Overdue Inspection and Undersized Battery
A 120,000 sq ft K-12 school has a 280-device addressable fire alarm installed 8 years ago. The last annual inspection was 3 years ago. The panel history shows 14 trouble events in the past year, including 6 dirty smoke detector troubles and 2 ground faults. The standby battery is a 24 VDC, 18 Ah unit. Connected standby load is 1.2 A; alarm load is 4.5 A. The system is required to provide 24 hours of standby followed by 5 minutes of alarm. The contractor proposes to clean the six detectors, clear the ground faults, and perform a 20 percent sample test of initiating devices because the system is older. The owner wants a certificate of compliance by Friday. No battery load test records exist.
1. Calculate the required battery capacity and determine whether the 18 Ah battery is adequate.
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Standby energy = 1.2 A × 24 h = 28.8 Ah. Alarm energy = 4.5 A × 5/60 h = 0.375 Ah. Total = 29.175 Ah. Apply the 1.25 aging and temperature factor: 29.175 × 1.25 = 36.47 Ah. The installed 18 Ah battery is not adequate. It also lacks load-test records, and its actual capacity at 1.2 A may be lower than the label due to aging. The contractor should replace it with a battery of at least 36.5 Ah, such as a 40 Ah unit, verify the enclosure and charger ratings, and perform a load test. The battery calculation should be documented in the inspection report.
2. Is a 20 percent sample test of initiating devices acceptable for this system? What test scope is required?
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A 20 percent sample is not an acceptable substitute for the annual testing required by NFPA 72. The annual inspection and test must cover all initiating devices, notification appliances, and the associated control equipment as required by the applicable tables, unless a specific code provision allows a sampling method for that device type. Smoke detectors need annual functional testing and sensitivity verification where required; dirty detector troubles and ground faults are deficiencies that must be corrected and retested. The three-year gap in annual inspections makes the backlog worse. The contractor should develop a complete test plan, correct the ground faults, clean or replace detectors as needed, test notification audibility, and verify battery capacity.
3. Can the contractor issue a certificate of compliance by Friday? What should be documented?
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A certificate should not be issued until the deficiencies are corrected and the required tests are completed. Friday may be possible only if the contractor can complete the full test, replace the battery, clear the ground faults, and resolve the detector troubles. The documentation should include the device test records, battery calculation and load test, ground-fault repair details, notification appliance test results, and a list of any remaining impairments. If impairments remain, the owner should receive a written report and the AHJ should be notified as required. Issuing a certificate based on a sample test and an undersized battery would misrepresent the system condition.