FST Fire Detection & Suppression Systems 5 — Questions and Answers
Question 1: In a fire alarm system, what does a 'supervisory signal' indicate?
- A fire has been detected
- A system component needs evacuation
- An off-normal condition in a fire protection system requiring attention (Correct answer)
- The system has been disabled by the AHJ
Correct answer: An off-normal condition in a fire protection system requiring attention
A supervisory signal indicates an off-normal condition in a fire protection system (such as a closed sprinkler valve) that requires investigation but is not necessarily a fire.
Question 2: What is the minimum ceiling height at which a standard upright or pendent sprinkler may require a longer deflector-to-ceiling distance adjustment?
- 8 feet
- 12 feet
- There is no adjustment for ceiling height
- Only when ceiling exceeds 20 feet (Correct answer)
Correct answer: Only when ceiling exceeds 20 feet
NFPA 13 requires additional sprinkler design consideration and adjustments for ceiling heights exceeding 20 feet due to fire plume dynamics at greater heights.
Question 3: A fire technician finds a sprinkler valve locked in the closed position. According to NFPA 25, this should be immediately reported as:
- A routine maintenance item
- An impairment requiring proper impairment procedures (Correct answer)
- A false alarm condition
- A supervisory signal to be logged only
Correct answer: An impairment requiring proper impairment procedures
Any condition that leaves fire protection equipment out of service must be handled through formal impairment procedures, including notifying the AHJ and taking compensating measures.
Question 4: Which of the following is a PRIMARY advantage of an addressable fire alarm system over a conventional zoned system?
- Lower installation cost
- Each device has a unique address enabling pinpoint identification (Correct answer)
- No requirement for a fire alarm control panel
- Elimination of all wiring in the building
Correct answer: Each device has a unique address enabling pinpoint identification
Addressable systems assign a unique identifier to each device, allowing the FACP to identify the exact detector or device that activated rather than only the zone.
Question 5: The required sound pressure level for audible notification appliances in sleeping areas per NFPA 72 is:
- 55 dBA at the pillow level
- 75 dBA at the pillow level (Correct answer)
- 85 dBA at the pillow level
- 65 dBA at the pillow level
Correct answer: 75 dBA at the pillow level
NFPA 72 requires a minimum of 75 dBA measured at the pillow in sleeping areas to ensure occupants can be awakened by the alarm.
Question 6: Foam suppression systems are most appropriate for protecting:
- Computer server rooms
- Electrical switchgear rooms
- Aircraft hangars and flammable liquid storage areas (Correct answer)
- Cold storage and freezer warehouses
Correct answer: Aircraft hangars and flammable liquid storage areas
Foam systems are specifically effective for flammable liquid fires (Class B) because foam creates a blanket that excludes oxygen and prevents vapor release, making them ideal for hangars and fuel storage.
Question 7: What is the purpose of a tamper switch on a sprinkler system control valve?
- To prevent unauthorized discharge of the system
- To signal the FACP if the valve is moved from the fully open position (Correct answer)
- To lock the valve permanently open
- To test the system without flowing water
Correct answer: To signal the FACP if the valve is moved from the fully open position
A tamper switch (supervisory switch) monitors the valve position and sends a supervisory signal to the FACP if the valve is partially or fully closed, alerting personnel to an impairment.
FST Fire Detection & Suppression Systems 5
In a fire alarm system, what does a 'supervisory signal' indicate?