CFPS Detection and Alarm Systems 3 — Questions and Answers
Question 1: In an addressable fire alarm system, each initiating device is assigned a unique address primarily to:
- Reduce the number of conductors required in the building
- Allow the control panel to pinpoint the exact location of an alarm or fault (Correct answer)
- Enable wireless communication with the panel
- Increase the number of devices per circuit
Correct answer: Allow the control panel to pinpoint the exact location of an alarm or fault
Addressable systems allow the FACP to identify which specific device initiated an alarm or reported a fault, enabling faster response and simpler troubleshooting.
Question 2: NFPA 72 requires that the primary power supply for a fire alarm control unit be supplied by:
- A dedicated branch circuit, minimum 20-amp, labeled at the panel (Correct answer)
- Any available 15-amp general-purpose circuit
- A UPS unit with 72-hour backup
- Battery backup only when utility power is unavailable
Correct answer: A dedicated branch circuit, minimum 20-amp, labeled at the panel
NFPA 72 mandates a dedicated, labeled branch circuit to ensure the fire alarm system cannot be de-energized by tripping a shared breaker.
Question 3: The maximum allowable secondary power (battery) standby duration for a fire alarm system in a non-protected premises application is:
- 4 hours
- 24 hours (Correct answer)
- 60 hours
- 72 hours
Correct answer: 24 hours
NFPA 72 requires 24 hours of standby followed by 5 minutes of alarm for non-protected premises systems, unless otherwise specified.
Question 4: Which type of smoke detector is generally MORE prone to false alarms from cooking aerosols?
- Projected beam detector
- Photoelectric detector
- Ionization detector (Correct answer)
- Air-sampling detector
Correct answer: Ionization detector
Ionization detectors respond to the tiny combustion particles produced by cooking and are more easily triggered by steam and cooking smoke than photoelectric types.
Question 5: A waterflow alarm switch on a wet-pipe sprinkler system is classified under NFPA 72 as which type of initiating device?
- Supervisory initiating device
- Manual pull station
- Automatic sprinkler flow alarm initiating device (Correct answer)
- Trouble initiating device
Correct answer: Automatic sprinkler flow alarm initiating device
Waterflow switches are automatic initiating devices that signal an alarm when water flows through the sprinkler system, indicating a sprinkler has operated.
Question 6: When a fire alarm notification appliance circuit (NAC) is wired as Class A, the return conductor must:
- Share the same conduit as the supply conductor to save material
- Return to the fire alarm control panel through a separate path (Correct answer)
- Connect to a secondary FACP at the opposite end of the building
- Terminate at the last appliance on the circuit
Correct answer: Return to the fire alarm control panel through a separate path
Class A circuits require a separate return path back to the panel so that a single open fault does not disable any devices downstream of the break.
Question 7: Under NFPA 72, the maximum sound pressure level for audible notification appliances in sleeping areas is limited to protect occupants from:
- Sleep disruption during routine testing
- Permanent hearing damage from high-intensity signals (Correct answer)
- Interference with voice intelligibility signals
- Damage to building structural elements
Correct answer: Permanent hearing damage from high-intensity signals
NFPA 72 caps output at 110 dBA at the pillow to prevent permanent hearing damage from excessively loud alarms during nighttime occupancy.
CFPS Detection and Alarm Systems 3
In an addressable fire alarm system, each initiating device is assigned a unique address primarily to: