S95 Initiating Devices 3 — Questions and Answers
Question 1: A fixed-temperature heat detector activates when the ambient temperature at the device reaches a predetermined level. What is the most common fixed-temperature rating for standard applications?
- 100°F (38°C)
- 135°F (57°C) (Correct answer)
- 165°F (74°C)
- 212°F (100°C)
Correct answer: 135°F (57°C)
The most common fixed-temperature rating for standard environments is 135°F (57°C), which is low enough to detect abnormal heat while remaining above typical ambient temperatures.
Question 2: A rate-of-rise heat detector triggers an alarm when the temperature increases by more than how many degrees Fahrenheit per minute?
- 5°F per minute
- 12°F per minute
- 15°F per minute
- 25°F per minute (Correct answer)
Correct answer: 25°F per minute
Rate-of-rise detectors are designed to alarm when temperature increases at a rate exceeding approximately 12–15°F per minute, indicating a rapidly developing fire condition.
Question 3: Which type of heat detector is MOST appropriate for an environment where slow-smoldering fires are expected but ambient temperatures may already be high?
- Rate-of-rise only detector
- Fixed-temperature detector at a higher rating (Correct answer)
- Combination rate-of-rise and fixed-temperature detector
- Projected beam smoke detector
Correct answer: Fixed-temperature detector at a higher rating
In high-ambient-temperature environments, a fixed-temperature detector set at an appropriately higher rating ensures the detector does not false-alarm while still responding to an actual fire.
Question 4: After activation, which type of heat detector must be replaced rather than reset?
- Rate-of-rise detector
- Electronic thermal detector
- Fusible-link or fusible-alloy fixed-temperature detector (Correct answer)
- Combination detector in test mode
Correct answer: Fusible-link or fusible-alloy fixed-temperature detector
Fusible-link or fusible-alloy detectors operate by melting an alloy at a set temperature; once activated, the element is destroyed and the entire detector must be replaced.
Question 5: A manual pull station must be installed at what height above the finished floor per NFPA 72?
- Between 2.5 and 4 feet
- Between 3.5 and 5 feet
- Between 42 and 54 inches (Correct answer)
- Between 48 and 60 inches
Correct answer: Between 42 and 54 inches
NFPA 72 requires manual pull stations to be mounted with the operable part between 42 inches (3.5 ft) and 54 inches (4.5 ft) above the finished floor.
Question 6: Where must a manual pull station be located relative to a building exit?
- Within 5 feet of the exit door on the egress side (Correct answer)
- At least 10 feet from the exit to avoid accidental activation
- At the main fire alarm control panel only
- Only at stairwell landings, not at exit doors
Correct answer: Within 5 feet of the exit door on the egress side
NFPA 72 requires manual pull stations to be located within 5 feet of the exit door on the path of egress so occupants can activate the alarm as they exit.
Question 7: A double-action manual pull station requires the user to perform what sequence before it activates?
- Push the button, then pull the handle
- Lift a cover and then pull the handle (Correct answer)
- Turn a key and then pull
- Pull the handle twice in succession
Correct answer: Lift a cover and then pull the handle
Double-action pull stations require lifting, breaking, or opening a protective cover before the handle can be pulled, reducing accidental activations.
S95 Initiating Devices 3
A fixed-temperature heat detector activates when the ambient temperature at the device reaches a predetermined level.
What is the most common fixed-temperature rating for standard applications?