If you are like most people in the fire alarm industry, you struggle with what is and is not allowed for transmitting fire alarm signals to a supervising station. NFPA 72 has changed a lot in the last few code cycles, so let’s clarify some of those changes.
There has been an effort to sunset the use of digital alarm communicator transmitters (DACTs) in the last few years. The committee decided not to put an end date for their installation on new systems but changed the requirements. By doing so, they made it impractical to install a DACT. DACTs were introduced into NFPA 72 in the early 1980s. It took two or three code cycles to accomplish this due to reliability concerns. A DACT was only intended to connect to copper telephone lines. Today, telephone companies no longer install copper lines; they install fiber-optic lines, if anything at all.
In 2009, AT&T, in a filing with the Federal Communications Commission, stated, “With each passing day, more and more communications services migrate to broadband and IP-based services, leaving the public switched telephone network (PSTN) and plain-old telephone service (POTS) as relics of a bygone era.”
In the 2013 NFPA 72, the Supervising Station Alarm Systems committee made drastic changes to DACT requirements. First, since standby power for fiber optic cables is usually no more than eight hours and is provided in the pedestals on the street, the committee changed the test frequency from once every 24 hours to once every six hours. Second, the committee eliminated the use of two telephone lines.
Now you use one telephone line and one other technology, such as a global system for mobile cellular, IP communications or a mesh radio system. Each of these three technologies can be used as a single communications path, so you don’t need the DACT. An exception allows a second phone line if no other technologies are available at the premises, but I don’t see that being allowed very often.
The committee decided Chapter 26 would become more performance- than prescriptive-based and not include specific equipment categories. The intent is to provide general requirements and allow the use of any technology that meets the requirements. Section 26.3.1, which is about performance-based technologies, provides requirements for single and multiple communications pathways.
If you can meet either the performance-based or prescriptive-based requirements plus the secondary power requirements from Chapter 10, you should be able to use the equipment for transmission. That means you must provide 24 hours of secondary power for all transmitters and shared equipment necessary for signal transmission. An exception to this paragraph 184.108.40.206.1 allows eight hours of secondary power for shared equipment if approved by the authority having jurisdiction and if a risk analysis is performed.
You are not allowed to use voice over internet protocol (VoIP) equipment to transmit commercial fire alarm signals. Because you are transmitting data, not voice, the way VoIP compresses and uncompresses signals will dramatically affect the message being sent. Only the fire alarm and communicator needs to be listed for fire alarm. Other equipment, such as modems, routers and switches, needs to be listed as communications or IT equipment.
In 2013, the International Association of Fire Chiefs successfully proposed changes that would require the supervising station to verify fire alarm signals before dispatching the fire department. The strange part was a requirement for the supervising station to notify the fire department that it was verifying the signal. This was called preverification. The maximum time to verify was 90 seconds.
There is an opt-in requirement, so every jurisdiction does not require this. In 2016, the committee deleted the preverification requirements, but verification is still allowed when required by the fire department.
Another proposal added in 2013 required alarm signals to be transmitted by addressable device or zone identification where required by the fire department. In 2016, this was changed to only require point ID or zone ID, if that is what is sent to the supervising station.
There were changes made to the testing requirements in Chapter 14, Table 220.127.116.11, item 4, for Supervising Station Alarm Systems transmission equipment. Some tests are for all transmission equipment, but, in some cases, testing a DACT is different. There is even a test that states “except for DACTs installed prior to the adoption of the 2013 edition of NFPA 72.” If you test fire alarm systems that transmit signals to a supervising station, brush up on the current testing requirements if your jurisdiction has adopted the 2013 or 2016 NFPA 72.
As you can see, many changes were made to Chapter 26, Supervising Station Alarm Systems. I am sure there will be even more as technology changes.