The secondary power supply shall automatically provide power to the protected premises fire alarm system within which time frame, whenever the primary power supply fails to provide the minimum voltage required for proper operation?

The secondary power supply shall automatically provide power to the protected premises fire alarm system within which time frame, whenever the primary power supply fails to provide the minimum voltage required for proper operation?

• A. 5 seconds
• B. 10 seconds
• C. 60 seconds
• D. 30 seconds

Answer: (B)

Maintain continuous operation of the fire alarm system by switching to standby power as soon as the main supply can’t meet the minimum voltage. The automatic transfer to the secondary power source is required to happen within about ten seconds of the loss of adequate primary power, so there’s no noticeable interruption to sensors, control circuitry, and notification devices. This short transfer window keeps the system reliably powered during outages, balancing practicality of battery capacity with the safety need for immediate backup. A much tighter window (five seconds) would impose stricter hardware demands, while longer delays (thirty or sixty seconds) could leave the system unpowered long enough to compromise detection and signaling.

Maintain continuous operation of the fire alarm system by switching to standby power as soon as the main supply can’t meet the minimum voltage. The automatic transfer to the secondary power source is required to happen within about ten seconds of the loss of adequate primary power, so there’s no noticeable interruption to sensors, control circuitry, and notification devices. This short transfer window keeps the system reliably powered during outages, balancing practicality of battery capacity with the safety need for immediate backup. A much tighter window (five seconds) would impose stricter hardware demands, while longer delays (thirty or sixty seconds) could leave the system unpowered long enough to compromise detection and signaling.