Early on in my career, my strategic plan was to make enough money to support my family and grow the business. I did not think too much about the direction I was headed. As Lewis Carroll wrote, “If you don’t know where you are going, any road will take you there.” But as my career progressed, I realized the importance of staying current with and using the new fire alarm systems technologies as they became available.

However, other responsibilities required my attention, so staying abreast of the latest technologies was difficult. I suspect many of you are in the same position.

In the specific case of fire alarm systems, it’s important to know what changes occur as each new code edition is released. Note that I did not say when the code was adopted. Typically, a new code is not taken up by a jurisdiction until it appears in the adopted building code. (NFPA 72-2025 will not be officially adopted until the 2025 International Building Code takes effect in that jurisdiction.)

The only U.S. exception is California, which typically adopts the most recent edition of NFPA 72 as soon as it is available and has been reviewed by the California State Fire Marshal’s office. 

Trusted fire alarm systems experts know the new code often has the latest installation and application requirements for any new technology. Knowing this enables you to better serve your customers and make more profit on a typical project. If nothing else, knowing the code keeps you from being blindsided by someone either convincing your customer they know a better approach or requiring a change in your installation that precludes you from finishing the project in the time estimated (read: lost profits).

MFVN requirements

For example, a managed facilities-based voice network (MFVN) and its requirements first appeared in the 2010 NFPA 72 because the major telecommunications carriers were eliminating copper circuits. When these circuits were removed, the typical digital alarm communicator transmitter (DACT) would not operate reliably over the replacement fiber circuits. The industry responded with what was commonly called an “IP DACT,” which was a misnomer. Many contractors were forced to make costly, last-minute changes to enable their fire alarm system to provide off-premises connections to a supervising station. As time progressed, we discovered that some IP DACTS were not transmitting the fire alarm, supervisory and trouble signal completely, i.e., some of the “packets” of information were either missed or transmitted incorrectly.

NFPA 72 3.3.172 defines an MFVN as “A physical facilities-based network capable of transmitting real-time signals with formats unchanged that is managed, operated, and maintained by the regulated communications carrier to ensure service quality and reliability from the subscriber location to the supervising station via the public-switched telephone network (PSTN) or interconnection points with other MFVN peer networks.” 

Guidance in Annex A

Annex A provides more guidance with this definition.

The NFPA 72 technical committee found these industry changes difficult to understand, but the ultimate problem was that the code did not apply to telephone company equipment, which is regulated by the state public utilities commission. And unfortunately, all changes made to telephone system infrastructure were accomplished without thought given to ensuring the reliability of fire alarm system off-premises signal transmission or informing the technical committee of the changes.

The technical committee responsible for the Supervisory Systems Chapter in NFPA 72 met with telecom providers to develop requirements for MFVN use. A plethora of equipment has been developed to ensure reliable signal transmissions from the fire alarm control unit to the supervising station. 

Much of this equipment still does not meet the code requirements for effective signal transmission. The MFVN is a telecommunication device that—while UL listed—is not listed to UL864, and so does not come under the authority having jurisdiction’s purview. However, there is equipment on the market that meets all the signal transmission requirements.

I will outline more issues in the code that could affect your fire alarm system installations in future articles.

stock.adobe.com / Arnon Parnnao