| Section | Why |
|---|---|
| NFPA 72-2022 §18.3 | General: listing, nameplate, mechanical protection (§18.3.4), mounting (§18.3.5), connections (§18.3.6), NAC (§18.3.7) |
| NFPA 72-2022 A.18.3.7.1 | NAC design: 24 VDC appliances operate from 16 to 33 VDC; maximum listed current; voltage drop |
| NFPA 72-2022 §18.4.1 | Audible general: ambient over 105 dBA → visual appliances; 110 dBA maximum; documentation of design levels |
| NFPA 72-2022 §18.4.2 | Temporal-3 evacuation signal (ANSI/ASA S3.41); 2022 duration rule; synchronization |
| NFPA 72-2022 §18.4.3 | Temporal-4 CO signal |
| NFPA 72-2022 §18.4.4 | Public mode: 15 dB / 5 dB, 5 ft, dBA; elevators, restrooms, ambient noise reduction |
| NFPA 72-2022 §18.4.5 | Private mode: 10 dB / 5 dB |
| NFPA 72-2022 §18.4.6 | Sleeping areas: 75 dBA at the pillow, barriers, 520 Hz |
| NFPA 72-2022 §18.4.8 | Exit marking audible notification appliances |
| NFPA 72-2022 §18.4.9 | Audible location: 90 in. / 6 in.; combination A/V per §18.5.5 |
| NFPA 72-2022 §18.5.3 | Flash rate 1 to 2 Hz, clear or white light, 1000 cd maximum |
| NFPA 72-2022 §18.5.5.1 | Wall-mounted visual: entire lens between 80 and 96 in.; low ceilings |
| NFPA 72-2022 §18.5.5.5 | Ceiling-listed visual: minimum 80 in. or the ceiling height (2022) |
| NFPA 72-2022 Table 18.5.5.7.1(a) | Room spacing: wall-mounted visual appliances (candela by room size) |
| NFPA 72-2022 Table 18.5.5.7.1(b) | Room spacing: ceiling-mounted visual appliances (10, 20, or 30 ft ceiling height) |
| NFPA 72-2022 §18.5.5.7.2 | Synchronization: more than two appliances in the field of view |
| NFPA 72-2022 §18.5.5.8 | Corridors 20 ft wide or less: 15 cd, 15 ft from each end, 100 ft between appliances |
| NFPA 72-2022 §18.5.5.10 | Sleeping rooms: 110 or 177 cd by distance from the ceiling (24 in.); within 16 ft of the pillow |
| NFPA 72-2022 Table 14.4.3.2 | Testing: alarm notification appliances (audible, textual, visual) and exit marking |
Chapter vocabulary
- Notification appliance
- A component (horn, strobe, speaker, etc.) activated by the system that alerts occupants with audible, visual, tactile, or textual output.
- Notification appliance circuit (NAC)
- A circuit or pathway connected directly to notification appliances; it must comply with Chapter 12 (§18.3.7).
- Visual notification appliance (strobe)
- An appliance that alerts by sight; NFPA 72-2022 calls it 'visual' (formerly 'visible').
- Effective intensity (cd)
- The luminous intensity of a flashing light expressed as an equivalent steady light; it is the cd value used in the spacing tables.
- Average ambient sound level
- The A-weighted RMS level measured over the period when people are present, or 24 hours, whichever is less.
- Minimum hearing distance
- The closest distance an occupant's ear can be to an audible appliance; the 110 dBA maximum applies there (new definition in 2022).
- Public mode
- Audible or visual signaling to the general occupants of an area; requires 15 dB above the average ambient.
- Private mode
- Signaling only to the persons directing the emergency response (for example, a nurses' station); requires 10 dB above the average ambient.
- Temporal-3 (T3) pattern
- The standard evacuation signal per ANSI/ASA S3.41: 0.5 s on / 0.5 s off three times, then 1.5 s off.
- Temporal-4 (T4) pattern
- The CO signal: four cycles of 100 ms on / 100 ms off, then 5 s off.
- Low-frequency signal (520 Hz)
- An audible signal with a fundamental frequency of 520 Hz ±10 percent, required to awaken occupants in sleeping areas.
- Synchronization
- Visual appliances flashing at the same time; required when more than two are in the same field of view.
- Field of view
- The area an observer can see from one position; it determines whether strobes must be synchronized.
- Multi-candela (selectable) appliance
- A strobe with a switch or jumper to choose the intensity (for example, 15, 30, 75, 95, 110 cd); set it per the approved drawings.
- End-of-line (EOL) resistor
- A resistor at the end of a Class B circuit that lets the panel supervise the continuity of the wiring.
- Reverse polarity supervision
- A method in which the NAC is supervised in standby with reversed polarity (the appliance diodes block current) and the polarity is reversed in alarm to energize the appliances.
- Sync module
- A listed device that sends the manufacturer's synchronization protocol to the appliances on one or more NACs.
- Exit marking audible notification appliance
- A directional sounder that guides occupants to exits and areas of refuge (§18.4.8).
- Sleeping area
- A space intended or reasonably used for sleeping (hotel room, room with a sofa bed, on-call room); requires 75 dBA, 520 Hz, and 110 or 177 cd visual appliances.
- Textual visual notification appliance
- An appliance that displays alphanumeric or pictorial messages, such as a message sign.
- Tactile notification appliance
- An appliance that alerts by touch (for example, a bed shaker); its performance is evaluated per UL 1971.
- Masked threshold (narrow band)
- The minimum level at which a tone can be heard in the presence of noise; the alternate method requires exceeding it by 10 dB per octave band or 13 dB per one-third octave band.
- Type 2 sound level meter
- An instrument meeting ANSI/ASA S1.4 Type 2, required to measure sound pressure levels during acceptance testing (A-weighting, FAST).
45 practice questions cover this chapter, each with an explanation and the code section. Get lifetime access or try the free practice exam.
More Level I 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