When aDACTis the only method of off-premises signal transmission, itmustbe connected totwo separate telephone linesto ensure redundancy in case one line fails.

NFPA 72 (2022), Section 26.6.4.4.4.1:

“DACTs shall be connected to two separate phone lines (one primary, one secondary). Loss of the primary line shall result in a supervisory signal.”

This redundancy ensures system reliability when using traditional telephone-based communication.

Correct answer: D. Two separate phone lines are required

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NFPA 72 requires annual testing to ensuretrouble signalsare correctly transmitted to the off-premises monitoring location (e.g., central station).

NFPA 72 (2022), Table 14.4.3.2 – Testing Frequencies and Methods:

Under “Off-Premises Transmission Equipment,”trouble signalsare testedannually.

This ensures that the system will properly report malfunctions.

Correct answer: D. Annually

Household fire alarm systems have different performance requirements from commercial systems, but still must support essential alarm functions under loss of primary power.

NFPA 72 (2022), Section 29.10.5.1.1:

“The secondary power supply shall be capable of powering the system under quiescent load for 24 hours and then capable of operating the system during alarm for a period of 4 minutes (for general fire alarm) or 10 minutes (for household fire alarm systems).”

Correct answer: C. 24 hours in the normal condition followed by 10 minutes of alarm

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NFPA 72 requiressound pressure level measurementsto verify that audibility meets code requirements. This must be done duringinitial acceptanceandreacceptance testing(e.g., when system changes occur).

NFPA 72 (2022), Section 18.4.7.2:

"Sound pressure level measurements shall be taken and documented during acceptance and reacceptance testing."

Correct answer: B. Sound pressure levels are required to be taken during initial acceptance and reacceptance testing.

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NFPA 72 requires thattrouble signalsbe inspectedweeklyon monitored fire alarm systems toensure the system can detect and report problems in a timely manner.

NFPA 72 (2022), Table 14.3.1 — Inspection Frequencies:

"Supervising station systems — Trouble signals"→Weekly

This ensures any open circuits, ground faults, or system issues are discovered promptly.

Correct answer: A. Weekly

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Engine-driven generators used for emergency power arenot governed directly by NFPA 72. Instead, their installation and testing requirements are found in:

NFPA 110 – Standard for Emergency and Standby Power Systems

NFPA 110 (2022), Chapter 8details howengine-driven generatorsmust be tested, including runtime, load testing, and maintenance intervals.

NFPA 72 references NFPA 110whenever standby/emergency power is used for fire alarm systems.

Correct answer: D. NFPA 110

The need toclean devicessuch as detectors is influenced by theenvironment they are installed in, not just their type or age. Dusty, smoky, or humid environments will require more frequent cleaning.

NFPA 72 (2022), Section 14.4.1.3:

“The frequency of cleaning shall be determined by the manufacturer’s instructions and the local ambient conditions.”

Correct answer: C. Local ambient conditions

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