Detectors form the backbone of any fire alarm system, ensuring that a potentially dangerous situation will be detected early and the occupants notified of the event. To detect fires effectively, it is critical that the proper detector be used and installed according to all applicable codes and the manufacturer’s installation instructions. To see if your fire system designs are up to snuff, take the following quiz.

ANSWERS BELOW.

1. NFPA 72 is the National Fire Alarm Code.
   1. True
   2. False


2. What is the maximum number of water flow switches permitted to be connected to a single initiating device circuit?
   1. 1
   2. 2
   3. 3
   4. 4
   5. 5


3. What is the maximum number of supervisory devices permitted to be connected to a single initiating device circuit?
   1. 10
   2. 20
   3. 30
   4. 40
   5. 50


4. In new one and two family dwellings, which of the following are the requirements for smoke detector installation?
   1. In all sleeping rooms
   2. Outside of each separate sleeping area
   3. On each level of the dwelling
   4. All of the above
   5. None of the above


5. When installing initiating devices, they shall be supported independently of their attach-ment to the circuit conductors.
   1. True
   2. False


6. A ceiling is considered smooth if it is uninterrupted by continuous projections, such as solid joists, beams or ducts, extending more than how many inches below the ceiling surface?
   1. 2
   2. 4
   3. 6
   4. 8
   5. 12


7. When reading the Fire Alarm Code, the word “shall” indicates a recommendation but is not required.
   1. True
   2. False


8. When reading the Fire Alarm Code, the word “should” indicates a mandatory requirement.
   1. True
   2. False


9. Which of the following is an example of a smoke detector?
   1. Cloud chamber
   2. Ionization
   3. Photoelectric
   4. Any of the above
   5. None of the above


10. For complete detector coverage, detectors must always be installed in concealed accessible spaces above suspended ceilings that are used as a return air plenum.
    1. True
    2. False


11. When the height of a ceiling is 15 feet, which of the following spacing reduction factors must be used to properly locate heat detectors?
    1. 0.91
    2. 0.84
    3. 0.77
    4. 0.71


12. When mounting smoke detectors on a wall, they should be installed between 4 and 12 inches down from the ceiling to the top of the detector.
    1. True
    2. False


13. Ionization system smoke detectors must be functionally tested annually.
    1. True
    2. False


14. Fixed-temperature heat-sensing devices are marked with a color code indicating their temperature classification.
    1. True
    2. False


15. What is the minimum mounting height above the finished floor (AFF) for a wall-mounted audible notification device?
    1. 72 inches to top of device
    2. 72 inches to bottom of device
    3. 90 inches to top of device
    4. 90 inches to bottom of device

What’s Wrong with This?

Wally ‘Larman installed a fire alarm system for a new single dwelling home without any basement, installing a smoke detector in each bedroom as shown in this diagram, along with an approved control, command center and notification appliances. He used only listed equipment and wired each device according to the manufacturer’s instructions. When the installation was completed, Wally tested it to make sure everything functioned as designed, but when the inspector arrived, he was not satisfied. Can you see what Wally did wrong and what he must do to correct the problem?

5-Minute Tech Quiz Answers

Here are the answers to the 5-Minute Tech Quiz and What’s Wrong with This? that appears on page 53.

1. a
2. e — NFPA 72 6.8.5.5.2 states, “The number of water flow switches permitted to be connected to a single initiating device circuit shall not exceed five.”
3. b — NFPA 72 6.8.5.7.2 states, “The number of supervisory devices permitted to be connected to a single initiating device circuit shall not exceed 20.”
4. d
5. a — NFPA 72 5.4.3 states, “Initiating devices shall be supported independently of their attachment to the circuit conductors.”
6. b
7. b — “Shall” indicates a mandatory requirement; “Should” indicates a recommendation.
8. b
9. d
10. b — NFPA 72 5.5.2.1.5 states, “Detectors shall not be required in concealed, accessible spaces above suspended ceilings that are used as a return air plenum meeting the requirements of NFPA 90A, Standard for the Installation of Air Conditioning and Ventilating Systems, where equipped with smoke detection at each connection from the plenum to the central air-handling system.”
11. c
12. a — NFPA 72 5.7.3.2.1 states, “Spot-type smoke detectors shall be located on the ceiling not less than 100mm (4 in.) from a sidewall to the near edge or, if on a sidewall, between 100mm and 300mm (4 in. and 12 in.) down from the ceiling to the top of the detector.”
13. a

Answer to: What’s Wrong with This?

The inspector is not satisfied because Wally failed to install the proper number of smoke detectors. NFPA 72 11.5.1.1 requires smoke detectors be installed in all sleeping rooms, outside of each separate sleeping area, in the immediate vicinity of the sleeping rooms, and on each level of the dwelling unit, including basements. Wally did install a detector in each sleeping room and on each level, since the home is a single story without a basement, but he failed to install a smoke detector outside of the sleeping rooms. Wally should install an additional smoke detector in the hall outside the sleeping rooms, as shown in this diagram, and after testing the system, request another inspection. Depending upon the AHJ, a self-certification of the correction from Wally without requiring a re-inspection may be acceptable.