NFPA 72 Fundamentals
Power Supplies, Signal Priority and Timing, Circuit Classes and Testing (Chapters 10, 12 and 14)
NFPA 72-2019 National Fire Alarm and Signaling Code (DBPR CIB reference list); read in the NFPA free-access viewer 2026-09-20/21 · Reviewed 2026-09-21
"Alarms / Limited Energy" is 14–16 questions on the Unlimited exam — the second-largest technical block. The NEC half (Articles 722/725/760) is in the limited-energy lesson; this lesson is the NFPA 72-2019 half. Chapter 10 sets the rules every fire alarm system must meet, Chapter 12 defines what "Class A / Class B / Class X" mean, and Chapter 14 is the inspection and testing schedule. Learn the numbers: 85/110 %, 6 ft / 15 in., 10 s, 24 h + 5 min, 15 min, 20 %, 48 h, 90 s, 200 s, 10 s, 60–180 min, 18 months, 5 years, 1 year.
1. Equipment and installation basics — 10.3, 10.4
- Everything is listed for the purpose it is used for; devices powered from an initiating device circuit (IDC) or signaling line circuit (SLC) are listed for use with that control unit (10.3).
- Equipment must perform at 85 % and 110 % of nameplate primary and secondary voltage, at 32 °F and 120 °F, and at 85 % RH / 86 °F (10.3.5).
- Devices are mounted so vibration or jarring cannot cause accidental operation or failure.
- Control unit displays and controls: highest switch/lamp/display not more than 6 ft above the finished floor, lowest not less than 15 in. (10.4.4).
- In areas not continuously occupied, a smoke detector (heat detector where ambient conditions prohibit smoke) protects each control unit, NAC power extender and supervising station transmitter location (10.4.5) — not required at dedicated-function units that give no local or supervising-station notification.
- Manual alarms may be initiated only by a listed manual fire alarm box, a key-operated means, or a means in a locked cabinet / equivalent protection (10.4.7).
- 10.5 personnel: designers, installers and service personnel are qualified by state/local licensure, certification by an organization acceptable to the AHJ, or manufacturer certification for the specific type and brand; programming personnel are certified by the manufacturer.
The rest of this lesson is for members.
The rest of this lesson, its quiz, all 6 lessons in this module and every mock exam open with the 7-day pass for $9. If you keep going, that $9 comes off lifetime.