By Isaac Papier
The ninth edition of UL 864 is bordering more on revolutionary than evolutionary because of the time lapse since the publication of the Underwriters Laboratories' (UL) eighth edition.
During this interim, three cycles of the National Fire Alarm Code® NFPA 72 were completed in 1999, 2002, and 2007 (the Quincy, MA-based National Fire Protection Association [NFPA] added a year to its normal 3-year cycle and, because the standard was not published until late 2006, it will be designated as the 2007 edition). It has brought about a tremendous amount of redesign in annunciating devices because manufacturers are now allowed to specify operating parameters for their annunciation devices as mechanisms to establish compatibility.
Engineered systems designers, therefore, will be able to determine which devices are compatible with which control units by comparing specifications for regulated Notification Appliance Circuits (NACs) and notification appliances.
Under the ninth edition, the determination of compatibility will require a review of ratings rather than a lengthy and expensive test program by UL. It should be noted that some manufacturers have designated some or all of their NACs as "Special Application." The new compatibility scheme would not be applicable to these circuits. Other changes include:
Time to Alarm. The UL 864 ninth edition also includes a major change in alarm-signal processing time that is driven by newer editions of the National Fire Alarm Code. The 90-second signal processing time for annunciation of an alarm from the time an initiating device is tripped has been reduced to 10 seconds. This change is a reflection of new technology capability, incorporated in the latest generation of alarm equipment.
Standardized Interface. The new edition of UL 864 standardizes the interface between fire-alarm notification appliance circuits and annunciation devices. Under the new scheme, building owners will benefit from having a choice of multiple brands of AV products and the ability to determine compatibility, especially in retrofit situations. With a standardized interface between fire-alarm control and the annunciation devices, the owner gets relief. This was a primary concern when this section of UL 864 was rewritten. But, in order to have this flexibility, the voltage and current ratings of the NACs have to be very clearly defined so that, by comparing ratings, you can establish what is and isn't compatible with a certain control panel.
Expandable Systems. During the life of a building, it may be expanded or remodeled to the extent that additional horns and strobes may be needed for continued code compliance. If the original devices are no longer available, it puts the building owner at a tremendous disadvantage because it often means the entire system needs to be replaced. The changes have strengthened requirements for compatibility between smoke detectors, annunciation devices, and control panels, as well as status display and signal processing time. This flexibility is the result of the standard's complexity that requires lengthy and complicated testing to address in-rush current, steady-state current, and maintaining voltage to operate the strobe and synchronization. To accommodate, UL developed a testing protocol that permitted a device to be rated for all of those parameters. Ultimately, this puts the responsibility directly on the device manufacturers to correctly report product ratings. It also puts pressure on designers and installers to make critical product choices, as their reputations are linked to the correctness of the installed system.
Isaac Papier is vice president, industry relations, at Honeywell Life Safety (www.honeywelllifesafety.com), headquartered in Northford, CT.
