What is the Interfacing Equipment in a Fire Alarm System?

Greetings Douglas,

Per NFPA 72 (2019 Ed.) Chapter 14.4.4, what is interface equipment? Is it every system that reports a trouble, supervisory, or alarm signal? Wet/dry chem/clean agent/sprinkler/elevator recall/fire pump/etc. systems?

Thank you, CM

Sometimes, to understand what is meant in the legal-ease of the fire alarm code, we have to look at the meaning from another point of view: a fire alarm system is a Fire Detection and Alarm System (FDAS). Because the FDAS detects fires, it also does things like controlling smoke, capturing elevators, calling the fire department, and sometimes it suppresses fires. This is a holistic view of what a fire alarm system does.

The National Fire Protection Association (NFPA) isn't saying that the fire alarm system includes only the equipment provided by the fire alarm control panel's manufacturer; the NFPA is saying that the Fire Detection and Alarm System includes everything fire related that can initiate an alarm or supervisory. It also includes everything fire related that notifies people, controls smoke, calls the fire department for help, and suppresses fire.

If it's connected to the fire alarm system, it actually is part of the system that detects fire and sounds the alarm.

Interface Equipment

Much of the interface equipment is installed by others, like the elevators, the sprinkler system, the kitchen's range hood suppression and gas shunt, the HVAC air handlers and smoke dampers, etc. It isn't directly installed, maintained, or serviced by the fire alarm company, but the bottom line is that someone has to take some responsibility for the entire Fire Detection and Alarm System.

See:

When a New Air Diffuser is Installed, Why is the Fire Alarm Company at Fault?

That requirement by the state fire marshal seems to be a little extreme. However, even though other vendors install, maintain, and test peripherical fire alarm equipment like elevators, HVAC, sprinklers, smoke evacuation, etc., the NFPA is saying that someone has to be responsible for the whole Fire Detection and Alarm System.

In other words, the NFPA wants someone to oversee and make sure the Fire Detection and Alarm System, as a whole, will work.

The companies installing, maintaining, and testing the interface equipment to the fire alarm system have their own requirements to make sure their systems work. However, none of them really is qualified to oversee the whole Fire Detection and Alarm System.

The people installing the central fire alarm system are the most qualified to coordinate all the separate systems together. It's the fire alarm people, being the most qualified, that are the ones picked to be in charge.

Yes, if the interface equipment can send alarms, supervisory signals, and trouble signals, it is part of the fire alarm system. Yes, if the interface equipment does things because the fire alarm system is sending signals, it is part of the fire alarm system.

Bottom Line: If the interface equipment is connected to the fire alarm system, then it really is part of the overall Fire Detection and Alarm System.

Douglas Krantz

Mr. Krantz

Thank you for the response. We are trying to determine what needs to happen with interface equipment during the annual fire alarm inspection. Our current interpretation is that we need to exercise all of the components that send signals to the FACP and all output components sent by the FACP. This does not mean each interface system needs to be inspected and tested to their appropriate code during the annual fire alarm inspection, but the modules/relays/solenoids do.

The thought is that if we do not test these interface signals during the annual inspection, how do we report on the functionality of these items? The hood or sprinkler contractor does not have access to the annual fire alarm inspection report. We would not want to send alarm technicians multiple times a year to capture interface equipment signals, based on their ITM [Inspect Test Maintain] schedule.

For some interface equipment ITM, we do schedule them in conjunction with the annual fire alarm inspection, elevators for example.

Thank you, C M

To research my response, I used the National Fire Alarm Code Handbook. The information on the interface equipment isn't in the Table of Contents, but it is in the Index.

The Handbook has the legal-ease line-by-line NFPA 72 Code, the Annex A (Appendix) of each line-by-line NFPA Code, and the reasoning behind the Code and the Annex, written by the authors. In some places, it even has drawings and pictures. All of these are grouped together in the Handbook, so all is understood together. This provides a much higher understanding of the NFPA 72 Code than can be gleaned from just the NFPA 72 Code book by itself.

The NFPA sells the Handbooks on their website, right along with the Codebooks. Most people get the Codebooks by themselves because they're less expensive. I get the Handbooks because, even though the Handbooks cost a little more, the extra cost is more than made up for with the extra understanding.

Testing the Interface Equipment

According to the NFPA Code, as explained in the Handbook, if testing of the Interfacing Equipment can't be done directly, the interface equipment may be tested by simulating an alarm. The requirement with that is that the simulation be documented showing both the method and who did the simulating.

Bottom line, though, I really recommend the Handbook because of the greater understanding it provides.



Douglas Krantz