5.27.25 – SSI -Shane Clary
This column continues a series reviewing the 2025 edition of NFPA 72, the National Fire Alarm and Signaling Code.
This article is my fourth installment on the new additions to NFPA 72, National Fire Alarm and Signaling Code, 2025 edition. If you missed the first two parts of my review, you can see them here, here and here.
In this article, I will cover chapters 21 and 23.
NFPA 72 Chapter 21: Emergency Control Function Interfaces
The first change is found in 21.2.4.1. A change has been made to the distance that an emergency control function interface may be sited from the equipment that it is intended to trigger. In former editions of NFPA 72, the distance was three feet.
There now is an allowance to increase that distance to 20 feet if the conductors are installed within metal raceway or metal armored cables. In addition, if a Class D circuit is to be used, there are no restrictions as to the distance.
The language on dedicated function alarm control units was modified within 21.3. In a facility that does not have a required building fire alarm system, Elevator Phase I Emergency Recall Operation can be connected to either a nonrequired building fire alarm system or a dedicated function fire alarm control unit.
When a dedicated function fire alarm control unit is to be used for elevator recall, it shall be designated as “elevator recall control and supervisory control unit.” This shall be permanently identified on the control unit.
Chapter 23: Protected Premises Alarm and Signaling Systems
Language was added to the Standard in 23.3.5.2.2 to make it clear that a dedicated function fire alarm system shall not be required to include other features of a required building fire alarm system.
Combination Systems Signaling is addressed in Section 23.8.4.7. Language was added to state that, in a combination system, the fire alarm signals are to be distinctive and clearly recognizable.
Signals from a combination system are to be indicated in a descending order of priority, as follows:
- Signals associated with life safety
- Signals associated with property protection
- Trouble signals associated with life and/or property protection
- All other signals
However, that sequence may be modified where otherwise required by governing laws, codes or standards.
The 2025 edition tightens the requirements for alarm verification. The new requirements are found within Section 23.8.5.4.
The first is that alarm verification is not to be enabled unless there have been nuisance alarms, or it is expected that, due to the environment, there will be nuisance alarms. The enabling of this feature with a fire alarm system shall be protected by either a password or limited access to the system. If alarm verification is to be used, it shall be recorded on the Record of Completion.
Section 23.16 added a number of requirements for low-powered wireless devices that may be part of a fire alarm system. These were both new and reorganized so as to meet the NFPA Manual of Style requirements. A battery-depletion threshold is described as being when a wireless device is no longer capable of providing seven days of trouble signal operation, followed by the signaling of a single non-trouble response.
A low-battery signal is to be transmitted before the device has reached the battery-depletion threshold.
The low-battery signal shall provide the following:
- The signal shall be distinctive from alarm, supervisory, tamper and trouble signals.
- The signal shall visibly identify the affected low-power radio transmitter/transceiver.
- The signal shall automatically re-sound at least once every four hours when silenced.
Trouble signals shall comply with the following:
- Trouble signals shall identify the affected low-power radio transmitter/transceiver at the system control unit.
- Trouble signals shall automatically re-sound at least once every four hours when silenced.
Each wireless transmitter is to service only one device. Thus, two tamper switches on a double backflow prevention valve are to have two separate transmitters.
There is an allowance in which a wireless transmitter may be connected to more than one device. This is when multiple batteries are used within the wireless transmitter.
The batteries for a wireless device are to be capable of operating for not less than one year before the battery-depletion threshold is reached. A catastrophic battery failure shall cause a trouble signal. In addition, any failure of one wireless transmitter shall not affect other low-powered wireless transmitters.
Where multiple batteries are used, each individual battery shall be monitored for the battery-depletion threshold.
In my next article, I will cover Chapters 24 and 26 of the 2025 edition of NFPA 72.
SHANE CLARY, Ph.D., is an SSI Industry Hall of Famer and has more than 45 years of security and fire alarm industry experience. He serves on a number of NFPA technical committees, and is vice president of codes and standards compliance for Concord, Calif.-headquartered Bay Alarm Co. He can be reached at smclary@bayalarm.com.