Under NFPA 72, which subsection addresses secondary power supply for household fire alarm systems?

Under NFPA 72, which subsection addresses secondary power supply for household fire alarm systems?

• A. 7.5.3.1
• B. 14.4.7
• C. 29.9.3 (2)
• D. 24.8.17

Answer: (C)

Secondary power supply for household fire alarm systems is about ensuring the system keeps operating when the main power is lost. NFPA 72 designates this requirement under the residential power source provisions, specifying that a standby energy source—typically a battery or central backup—must be provided, kept charged, and capable of sustaining the system for the required duration during a power outage. It also covers testing and maintenance so the backup remains reliable. This backing keeps all smoke alarms and any interconnected devices audible and functional when normal power is unavailable, which is the life-safety purpose of the backup power rule. Other NFPA 72 sections address different topics like wiring, supervision, or signaling details, but they do not specifically govern the backup power for dwelling systems.

Secondary power supply for household fire alarm systems is about ensuring the system keeps operating when the main power is lost. NFPA 72 designates this requirement under the residential power source provisions, specifying that a standby energy source—typically a battery or central backup—must be provided, kept charged, and capable of sustaining the system for the required duration during a power outage. It also covers testing and maintenance so the backup remains reliable. This backing keeps all smoke alarms and any interconnected devices audible and functional when normal power is unavailable, which is the life-safety purpose of the backup power rule. Other NFPA 72 sections address different topics like wiring, supervision, or signaling details, but they do not specifically govern the backup power for dwelling systems.