FST Fire Alarm Systems 3 — Questions and Answers
Question 1: An addressable fire alarm system differs from a conventional system primarily in that addressable systems:
- Use only wireless devices
- Identify the specific device that activated rather than just the zone (Correct answer)
- Require less wiring
- Are only used in high-rise buildings
Correct answer: Identify the specific device that activated rather than just the zone
Addressable systems assign a unique address to each device, allowing the panel to pinpoint the exact location of an activated detector or pull station.
Question 2: A 'pre-signal' feature on a fire alarm control panel means:
- The panel sends a signal before any fire is detected
- Alarms notify a central station before sounding in the building
- A preliminary alarm is sent to select staff before general evacuation is initiated (Correct answer)
- The panel requires two device activations before alarming
Correct answer: A preliminary alarm is sent to select staff before general evacuation is initiated
A pre-signal system alerts trained personnel (security, management) before activating general occupant notification, allowing investigation before evacuation.
Question 3: Under NFPA 72, how soon must a supervising station acknowledge an alarm signal during business hours?
- 15 seconds
- 90 seconds (Correct answer)
- 5 minutes
- 10 minutes
Correct answer: 90 seconds
NFPA 72 requires a supervising station to acknowledge and act on an alarm signal within 90 seconds of receipt.
Question 4: A fire alarm control panel displays a 'supervisory' signal. This indicates:
- The system is in full alarm mode
- An off-normal condition in a fire protection system component (Correct answer)
- A device has been removed for maintenance
- The battery has failed
Correct answer: An off-normal condition in a fire protection system component
A supervisory signal indicates an off-normal condition in a suppression or detection system component, such as a closed sprinkler valve, requiring investigation.
Question 5: When installing smoke detectors on smooth ceilings, NFPA 72 generally requires detectors be placed no more than how far apart?
- 15 feet
- 30 feet
- 50 feet (Correct answer)
- 60 feet
Correct answer: 50 feet
NFPA 72 uses a 30-foot spacing radius, which translates to no more than 30 feet from any point on the ceiling to the nearest detector, equivalent to approximately 50-foot center-to-center spacing in a grid.
Question 6: Which type of notification appliance is specifically designed to alert hearing-impaired occupants?
- Horn
- Chime
- Strobe light (Correct answer)
- Speaker
Correct answer: Strobe light
Strobe lights (visible notification appliances) are required to alert hearing-impaired individuals by producing a high-intensity flashing light during alarm conditions.
Question 7: A fire alarm system's 'end-of-line' resistor on a Class B circuit serves what purpose?
- Limits current to prevent overheating
- Allows the panel to detect an open or short circuit fault (Correct answer)
- Boosts signal strength over long wire runs
- Provides surge protection
Correct answer: Allows the panel to detect an open or short circuit fault
The end-of-line resistor creates a measurable current loop so the panel can distinguish between normal, open-circuit (trouble), and short-circuit (fault) conditions.
FST Fire Alarm Systems 3
An addressable fire alarm system differs from a conventional system primarily in that addressable systems: