Survivability Revisited

Since 1999, the National Fire Alarm and Signaling Code has required survivability for certain circuits that need to work during a fire. In truth, the code has always required speaker circuits serving emergency voice/alarm communications systems to meet a performance requirement for survivability. 

Since 1999, as the technology changed and presented economical options to designers and installers, technical committees have incorporated changes into the code. Cable manufacturers introduced circuit integrity (Type CI) cable to meet designers’ and installers’ needs for providing survivability to critical circuits in a fire alarm system installation. 

On Sept. 12, 2012, Underwriters Laboratories Inc. (UL) summarily pulled the listings for all Type CI cable and issued this statement: “UL has recently conducted research on a wide array of current products and systems originally certified under UL 2196, Tests for Fire Resistive Cables and ULC-S139, Standard Method of Fire Test for Evaluation of Integrity of Electrical Cables and determined that they no longer consistently achieve a two-hour fire-resistive rating when subjected to the standard Fire Endurance Test of UL2196 or ULC-S139. Consequently, UL and ULC will not be able to offer certification to the current program related to these standards.”

Manufacturers were no longer authorized to place the UL mark or ULC mark on products including Type CI cable installed in “free air” or in conduit, UL-classified fire-resistive cable (FHJR), UL-listed cable with “-CI” suffix and ULC-listed fire-resistant cable-circuit integrity rating (CIR) cable (FHJRC).

UL made the following adjustments to its certification directory regarding electrical circuit protective systems:

Withdrawn Systems: UL has removed from its certification directory the following Electrical Circuit Protective Systems (FHIT) that employ Fire Resistive Cables: Systems 10, 17, 22, 24, 25, 27, 28, 30, 31, 32, 33, 35, 36, and 37.

Systems still current in UL Certification Directory: Electrical Circuit Protective Systems (FHIT) that employ protective materials such as intumescent wraps/coatings wraps, tapes, composite mats, etc., still continue to meet certification and code requirements and include the following: Systems 2, 3, 4, 5, 6, 7, 8, 9, 18, 19, 20, 21, and 34. Note: These products are evaluated to Outline of Investigation for Fire Test for Electrical Circuit Protective Systems (subject 1724) and not UL 2196.”

This action left designers, authorities having jurisdiction (AHJs) and contractors with no cost-effective way to meet the code’s survivability requirements.

UL has finally finished developing the new standards for Type CI cable, both for free air and in raceway, and the code has added further notable changes. As a result of UL’s standards finalization, companies could begin submitting their products for listing. 

Type CI cable can be installed in free air or raceway. However, raceway has become part of the new approval process. Ensure you buy the appropriate raceway to meet the new UL standard, and expect the AHJs to renew their efforts to enforce the code’s survivability requirements.

The NFPA 72 technical committees took action to provide relief and alternatives to meet these requirements. The first change is in Chapter 12 for both Level 2 and 3 survivability requirements, as described in sections 12.4.3 and 12.4.4. In number 4 of both sections, the code permits the use of AHJ-approved performance alternatives.

The annex now gives the user better guidance on what type of performance alternatives might apply: “A performance-
based alternative is needed because it is possible to construct a non-sprinklered, Type V (000) building that employs relocation or partial evacuation (e.g., a single-story ambulatory healthcare occupancy) that would not warrant either a 2-hour fire resistance-rated enclosure or a 2-hour cable. Examples of performance alternatives that might be considered in a design for survivability are a strategic application of Class A, Class X, or Class N segments and also wireless communication pathways.”

Section also provides new exceptions for systems employing relocation or partial evacuation, where the particular installation requires a Level 2 or Level 3 pathway survivability:

“Exception No. 1: Level 1 shall be permitted where notification zones are separated by less than 2-hour fire-rated construction.

“Exception No. 2: 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.”

The goal remains the same: notification appliances must continue to operate normally in evacuation signaling zones that a fire has not attacked. Circuits and equipment common to more than one evacuation signaling zone must be designed and installed so the fire will not disable them. 

The choices for performance alternatives have improved, and you can evaluate which option the AHJ will accept. Know the options available to provide an economical approach to the survivability requirements of the code to win more jobs.

About the Author

Wayne D. Moore

Fire/Life Safety Columnist
Wayne D. Moore, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a principal member and past chair of NFPA 72, Chapter 24. Moore is a vice president with JENSEN HUGHES at the Warwick, R.I., office. He c...

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