Sprinkler Age A Publication of the American Fire Sprinkler Association
I woke up this morning to see a story on my newsfeed about a paper shredding comping that caught on fire. I recalled retrofitting the fire pump in that building many years ago, and luckily, the post stated, “[The fire] was placed under control within 20 minutes. All facility employees evacuated prior to [fire department] arrival, and there are no reported injuries.” While we never hope for incidents to test our work, it is a good feeling to know that something you had a hand in protected the lives and safety of the people inside who probably didn’t even know it was there.
Staying on the topic of fire pumps, we will once again be fighting the battle for common-sense electrical requirements when it comes to horsepower ratings on fire pump motors. If you recall from the NFPA Technical Meeting a couple of years ago, the membership voted to base the minimum power required to operate a fire pump at rated speed on 200% of its rated flow. It should be noted that NFPA 20 only permits fire pumps to utilize 150% of their rated flow to supply fire protection systems, so this limit constituted a 33% safety factor! Apparently, that was not enough for some members of the technical committee, as that amendment ultimately failed the committee ballot, and the language was returned to the previous text, which requires a power source capable of operating the pump at rated speed at any flow condition. Before testing laboratories changed their interpretation of this requirement several revision cycles ago, “any flow condition” was interpreted as any flow condition within the design objectives of NFPA 20—150%. Now, “any flow condition” literally means “ANY flow condition,” and NFPA 20—a minimum standard that is intended to provide a reasonable degree of fire protection—requires the electrical components of the pump assembly to be indestructible.
The debate was picked up again for the 2028 edition of NFPA 20, which is currently in the Public Comment stage. At the first draft meeting, a task group was formed to come to a consensus on an appropriate flow rate to determine the power requirements. That task group determined that 220% was the appropriate value. For those asking where the 220% came from, we didn’t play rock, paper, scissors, or filibuster until the clock struck happy hour. There was a concerted effort to provide actual technical substantiation for this value, and I believe the committee’s statement speaks for itself:
This revision provides a maximum flow condition for maximum HP for fire pump drivers. The flow criteria were determined to be the variable most directly related to horsepower. Extrapolating the steepest head capacity curve shape permissible using a second-order polynomial in Figure A.6.2 results in 0% of rated pressure being produced at the 220% flow condition. Beyond this condition, the pump would be of no material value to the systems supplied downstream. Additionally, if the pump is run beyond 220% on the steepest head capacity curve, the pump would become an impediment and begin to restrict the flow.
Unfortunately, this did not sway the naysayers from previous cycles, and the first revision failed ballot by three votes. When a first revision fails the letter ballot, it becomes a committee input for the public comment stage, which leaves the section open for revisions at the public comment stage.
If you are in support of limiting the power requirements to a reasonable flow condition, then we need your help during the public comment stage. Submit a public comment in SUPPORT of Committee Input No. 33. Provide data on the maximum reasonable flow conditions in your area and let the committee know about your struggles connecting an oversized motor to an existing power supply. Even if a revision is not made by the committee at the second draft, an overwhelming number of public comments can sway the vote at the Technical Meeting or force the Standards Council to uphold an appeal against a committee that is indifferent to an overwhelming public consensus. Take part in the standards development process and submit your public comment by navigating to nfpa.org/20next.
ABOUT THE AUTHOR: Kevin Hall, M.Eng., P.E., ET, CWBSP, PMSFPE, is the Director of Engineering for the American Fire Sprinkler Association (AFSA). He is a member of several National Fire Protection Association (NFPA) technical committees responsible for developing the model codes and standards, including, NFPA 1 Fire Code, NFPA 13/13R/13D Installation of Sprinkler Systems, NFPA 20 Installation of Stationary Fire Pumps for Fire Protection, NFPA 25 Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, and NFPA 200 Hanging, Bracing, and Anchorage of Water-Based Fire Protection Systems. He also represents AFSA on numerous UL technical committees responsible for revising and maintaining the product standards used in the sprinkler industry. He is a registered professional engineer in Delaware and Maryland, NICET III certified in water-based system layout, a certified water-based system professional through NFPA, and a professional member of the Society of Fire Protection Engineers (SFPE). He earned his Bachelor of Science and Master of Engineering degrees from the University of Maryland College Park in fire protection engineering. In 2021, he was recognized as one of SFPE’s “5 Under 35” award recipients. Prior to his association and committee work, he worked for Reliance Fire Protection in Baltimore, Maryland as a project manager overseeing projects of various sizes and complexity.