What are typical power requirements for a fire alarm control panel, including battery backup duration for NFPA compliance?

• A. The panel is normally powered by low-voltage DC with a tiny battery backup.
• B. The panel requires 12 V AC with a 6-hour backup.
• C. The panel is normally powered from 120/208/240 V AC with a battery backup sized to provide at least 24 hours of standby operation and sufficient capacity to support the alarm load during outages.
• D. The panel runs on solar power with unlimited uptime.

Answer: (C)

The key idea is that a fire alarm control panel must have a dependable power source with a battery backup large enough to keep the system running during a power outage. NFPA 72 requires the panel to be normally supplied from standard building power (the common voltages used are 120/208/240 V AC) and to include a battery bank that can provide at least 24 hours of standby operation, with enough capacity to support the alarm load for the duration of the outage. This ensures the system can continue to monitor, announce, and transmit signals even when the main power is out, which is critical for occupant safety.

That’s why the option describing normal AC power from 120/208/240 V with a battery backup sized for at least 24 hours of standby and the full alarm load is the best fit. It aligns with how fire alarm systems are designed to stay operable during outages and meet NFPA expectations for reliability.

The other scenarios don’t fit typical NFPA practice: a tiny backup on a low-voltage DC supply isn’t sufficient for the full system, a single 12 V AC supply with only a 6-hour backup won’t meet the standard 24-hour standby requirement, and solar power with unlimited uptime isn’t how these systems are normally documented or guaranteed to operate under all conditions.