In NFPA 72, regarding household fire alarm systems, which statement is true?

In NFPA 72, regarding household fire alarm systems, which statement is true?

• A. Smoke detection circuits must be locked in.
• B. Smoke detection circuits shall not be required to lock in.
• C. The system must monitor gas detectors.
• D. Duct detectors must be installed.

Answer: (B)

In household fire alarm systems, NFPA 72 does not require smoke-detection circuits to lock in. The initiating devices (smoke detectors) are intended to trigger alarms when smoke is detected, but there’s no mandate that the circuit or detector remain in an alarm state indefinitely or be latched in. This allows the system to reset and return to normal once the condition is resolved or the alarm is acknowledged, which is practical for homes where a transient condition (like cooking smoke) may occur. The other statements aren’t required by typical residential installations: monitoring gas detectors isn’t a standard requirement for a household system, and duct detectors aren’t universally required in dwellings.

In household fire alarm systems, NFPA 72 does not require smoke-detection circuits to lock in. The initiating devices (smoke detectors) are intended to trigger alarms when smoke is detected, but there’s no mandate that the circuit or detector remain in an alarm state indefinitely or be latched in. This allows the system to reset and return to normal once the condition is resolved or the alarm is acknowledged, which is practical for homes where a transient condition (like cooking smoke) may occur.

The other statements aren’t required by typical residential installations: monitoring gas detectors isn’t a standard requirement for a household system, and duct detectors aren’t universally required in dwellings.