During a power failure, a fire alarm backup battery must last at least how long?

During a power failure, a fire alarm backup battery must last at least how long?

• A. At least 24 hours plus 5 minutes sounding alarm
• B. At least 12 hours
• C. At least 6 hours
• D. At least 48 hours

Answer: (A)

When a power outage occurs, the fire alarm system must keep working on its backup power for a sufficient period to ensure occupants are notified. The requirement specifies at least 24 hours of autonomy, and in addition, the system must be able to sound alarms for at least five minutes on backup power. This combination guarantees continuous notification through a full day and a short additional alarm window even if the outage lasts longer. Shorter durations like 12 or 6 hours wouldn’t meet the standard, and 48 hours goes beyond the usual requirement.

When a power outage occurs, the fire alarm system must keep working on its backup power for a sufficient period to ensure occupants are notified. The requirement specifies at least 24 hours of autonomy, and in addition, the system must be able to sound alarms for at least five minutes on backup power. This combination guarantees continuous notification through a full day and a short additional alarm window even if the outage lasts longer. Shorter durations like 12 or 6 hours wouldn’t meet the standard, and 48 hours goes beyond the usual requirement.