Fire Alarm & Suppression Testing Flashcards

During fire alarm commissioning, a voice evacuation system is tested for intelligibility. Which measurement metric is used to quantify speech intelligibility?

Answer: Common Intelligibility Scale (CIS) or Speech Transmission Index (STI)

NFPA 72 and IEC 60849 use the Common Intelligibility Scale (CIS) or Speech Transmission Index (STI) to quantify voice alarm intelligibility, requiring a minimum CIS of 0.7.

A commissioning agent is reviewing the interface between a fire alarm system and a magnetic door holder. What is the correct behavior during an alarm condition?

Answer: The door holder de-energizes, releasing the door to close via its closer

Magnetic door holders are fail-safe devices that de-energize (lose power) upon alarm activation, releasing the door to close automatically under spring tension from the door closer.

What is the purpose of a 'stumping test' or 'end-to-end test' in a fire suppression system commissioning context?

Answer: Testing the system at the furthest point from the riser to verify pressure adequacy

End-to-end or remote test verification confirms that water pressure and flow are adequate at the most hydraulically challenging point in the system.

According to NFPA 25, what is the required frequency for internal inspection of wet-pipe sprinkler system piping in dry climates?

Answer: Every 10 years

NFPA 25 requires internal inspection of wet-pipe system piping every 10 years to check for corrosion, scale, or obstructions that could impair flow.

During commissioning, a fire pump acceptance test reveals the pump delivers 150% of rated flow at less than 65% of rated pressure. What does this indicate?

Answer: The pump impeller is worn or the system has significantly less resistance than designed

At 150% flow, fire pumps should deliver at least 65% of rated pressure per NFPA 20; falling below this indicates impeller wear or a hydraulically undersized system.

A commissioning agent discovers that a fire alarm control panel's ground fault indicator is illuminated during functional testing. What is the required response?

Answer: Identify and correct the ground fault before completing system acceptance

A ground fault must be located and corrected before system acceptance because it can mask other faults and create unreliable system operation.

What information must be verified on sprinkler head installation during a commissioning walk-down to confirm code compliance?

Answer: Temperature rating, orientation (upright/pendent/sidewall), and minimum distance from obstructions

Commissioning inspection must verify each sprinkler's temperature rating matches the ambient conditions, correct orientation is used, and minimum obstruction clearances per NFPA 13 are maintained.