Historic occurrences and their impact on NFPA 72
NFPA Journal®, November/December 2011
Fighting fires in high-rise buildings is difficult, making effective firefighter communications more important than ever.
The 2010 edition of NFPA 72®, National Fire Alarm Code®, includes new requirements to help ensure that communications between first responders and the fire command center work when needed. In this context, it is important to note that NFPA 72 discusses how the systems are to be designed and installed but not when.
NFPA codes such as NFPA 1, Fire Code, have criteria in Annex O that also elaborates on the details required for enhanced systems. Due to the critical nature of the two-way radio communications enhancement systems, I encourage you to thoroughly review these requirements in the 2010 edition of NFPA 72. Almost since the day high-rises were first built, the ability of those operating in the structure to communicate reliably with various command centers and command posts has been problematic.
The traditional form of in-building, two-way communications consists of listed, wired, two-way telephone equipment, which NFPA 72 allows building fire wardens to use during emergencies. The code also permits the use of other signaling and communications to report fires and other emergencies, such as voice call box service, signaling, and communications for guard tour services, as long as they do not interfere with firefighter communications.
In buildings with a two-way telephone communications system, the code requires that at least one phone station or jack be provided at each floor, each notification zone, each elevator cab, elevator lobbies and machine rooms, emergency and standby power rooms, fire pump rooms, areas of refuge, each floor level in enclosed exit stairs, and in any other area required by the authority having jurisdiction (AHJ).
When telephone jacks are provided, NFPA 72 requires at least two portable handsets to be stored at the building fire command center. And because these phones must function during a fire, the installing contractor must meet the pathway survivability requirements of Section 18.104.22.168 for all circuits necessary to operate the phones.
The code also contains requirements for two-way radio communications enhancement systems that allow firefighters to use hand-held radios in a building to communicate with the command center. These are more flexible than fixed-location phones and may replace wired two-way telephone equipment.
NFPA 72 has specific requirements for these radio enhancement systems, including non-interference requirements from other radio services, as outlined by the FCC. In addition, building owners may not install systems that can operate on, or cause interference on, frequencies assigned by the FCC without the coordination and approval of the AHJ.
A licensed radio technician must design and install these systems, coordinating with the contractor installing the fire alarms, when one of these systems replaces wired two-way emergency telephones. The radio system designer must ensure 99 percent floor area coverage for all critical areas. These areas may include the emergency command center, the fire pump room, exit stairs, exit passageways, elevator lobbies, standpipe cabinet locations, sprinkler sectional valve locations, and other areas the AHJ deems critical. The radio system designer must also ensure 90 percent coverage for all general building floor areas.
The alarm contractor must ensure that the fire alarm system can provide automatic supervision for all faults on the radio communications enhancement system, such as signal booster and associated power supply and antenna malfunctions.
This is a complex, long-term problem with no simple, short-term solution. The code’s goal is to provide reliable firefighter communications in all high-rise buildings, and the new radio enhancement systems would appear to help meet that goal.
Wayne D. Moore, P.E., FSFPE, is a principal with Hughes Associates.