Fire alarm systems require a wealth of knowledge to properly design, install and maintain. A number of codes and standards may be applicable depending on where the system is installed and the type of occupancy involved. Failure to follow these codes and standards not only can result in poor system performance but also can lead to loss of life. To determine if you have the requisite knowledge to properly design, install and maintain fire alarm systems, take the following quiz. 

What’s Wrong with This?

Wally `Larman installed a fire alarm system that included a boiler room that measured 240 feet by 120 feet. He selected the correct heat detectors that were rated at 30-ft. spacings and laid them out them as shown in this diagram using 30-ft. spacing between detectors. When the fire marshal reviewed his plans, he rejected them. Can you see what Wally did wrong and what he must do to correct the problem?

1.     Who has final say in the design of a fire alarm system?
    a. NFPA 70
    b. NFPA 101
    c. Local AHJ
    d. State codes

2.     Trouble signals shall be indicated in how many seconds?
    a. 10
    b. 20
    c. 100
    d. 200

3.     An alarm signal shall be indicated within how many seconds of waterflow?
    a. 30
    b. 60
    c. 90
    d. 120

4.     Duct detectors are required on the supply side for HVAC units rated at how many cfm or higher?
    a. 1,000
    b. 2,000
    c. 3,000
    d. 4,000

5.     You always should discard old code books as new ones are released.
    a. True
    b. False

6.     DACTs shall have:
    a. line seizure.
    b. loop start lines.
    c. two communication paths.
    d. All of the above
    e. None of the above

7.     All building and fire codes incorporate the latest revisions of NFPA codes/standards.
    a. True
    b. False

8.     Wiring issues for fire alarms are covered in which NFPA standard?
    a. 10
    b. 20
    c. 70
    d. 80
    e. None of the above

9.     Fire alarm systems may not share components with non-fire alarm systems.
    a. True
    b. False

10.    DACRs require a minimum of two incoming telephone lines.
    a. True
    b. False

11.    Exposed wiring shall be protected within how many feet above the finished floor?
    a. 6
    b. 7
    c. 8
    d. 10
    e. 12

12.    The fire pump supply conductors do not require supervision.
    a. True
    b. False

13.    FPLP cable can be used in riser applications.
    a. True
    b. False

14.    Central station fire alarm systems shall be placarded.
    a. True
    b. False

15.    In a coded local fire alarm system, an alarm signal shall consist of:
    a. one repetition of one complete round.
    b. two repetitions of two complete rounds.
    c. three repetitions of three complete rounds.

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 49.

1. c — While you must follow all applicable codes, the local authority having jurisdiction, (AHJ) has the final say in system design and operation.
2. d — NFPA 72, states, “Trouble signals and their restoration to normal shall be indicated within 200 seconds.”
3. c — NFPA 72, 5.10.2 states, “Initiating of the alarm signal shall occur within 90 seconds of waterflow at the alarm-initiating device when flow occurs.”
4. b
5. b — You should keep old code books because local codes frequently refer to a specific code year.
6. d
7. b
8. c — NFPA 70 is the National Electric Code (NEC) and covers wiring issues for fire alarm systems.
9. b — Although allowed by NFPA 72,, you should check with local AHJs to determine if they also allow fire alarm and non-fire alarm devices to be connected to a single control.
10. a
11. b
12. b — NFPA 72, states, “Supervision of electric power supplying the pump shall be made on the line side of the motor starter. All phases and phase reversal shall be supervised.”
13. a
14. a
15. c — NFPA 72, states, “A coded alarm signal shall consist of not less than three complete rounds of the number transmitted. Each round shall consist of not less than three impulses.”

Answer to: What’s Wrong with This?

Wally’s problem is caused by the spacing of the heat detectors. NFPA 72, states, “The distance between detectors shall not exceed their listed spacing, and there shall be detectors within a distance of one-half the listed spacing, measured at a right angle, from all walls or partitions extending to within 460 mm (18 in.) of the ceiling.” In order to comply with this requirement, Wally must space detectors 15 feet (half the listed 30-ft. spacing) from the sidewalls, as shown in this diagram. Wally should redo the system design as shown in this diagram and resubmit it to the fire marshal for approval. After he receives the approved drawings, he can begin the installation.