Designers, contractors and authorities having jurisdiction often misunderstand the term “survivable.” They presume it means the installer has chosen to use either a Class A wiring scheme or has placed the circuits in metal raceway.


NFPA 72 2013, National Fire Alarm and Signaling Code, defines the term “survivability” as “the ability of any conductor, optic fiber, radio carrier, or other means for transmitting system information to remain operational during fire conditions.” (emphasis added)


Survivability means the circuit will perform properly, even when under attack by fire.


Designing a system using a Class A wiring configuration will enable the system to work under a single open or ground fault. That ability makes the design more reliable, but it does not mean the wiring will remain operational during fire conditions.


Installing wiring in metal raceway will help protect the wiring from mechanical damage, but the same is true here: a fire could render this wiring inoperable. However, as you may know, a performance alternative exists that deems a circuit “survivable.” This happens when the contractor places wiring in raceway in a building protected by an automatic sprinkler system that is installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.


Remember that survivability, as the code requires, only applies to specific notification circuits and other control circuits for equipment that must continue operating during a fire condition. Survivability requirements do not apply to detection circuits and do not normally apply to signaling line circuits—unless the signaling line circuit controls notification appliance circuits or other equipment that must continue to operate during a fire condition.


Of course, the survivability requirement would also apply to a signaling line circuit that extends from a master fire alarm control unit to another remote fire alarm control unit from which notification appliance circuits might originate.


The survivability requirement intends to meet the performance goal of ensuring continuity of system operations where the designated critical circuits pass through fire areas other than the one they serve. Survivability will delay possible damage to the circuits from fires in areas other than those served by the circuits. This will increase the likelihood that circuits serving areas remote from the original fire will have the opportunity to operate as intended without compromise from that fire.


The 1999 edition of NFPA 72 established notification-appliance circuit survivability. The code required notification-appliance circuits, and any other circuits necessary for the operation of the notification-appliance circuits, to have protection from the point at which they exit the control unit until the point that they enter the notification zone that they serve.


The methods to meet this requirement in 1999 included the use of a two-hour-rated cable assembly, installing ordinary listed cable in a two-hour-rated shaft or enclosure, or installing the cable in a two-hour-rated stairwell in a building fully protected by automatic sprinklers installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.


Subsequent editions of NFPA 72 revised the survivability requirements to further clarify the technical committee’s intent. For example, in 2002, the revised requirements applied only to systems with audible and visible appliances used for partial evacuation or relocation of occupants. Most commonly, this included high-rise, in-building fire emergency voice/alarm communications systems. Survivability intended to ensure that attack by fire within an evacuation signaling zone will not impair control and operation of the notification appliances outside the evacuation signaling zone.


Therefore, with the requirement for notification appliances to operate in evacuation signaling zones that are not under attack by a fire, contractors had to design and install circuits and equipment that are common to more than one evacuation signaling zone, and these devices had to be installed in such a way that the fire would not disable them. For instance, a contractor should design and install a signaling line circuit used to control notification appliances in multiple evacuation signaling zones so that one fire would not impair the signaling line circuit and render the notification appliances serving more than one evacuation signaling zone inoperative. To do this, the design and installation had to also include connections to power supplies, including remote power supplies.


The options for compliance with the 1999 survivability requirements included installing listed two-hour fire-rated circuit integrity (CI) cable, a two-hour fire-rated cable system (such as Type MI cable), ordinary cable listed for fire alarm use in a two-hour fire-rated enclosure, or ordinary cable listed for fire alarm use in a sprinkler-protected building. In subsequent editions, the NFPA 72 Technical Committee responsible for survivability requirements proceeded to adjust the methods acceptable to meet the circuit survivability requirements with little or no technical justification—alternatively removing and re-adding the allowance for wiring installed in a building protected by automatic sprinklers as an acceptable method of compliance.


The 2010 edition added two new chapters: Chapter 12 and Chapter 24. A separate technical committee developed each chapter.


