Define NFPA 72-2016 changes

NFPA 72: National Fire Alarm and Signaling Code has undergone a lot of updates. Here’s a look at the 2016 edition.

By Raymond Grill, PE, FSFPE; and Richard J. Petrey, EIT, Arup July 20, 2016

Learning objectives:

  • Recall NFPA 72: National Fire Alarm and Signaling Code and its basic intent.
  • Discover changes in the 2016 edition of NFPA 72.
  • Apply updated code information into building design.

NFPA has issued the latest version of NFPA 72: National Fire Alarm and Signaling Code in the 2016 edition. The goal of the revision process is to provide NFPA 72 users with rules that both comprehensively and accurately reflect the field of fire alarm design, installation, inspection, testing, and maintenance.

It is imperative to remain up to date with changes to the code, because they take into account advances in technology as well as address any issues that may have needed adjustment from the previous version of the code. Review the latest edition of the code for the complete picture of the changes.

Chapter 7: documentation

The minimum required fire alarm system documentation in the code has been expanded in the 2016 edition. By expanding the amount of documentation that is required, a more complete picture of the fire alarm system can be recorded. The following additional information is now required by either the authority having jurisdiction or where required by code:

  • Room-use identification. Providing the room use will help clarify any assumptions made during the design process regarding how a space is being purposed. This will help ensure that the proper layout of fire alarm devices is being applied to the intended occupancy of the space.
  • Building features that will affect the placement of initiating devices and notification appliances. In select cases, building features will cause fire alarm devices to be placed in a way that seems odd. By documenting these features, it will help clarify why devices have been laid out a certain way.
  • Mounting-height elevation for wall-mounted devices and appliances. Providing this design criterion will allow a review for and facilitate code compliance of the installation.
  • Where occupant notification is required, minimum sound pressure levels that must be produced by the audible notification appliances in applicable covered areas. This will ensure that the notification appliances are providing adequate coverage of the spaces in which they are installed.
  • Pathway diagrams between the control unit, supervising station, and shared communications equipment. This will provide an overall picture of the system and how it communicates.
  • For software-based systems, a copy of site-specific software including specific instructions on how to obtain the means of system and software access (password). Providing these instructions will allow access to the fire alarm system by the owners to facilitate maintenance and future modifications if required.

During the design phase, certain assumptions and decisions are made regarding the spaces for which the system is being designed. The additional documentation is intended to facilitate the plan review process and to minimize the potential for misinterpretation during construction. It also should enhance the site inspection and acceptance testing process.

Chapter 12: circuits and pathways

The 2016 edition of the code modified the language allowing a performance approach for providing survivability. The specific hourly rating for the performance alternative was deleted, and annex material was added to explain the rationale and to provide some examples that could be considered. There are situations where a non-fire-rated or 1-hour fire-rated building may use partial evacuation. That would be one example where providing 2-hour fire-rated cable or 2-hour-rated enclosures for circuits and equipment may not be appropriate. Some specific exceptions have been added. Those will be reviewed in the changes to Chapter 24.

Another change to this chapter is the addition of a new class of circuit. The new Class N circuit has been added to specifically address the use of modern network infrastructure in fire alarm and emergency communication systems. Class N circuits have the following performance requirements:

  • Class N circuits shall include two or more pathways where operational capability of the primary pathway and a redundant pathway to each device shall be verified through end-to-end communication. When only one device is being served, only one pathway is required.
  • A loss of intended communications between endpoints shall be annunciated as a trouble signal.
  • A single open, ground, short, or combination of faults on one pathway shall not affect any other pathway.
  • Conditions that affect the operation of the primary pathway(s) and redundant pathway(s) shall be annunciated as a trouble signal when the system’s minimal operational requirements cannot be met.
  • Primary and redundant pathways shall not be permitted to share traffic over the same physical segment.

A large amount of explanatory material, including sample block diagrams containing Class N circuits, has been added to Appendix A. Refer to this explanatory material to obtain a better understanding of the intent of the code regarding the new Class N circuit.

Chapter 14: inspections and testing

Previously, the code did not cover the recall of a specific piece of equipment by a manufacturer. Provisions for a recall event have been added in the 2016 edition of the code. If a recall program is initiated by a fire alarm manufacturer, the system owner or the system owner’s designated representative is to be notified in writing. This will improve communication with the system owner regarding recalled equipment so the faulty equipment can be replaced in a timely manner.

Another notable change in Chapter 14 is in regard to the inspection and testing of the in-building emergency radio-communication systems. In the 2013 edition of NFPA 72, inspection and testing were to be in accordance with the manufacturer’s published requirements by the local fire department, the building owner, or a designated representative. This has been changed in the 2016 edition of the code.

NFPA 72-2016 now states that the in-building emergency radio communication systems shall be inspected and tested in accordance with the requirements of NFPA 1221: Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems. Although this section has changed, the survivability criteria for these systems has remained in Chapter 24.

