When we think of system integration in the electrical and fire alarm systems market, we understand it involves bringing together component subsystems into one larger system and ensuring they function as one. And normally, the integrated system includes a fire alarm.

The combination guard’s tour and fire alarm box constitutes one of the oldest “integrated” systems allowed by almost all editions of NFPA 72, the National Fire Alarm and Signaling Code, and its predecessors. This integrated system includes a manually operated box for separately transmitting a fire alarm signal and a distinctive guard’s patrol tour supervisory signal.

The code addresses field installations that interconnect two or more listed control units, possibly from different manufacturers, to fulfill the code’s requirements. Such an arrangement should preserve the reliability, adequacy and integrity of all alarm, supervisory and trouble signals, and the interconnecting circuits must meet the code requirements. For example, where interconnected control units are in separate buildings, the code advises that the installer must consider protecting the interconnecting wiring from electrical and radio frequency interference.

The code permits a fire alarm system that uses other component systems, in whole or in part, and integrates with a nonfire-signaling system. Examples of nonfire systems that often integrate with fire alarm systems include security, card access control, closed-circuit television, sound reinforcement, background music, paging, sound masking, building automation, and time and attendance systems. A common reason to integrate nonfire systems with a fire alarm system is to ensure the nonfire systems react appropriately when signaled by the fire alarm system.

Although the code permits fire alarm systems to share components, equipment, circuitry and installation wiring with nonfire systems, the code also requires the operation of a nonfire system function originating within a connected nonfire system to not interfere with the required operation of the fire alarm system.

Nonfire alarm systems—such as carbon monoxide (CO) and fire extinguisher monitoring systems—often integrate with the fire alarm system. An example is a fire extinguisher electronic monitoring device or fire extinguisher monitoring system transmitting to a fire alarm system as supervisory signals. CO systems that integrate with a fire alarm system have specific signaling requirements. Typically, signals from CO detectors and CO detection systems transmit to a fire system and specifically annunciate as CO alarm signals. However, these signals may transmit as supervisory signals when the building’s response plan, evacuation plan, fire safety plan or similar documentation indicates this need.

For systems such as CO detection, fire extinguisher electronic monitoring devices, emergency communication (mass notification), or intrusion, much of the benefit of a combination system derives from the ability to use common wiring. If the equipment in the combination system has equivalent quality to fire alarm equipment, and the system monitors the wiring and equipment in the same way as it does for fire alarm equipment, then the code permits wiring to be shared. If the equipment does not possess equivalent quality, the code requires isolating the systems.

The code allows equipment to attach to a fire alarm circuit, either among the fire alarm devices or as a branch or extension of the fire alarm pathways, only when the arrangement meets the following requirements:

• All the equipment and pathways meet the monitoring for integrity requirements of the code.

• All the equipment and pathways receive maintenance from a single service organization.

• A contractor has installed all the equipment and pathways in accordance with the code’s requirements.

• All the equipment has received a listing as compatible with the fire alarm equipment, or the equipment has an interface listed as compatible with the fire alarm equipment.

The 2013 edition of NFPA 72 commonly permits various emergency communication systems, such as fire alarm, mass notification systems (MNSs), firefighter communications, area of refuge communications, elevator communications, or others served through a single control system or through interconnection of several control systems.

Additionally, the code states that, if the equipment connects “to the fire alarm system via separate pathways, then short circuits or open circuits in this equipment, or between this equipment and the fire alarm system pathways, cannot impede or impair the monitoring for integrity of the fire alarm system or prevent alarm, supervisory, or fire safety control signal transmissions.” And, once you connect a nonfire alarm system to a fire alarm system, all of the nonfire alarm equipment grounds—or the grounds between this equipment and the fire alarm system pathways­—must annunciate and receive correction in the same manner as grounds in the fire alarm system.

Specific requirements ensure the reliability of the fire alarm system. Short circuits or open circuits in the nonfire alarm equipment, or between the equipment and the fire alarm system pathways, cannot impede or impair the monitoring for fire alarm system integrity or prevent alarm, supervisory or fire safety control signal transmissions.

And, finally, removal, replacement, failure, maintenance procedures or grounds on the nonfire alarm hardware, software or circuits cannot impair the required fire alarm system operation.

Now, in combination systems, the code requires fire alarm signals to be distinctive, clearly recognizable and able to indicate in descending order of priority, starting with signals associated with life safety, then signals associated with property protection, then all trouble signals associated with life and/or property protection, and, finally, all other signals.

Actual signal priority schedules may vary, depending on the emergency response plan and requirements of the authority having jurisdiction. As most contractors already know, the 2010 edition of the code allowed MNSs to take priority over the fire alarm audible notification message or signal under prescribed conditions designated in the risk analysis and emergency response plan. This allows the MNS to prioritize emergency signals based on the risk to building occupants. The code requires the designer to specify the desired operation, in particular, as to what should occur immediately after the mass notification message has completed. In fact, next to security systems, MNSs probably are the most integrated with fire alarm systems, followed by CO systems.

Coordinating an emergency communications system’s function with other systems that communicate audibly or visibly (such as fire alarm, security and public address systems) is essential to provide effective communication in an emergency situation. Conflicting or competing signals or messages from different systems could confuse occupants and affect occupant response in an undesireable way. Where a building or space has independent signaling systems that use audible or visible notification, the emergency communications system needs to interface with those systems to affect related control actions, such as deactivating both audible and visible notification appliances.

The use of a single integrated combination system may offer both economic and technical advantages. In any case, coordination between system functions is absolutely necessary. The risk analysis for the emergency communications should include an analysis of the coordination of emergency communications systems with other systems. Those performing the risk analysis may use additional documents, such as NEMA Standard SB 40, Communications Systems for Life Safety in Schools, as supplemental resources to provide help with risk assessment and application considerations.

Integrating any of the systems mentioned in this article requires a precise reading and understanding of NFPA 72, the National Fire Alarm and Signaling Code, to determine how the integrated systems and their subcomponents must operate. Additionally, to ensure a profitable project when using integrated systems of different manufacturers, you must thoroughly understand each system’s connection and operational needs before proceeding with the installation. Finally, ensure that a clear set of design documents contains the approved wiring interfaces for all of the integrated systems and that these interconnections will meet the code’s intent and the approval of the authority having jurisdiction before getting started.