Chapter 12 had the charge to describe the various levels of survivability but did not require any specific level to be used. In the 2010 edition, this technical committee removed building wiring with automatic sprinkler coverage requirements as a means to comply with the circuit survivability. The committee did not provide any technical justification for this change.


Chapter 12 of NFPA 72 2013 now describes survivability in terms of levels. Level 0 indicates no survivability requirements. Level 1 requires all wiring in metal raceways and installed in buildings that have full protection by an automatic sprinkler system installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems. Level 2 requires the installation of two-hour fire-rated CI cable, of a two-hour fire-rated electrica-circuit-protective system, or of cables in a two-hour fire-rated enclosure or protected area. Or, one can use two-hour performance alternatives approved by the authority having jurisdiction. Level 3 has identical requirements to Level 2 and a provision that the wiring and system installation must take place in a building “fully protected by an automatic sprinkler system in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.”


Chapter 12 does not require survivability. Rather, it describes the intent and various levels of survivability.


Chapter 24, Emergency Communications Systems, prescribes the acceptable levels of survivability—as defined in Chapter 12—necessary to meet the requirements for in-building fire emergency voice/alarm communications systems and mass notification systems stating, “For systems employing relocation or partial evacuation, a Level 2 or Level 3 pathway survivability shall be required.”


The basis for the circuit survivability requirements depended on the availability of two-hour fire-rated cable, called Type CI, that met the requirements of UL 2196. Cables successfully meeting this requirement survive in a fire test of approximately 1,800°F for two hours and remain operational.


On Sept. 12, 2012, Underwriters Laboratories Inc. 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.


“As a result, manufacturers are no longer authorized to place the UL mark or ULC mark on the following products including Circuit Integrity Cable installed in ‘free air’ or ‘in conduit’:


• “UL Classified Fire Resistive Cable (FHJR)


• “UL Listed cable with ‘-CI’ suffix (Circuit Integrity)


• “ULC Listed Fire Resistant Cable-Circuit Integrity Rating (CIR) Cable“


UL’s action placed the industry in a difficult position. As of this writing, no Type CI cable has passed the necessary test. Only recently has a cable installed within electrical metallic tubing (EMT) received a listing based on the requirements of UL 2196. Furthermore, the cable listed for installation within EMT requires the use of a specific brand of EMT.


Given the turmoil in the market over conflicting code issues and UL’s action, fire protection engineers and designers must apply a ­performance-based approach to help ensure the integrity of the wiring serving the speaker circuits in fire alarm systems. The performance-based approach uses the requirements essentially called for in a Level 1 survivability scenario: all cable in raceway (for mechanical protection) installed in a building protected by automatic sprinklers need to be installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.


This use of a performance-based design alternative tries to deal with apparent conflicting information that occurs in both NFPA 72 2010 and NFPA 72 2013 between Chapter 24’s requirements and information found in the annex for Section 23.10.2 for Chapter 23:“One or more of the following means might be considered acceptable to provide a level of survivability consistent with the intent of this requirement:


“(1) Installing a fire alarm system in a fully sprinklered building in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems


“(2) Routing notification appliance circuits separately


“(3) Using short-circuit fault-tolerant signaling line circuits for controlling evacuation signals”


Although the code specifically does not place enforceable requirements in Annex A, the information quoted above points to the continued acceptance of allowing notification appliance circuits installed in a fully sprinklered building as meeting the intent of circuit survivability. As a contractor, you should also understand that this conflict of information arises because one technical committee develops the requirements in chapters 12 and 23 and another develops the requirements in Chapter 24.


As you can see, we cannot really provide support for the assertion that a system is survivable. The lack of listed Type CI cable that made the original requirements acceptable to the fire protection community leaves us hanging. Suffice it to say, to provide proper fire alarm systems in buildings where survivability requirements apply, you must understand the available alternatives and make an informed design choice for every project that you bid. Otherwise, you may face some costly changes.