Fire Focus: Interfacing Fire Alarm Systems

When placing a new fire alarm system in an educational facility, a contractor may feel frustrated by the requirement to interface nonfire systems. The fire alarm system (FAS) must either monitor or control these nonfire systems. In many such situations, the FAS designer will not have thought through the interface for each nonfire system. The designer leaves it to the contractor to figure it out.

NFPA 72-2010, the National Fire Alarm and Signaling Code, provides guidance for these systems. The contractor should become familiar with the new Chapter 21 of NFPA 72-2010, Emergency Control Functions and Interfaces.

The electronically locked door is one interface especially important for security purposes. Also, with lockdowns in schools, colleges and universities, and the importance of incorporating fire and life safety features into the lockdown portion of the master security plan, conflicting interface instructions may exist.

Where a building has the FAS protection, NFPA 72-2010 requires that any device used to electronically lock a door in the direction of egress must connect to the FAS. The required unlocking function must occur prior to, or concurrent with, actuation of any public-mode notification appliances in the area(s) served by the normally locked egress doors. Further, all doors required to be unlocked by the FAS must remain unlocked until an authorized person resets the status of the FAS control unit. Examples of doors normally kept closed and locked include those doors opening into a stair enclosure or doors in the horizontal egress (exit) pathway leading from the building.

Additional and related requirements are in the building code and Life Safety Code (LSC). The LSC has the same unlocking requirements, but it does not allow the actuation of a manual fire alarm to initiate the unlocking system.

Where the locked doors could isolate a person, such as in an elevator lobby, the LSC requires a two-way communication system for contact between the elevator lobby and a central control point, constantly staffed by personnel who have received training and who are authorized to provide emergency assistance.

Additionally, NFPA 72-2010 requires, where batteries serve as the secondary power supply, the system design may not use batteries to maintain the doors in a locked condition unless the fire alarm control unit has circuitry and sufficient secondary power to ensure the exits will unlock within 10 minutes of the loss of primary power. The exception to this rule: locks powered by independent power supplies dedicated to lock power and access control functions, which will unlock on loss of power, need not comply with the previous requirement.

Other emergency control functions that interface with the fire alarm system include elevator recall for firefighters’ service; elevator shutdown; first responders’ use of elevators; elevators for occupant-controlled evacuation; shut-down or control of heating, ventilating and air conditioning (HVAC) systems; door release service; exit marking audible notification systems; and fire extinguisher electronic monitoring devices and systems.

The professional contractor must ensure the nonfire system interfaces operate properly during an emergency.

NFPA 72-2010 requires that the performance of any automatic emergency control functions must not interfere with power for lighting or for operating elevators, nor preclude the combination of fire alarm services with other services requiring monitoring of operations. The code also requires that the emergency control functions not interfere with other operations of the FAS.

The connections to all emergency control functions also require specific attention. For example, the contractor must locate a listed relay or other listed appliance connected to the FAS used to initiate control of protected premises emergency control functions within 3 feet of the controlled circuit or appliance. The wiring interconnection between the FAS and controlled electrical and mechanical systems must comply with the requirements of NFPA 70-2008, The National Electrical Code. And, the FAS must monitor the integrity of the interconnected wiring.

Most contractors are familiar with elevator recall, elevator power shutdown, door release service and HVAC requirements. Many do not have as much familiarity with exit-marking audible notification systems and fire extinguisher electronic monitoring devices and systems because the code has only covered the requirements for these fire safety functions beginning with the 2007 edition of NFPA 72. The code permits the signals from a fire extinguisher electronic monitoring device or fire extinguisher monitoring system transmitted to a fire alarm system report as supervisory signals. However, the owner or the authority having jurisdiction (AHJ) may want the signals to report as an alarm signal instead of a supervisory signal.

Contractors who install interfaces for these systems should consult with the AHJs before beginning the installation.

Chapter 18 of NFPA 72-2010, Notification Appliances, contains requirements for interconnection to a fire alarm system and also has additional operational requirements for exit marking systems.

The two newest fire safety functions that you may need to interface with the fire alarm system include first responders’ use of elevators and elevators for occupant-controlled evacuation. The most recent building codes and the LSC contain the requirements for when a contractor will need to install these interfaces in a particular building.

NFPA 72-2010 states that “where one or more elevators are specifically designated and marked for use by first responders during fires, the conditions specified in the code for the elevators, associated lobbies, and machine rooms shall be continuously monitored and displayed during any such use.”

The code requires that the following conditions are monitored and displayed: “(1) Availability of main and emergency power to operate the elevator(s), elevator controller(s), and machine room (if provided) ventilation; (2) Status of the elevator(s), including location within the hoistway, direction of travel, position of landing doors, and whether they are occupied; (3) Temperature and presence of smoke in associated lobbies and machine room (if provided).”

As described in Section 18.11 of the code, a “standard emergency services interface” must also display the conditions listed above.

The second new requirement in the updated building codes and the LSC deals with elevators for occupant-controlled evacuation. This new feature for newly constructed buildings comes as a direct result of what was learned from the terrorist attacks on the World Trade Center. Analysis of that event recognized that elevators can play a major role in facilitating prompt occupant evacuation.

When the master evacuation plan for a building intends to use the elevators for evacuation during fires, the elevators must comply with the same provisions as the elevators used by first responders. Additionally, the lobbies of elevators required by other governing codes or standards for use by occupants to evacuate during a fire must have a status indicator complying with NFPA 72-2010, Chapter 18, which displays an illuminated green light and the message, “Elevators available for occupant evacuation.” This status indicator must display while the elevators operate under normal service and while the fire alarm system is in an alarm condition, but before the fire alarm system has initiated Phase I Emergency Recall Operation in accordance with ANSI/ASME A.17.1a/CSA B44a, Safety Code for Elevators and Escalators. As soon as the FAS initiates Phase I or Phase II elevator recall, the status indicator must change to display an illuminated red light and the message, “Elevators out of service, use exit stairs.”

So, in newly constructed buildings, the contractor has many additional systems to deal with when installing a FAS. Often, the electrical contractor does not install many of these systems. Nevertheless at the time of system acceptance, the code requires the verification of the operation of all fire safety emergency control functions by an operational test. This requirement alone puts the burden on the electrical contractor to ensure these fire safety function systems interface properly with the fire alarm system.

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a co-editor of the current National Fire Alarm Code Handbook. Moore is a principal with Hughes Associates Inc. at the Warwick, R.I., office.

About the Author

Wayne D. Moore

Fire/Life Safety Columnist
Wayne D. Moore, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a principal member and past chair of NFPA 72, Chapter 24. Moore is a vice president with JENSEN HUGHES at the Warwick, R.I., office. He c...

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