What are the secondary power supply requirements for a household system?

What are the secondary power supply requirements for a household system?

• A. 12 hours, 2 min in alarm
• B. 24 hours normal operation, 4 min in alarm
• C. 8 hours, 8 min in alarm
• D. 36 hours, 6 min in alarm

Answer: (B)

The secondary power supply is the backup power that keeps the fire alarm system running when the main power is out. For a household system, this backup must be able to power the system for a full day of normal operation and also sustain it through the alarm period. That means the backup battery should provide enough energy to keep the panel and all signaling devices operating for 24 hours when power is unavailable, and still have enough capacity to run the system for at least a few minutes during an alarm. The 4 minutes in alarm ensures the system completes the alarm cycle, signals occupants, and maintains visibility and sound while power restoration or additional power resources are arranged. The other durations don’t align with these practical standby and alarm requirements for residential installations.

The secondary power supply is the backup power that keeps the fire alarm system running when the main power is out. For a household system, this backup must be able to power the system for a full day of normal operation and also sustain it through the alarm period. That means the backup battery should provide enough energy to keep the panel and all signaling devices operating for 24 hours when power is unavailable, and still have enough capacity to run the system for at least a few minutes during an alarm. The 4 minutes in alarm ensures the system completes the alarm cycle, signals occupants, and maintains visibility and sound while power restoration or additional power resources are arranged. The other durations don’t align with these practical standby and alarm requirements for residential installations.