Chapter 17: initiating devices

In the 2013 edition of the code, the "total coverage" requirement in Section stated that total coverage included "all rooms, halls, storage areas, basements, attics, lofts, spaces above suspended ceilings, and other subdivisions and accessible spaces, as well as the inside of all closets, elevator shafts, enclosed stairways, dumbwaiter shafts, and chutes." In the 2016 edition, the phrase "as well as the inside of all closets, elevator shafts, enclosed stairways, dumbwaiter shafts, and chutes" has been removed.

Explanatory material has been added in the annex to clarify the requirements when it comes to vertical spaces. While there are certain locations in vertical spaces where initiating devices are required, the overall layout of devices in these areas, including stairways and elevator shafts, can vary greatly depending on their design. For elevator shafts, the explanatory material refers to Section 21.4 for design criteria. For stairways, the explanatory material mentions that the number and location of detection devices will vary based on the design of the stairway. The explanatory material also states that stairways should generally include one smoke detector at the top, but detectors should be located on additional floors to achieve design objective.

It is important to understand that NFPA 72 does not require the installation of fire alarm systems or fire alarm devices. The requirement for a fire alarm system and the specific devices are driven by applicable building and fire codes as well as local ordinances and owners requirements. Once a system and devices are required, then NFPA 72 provides the criteria for design and installation. "Total coverage" as defined in NFPA 72 is not typically required in any of the model building or fire codes.

Chapter 21: emergency control function interfaces

Chapter 21 has undergone some terminology changes in the 2016 edition, and some of the text has been reorganized. An example includes "elevator recall for firefighters’ service" being changed to "elevator phase I emergency recall operation."

Chapter 23: protected-premises fire alarm systems

Section 23.6 regarding the performance of signaling line circuits (SLC) has been expanded in the 2016 edition. The concepts of SLC zones is now addressed in the code. The following are the new requirements regarding SLC zones:

  • A single fault on a pathway shall not cause the loss of devices in more than one zone. This requirement does not apply to circuits connecting transponders.
  • Each floor of a building is expected to be considered a separate zone.
  • If a floor of the building is subdivided into multiple zones by fire or smoke barriers and the fire plan for the protected premises allows relocation of occupants from the zone of origin to another zone on the same floor, each zone on the floor shall be considered a separate zone.
  • The loss of more than one zone shall be permitted based on a documented performance-based approach.

Requirements regarding Class N SLC performance, documentation, and maintenance also have been added to Section 23.6.

Additional language has been added to Chapter 23 to provide guidance on the resetting and the silencing of multiple control units that are interconnected in a network arrangement to protect the same premise. The following requirements have been added to cover these situations:

  • Where multiple control units of the same manufacturer are interconnected in a network arrangement to protect the same premise, the control units shall be arranged to be reset or silenced from one location.
  • Where multiple control units of different manufacturers are interconnected in a network arrangement to protect the same premise, the control units shall be permitted to be reset or silenced individually at each control unit.
  • Resetting procedures shall be documented and posted beside each control unit and annunciator.

Chapter 24: emergency communication systems

Language has been added to Chapter 24 allowing the use of non-listed loudspeakers to achieve intelligibility in a notification zone where listed loudspeakers do not achieve the required intelligibility required by the code. The explanatory language in Annex A states the following additional requirement for using an unlisted loudspeaker: "A failure of a non-listed speaker should not disrupt the operation of listed fire alarm speakers and operation of the fire alarm or mass-notification control equipment. Typically, a dedicated speaker circuit and other audio components, such as amplifiers, could be necessary to meet this functionality."

This new allowance comes from the recognition that in some acoustically challenging areas, listed fire alarm speakers may not be able to produce a message at a level of intelligibility that is desired.

A notable addition to Chapter 24 is the exceptions for pathway survivability of emergency communications systems (ECS). It is important to note that this section is not meant to preclude a performance-based or risk-analysis approach to pathway survivability. The following exceptions have been added:

  • Level 2 or Level 3 pathway survivability shall be required for systems employing relocation/partial evacuation except in the following cases:
    • Level 1 shall be permitted where notification zones are separated by less than 2-hour fire-rated separation.
    • Level 1 shall be permitted where there are at least two pathways that are separated by at least one-third the maximum diagonal of the notification or signaling zones that the pathways are passing through and the pathway is Class X or Class N.

Annex G

Annex G, Guidelines for Emergency Communication Strategies for Buildings and Campuses, has been added as part of the changes to the code. The contents of this section are not required, but are for reference and guidance only. Annex G states: "The purpose of this annex is to provide guidance to system designers, building managers, and/or building emergency personnel responsible for emergency communication on how to create and disseminate messages using basic communication modes."

The information in the annex stems from National Institute of Standards and Technology and Fire Protection Research Foundation research. Annex G is a great place to start in order to determine what information to convey in an emergency message and how to convey it.

Many of the changes mentioned, especially with regards to network-related systems and ECS, provide further guidance on emerging trends and technology in the industry. It is important that fire protection engineers keep up with the evolution of this code and, more generally, all building codes and standards to effectively apply them in future designs.

Raymond Grill is a principal with Arup. He has been a member of NFPA 72 Technical Committees for more than 30 years. He is a member of the Consulting-Specifying Engineer editorial advisory board. Richard J. Petrey is a fire engineer with Arup.