In Compliance | NFPA 72
How to meet requirements of the entire code for a new fire alarm system
BY WAYNE D. MOORE
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When working with fire alarm contractors, especially during the acceptance test for a new fire alarm system, it often becomes apparent that they have only reviewed certain chapters of NFPA 72®, National Fire Alarm and Signaling Code®. Typically, these include only the chapters they feel may apply to the particular installation of the building fire alarm system at hand. It also becomes clear that not all contractors own a copy of the code. This becomes apparent when they insist that the fire alarm system “meets the code.” Now that the 2019 edition of NFPA 72 is available, it would be a good time to review how it should be used.
In Chapter 1, subsection 1.2.4, NFPA 72 states that “This code shall not be interpreted to require a level of protection that is greater than that which would otherwise be required by the applicable building or fire code.” The annex explanation for the same section states, “The intent of this paragraph is to make it clear that the protection requirements are derived from the applicable building or fire code, not from NFPA 72.”
I explain to fire alarm contractors and designers that they must meet three codes before they can say that the fire alarm system meets all applicable codes and standards. Those are NFPA 70®, National Electrical Code®, the applicable building or life safety code in force in the jurisdiction, and NFPA 72. Subsection 1.2.4 of NFPA 72, along with the annex section, make it clear that the building or fire code in force in the jurisdiction where they perform the work constitutes the first code they must meet.
Complying with NFPA 72 only means that the system meets the requirements that relate to the system’s operation: signal initiation, transmission, notification, and annunciation. Typically, the design will also describe the levels of performance and the reliability of the fire alarm system, as required by the building code. Fire alarm systems exist to warn the occupants of a fire condition and to summon the first responders for the jurisdiction. To that end, the code’s chapters for initiating devices, notification appliances, and supervising station alarm systems govern the system’s design.
Each of these chapters contains specific requirements related to the system design based on the expected system performance. Chapter 10 provides the information regarding the fundamental requirements for a system design and includes requirements such as the need for early warning fire detection whenever a contractor installs system control units, notification appliance circuit power extenders, and supervising station transmitting equipment in areas not continuously occupied. This requirement intends to increase the probability of transmitting an alarm signal throughout the building and to a supervising station prior to that equipment becoming disabled due to a fire condition.
If the system will use smoke detectors, chapter 17 provides the spacing of these devices based on the selected detector type along with each device’s application. Chapter 18 defines the audibility requirements for all non-voice notification appliances, which will, in turn, define for the system designer the number of each type of appliance and their location. Depending on the local jurisdiction requirements for summoning aid, chapter 26 provides the requirements for the off-premises connections to accomplish that purpose. Additionally, chapters 21 and 23 help the designer determine the best way to include fire safety functions and generally meet the requirements for a building fire alarm system.
Each of these chapters also includes requirements that the installer must follow to ensure a code-compliant fire alarm system. For example, Chapter 23 and Chapter 12 and related sections of Annex A cover the wiring of the system based on class. Chapter 7 requires the installer to provide accurate system documentation to properly represent the system installation. This documentation must provide all system details, installation drawings, and must include battery calculations and voltage drop calculations.
NFPA 72 has a great deal of information for both the designer and installer of fire alarm systems. Avoid the mistake of only reading one or two chapters and assuming you know how to design and install a code-compliant fire alarm system.
WAYNE D. MOORE is vice president at Jensen Hughes.