NFPA Journal

I often find contractors, engineers, and authorities having jurisdiction (AHJs) referring to a single chapter of NFPA 72®, National Fire Alarm and Signaling Code®, to define the requirements of a fire alarm system installation. This seems to happen frequently, even though the code requires that all chapters must apply together to determine all of the applicable code requirements for a code-compliant fire alarm or emergency communications system installation.

Chapter 1, section 1.1.2 states that “the provisions of this chapter apply throughout the code unless otherwise noted.” Section 1.3.5 goes on to state that “the requirements of Chapters 7, 10, 12, 14, 17, 18, 21, 23, 24, 26, and 27 shall apply unless otherwise noted in the specific chapter.” The lone exception is Chapter 29, Single- and Multiple-Station Alarms and Household Signaling Systems, which the code states “is designed to stand alone unless it specifically references an earlier chapter.”

I have noted before that NFPA 72 does not actually require the installation of a fire alarm system in any occupancy. However, once a fire alarm system is mandated by the building code or any other requirement of an AHJ—including NFPA 101®, Life Safety Code®—then that system installation must comply with the requirements of NFPA 72. Fire alarm system design and installation professionals should always first reference the Fundamentals chapter of the code, including section 10.1.1, which states that “the basic functions of a complete fire alarm and/or signaling system shall comply with the requirements of this chapter.”

Some of the most common misconceptions held by design and installation professionals relate to the information contained in Chapter 12. This chapter details various performance and survivability characteristics of signaling pathways and does not require the use of any particular class of signaling pathway for a fire alarm system. Typically, the design drawings will specify the class of circuit required. Except in local jurisdictions that use their own local ordinance to require a designated class of circuit, the designer has total responsibility to determine which class of circuit meets the performance goals of the owner, as dictated by the type of occupancy.

Another misconception in Chapter 12 is that the code requires pathway survivability. Although this chapter describes four levels of circuit survivability, the chapter does not in fact require any of these levels. Either a building code requirement or a requirement elsewhere in NFPA 72 generates the requirement for survivability.

For example, section 24.4.8.6.1 states that when a fire alarm system initiates partial evacuation and relocation, the design and installation of the circuits interconnecting the speakers (i.e., the speaker riser circuit) in the building must prevent an attack by fire within one signaling zone from impairing the operation or control of the notification appliances outside that signaling zone. Additionally, section 24.4.8.6 states that when a circuit from in-building fire emergency voice/alarm control equipment—components that depend on control equipment located in another part of the building—enters still other parts of the building, the circuits between the dependent controls “shall be protected against attack by fire by the protection provided by a Level 2 or Level 3 pathway survivability.”

As you can see, the requirement to use two-hour circuit integrity, or other two-hour rated solutions, does not come from Chapter 12 but from Chapter 24.

The point here is that design and installation professionals must carefully read all of NFPA 72 to understand the entire set of requirements for a code-compliant fire alarm system installation.

Wayne D. Moore is vice president at Jensen Hughes. NFPA members and AHJs can use the Technical Questions tab to post queries on NFPA 72 at nfpa.org/72.