NFPA 72 code sections · Signal Types & Monitoring
Alarm verification buys 60 seconds — no more
Where permitted by the AHJ, a control unit can use an alarm verification feature for smoke detectors: on first activation it resets the detector and waits to see whether the alarm condition is still present before sounding the alarm. The entire verification period is limited to 60 seconds, the feature only applies to smoke detectors (never to manual boxes, heat detectors or waterflow), and a second detector or any other initiating device during the verification window must trigger an immediate alarm.
NFPA 72 reference
Chapter 23 — Protected Premises Fire Alarm Systems
23.8.5.4 Alarm Verification Feature (23.8.5.4.1 60-second maximum; 23.8.5.4.2 other devices alarm immediately)
References use NFPA 72 2019/2022 numbering — section numbers can shift between editions, so confirm in the edition your AHJ has adopted.
On the job
A hotel programs alarm verification to stop shower-steam false alarms. During acceptance testing the inspector activates a pull station during a detector's verification window and expects an immediate alarm. The panel waits out the detector's delay instead — a programming error. Verification is reconfigured so only smoke detectors are delayed.
Quick check
1. The maximum total alarm verification period is:
2. Alarm verification may be applied to:
3. A pull station activated during a detector's verification window must:
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