How Mistakes Are Made
Other codes and their interaction with NFPA 72
NFPA Journal®, March/April 2010
Many installers and code enforcers seem to misinterpret the interaction between the 2010 edition of NFPA 72®, National Fire Alarm and Signaling Code®, and other codes, such as the 2008 edition of NFPA 70®, National Electrical Code® (NEC®), and the 2009 edition of NFPA 101®, Life Safety Code®, as well as the adopted building and fire codes.
I often hear code officials say that a building owner must provide and install a fire alarm system in accordance with “the code,” which many installers assume refers only to NFPA 72. They overlook the fact that they must also consider several other codes to satisfy this requirement.
Actually, all new construction projects must begin with the building code enforced in the jurisdiction. When a governmental legislative body adopts a building code into law, the building code references other codes and standards a building owner must follow. Building codes will require the installation of a fire alarm system for a particular occupancy and specify the extent of detection and notification such a system must provide.
Many installers and enforcers assume that no special requirements are necessary for existing construction and think that a building owner will gladly accept whatever fire alarm system design they choose to use. This could not be further from the truth. Many jurisdictions have adopted a fire code or the Life Safety Code, both of which address fire protection for existing buildings.
In fact, Section 1.2.4 of the 2010 edition of NFPA 72 clearly states that the 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.” This requirement helps ensure that all the actual baseline fire protection requirements come from the particular building code or firecode adopted by law in the jurisdiction.
In addition to the building, fire, and Life Safety Code, fire alarm system installers must also follow the NEC to ensure the proper installation of wiring and electrical equipment. NEC Article 760 provides requirements for the installation of the fire alarm system wiring, while other articles provide requirements for the clearance in front of the fire alarm control unit; the proper installation and support of fire alarm devices, appliances, and cables; and the amount of wiring permitted in a particular size conduit or raceway, to name just a few of the many pertinent items.
Because at least three codes serve as sources for requirements that apply to fire alarm system installations, installers and enforcers must carefully consider all these requirements for each application.
For example, the Life Safety Code requires that an industrial occupancy’s fire alarm system monitor the fire extinguishing or suppression system and sound an alarm in the building or at a constantly attended location. Heat detectors used to actuate the extinguishing or suppression system must meet the location and spacing requirements of Chapter 17 of the 2010 edition of NFPA 72, which include reducing the spacing if the building has a higher-than-normal ceiling. The wiring that connects the heat detectors to the fire alarm system control unit must meet NEC requirements that specify whether the wiring can run exposed or must be contained in a conduit or raceway. They also include how to support the wiring independent of other conduits or raceways.
Having three code books to review can create confusion, so it’s important that designers, installers, and enforcers know where to look for all the requirements when designing and installing a fire alarm system.
Wayne D. Moore, P.E., FSFPE, is a principal with Hughes Associates and immediate past chair of the NFPA 72 Technical Correlating Committee.