Reliable stationary fire pumps
Volume 23, No. 3
Back in the January-February issue I discussed the changes in the 2007 version of NFPA 20 Standard for the Installation of Stationary Fire Pumps that could affect emergency responders. That article spelled out the requirements of NFPA 20 in regard to emergency responders being able to access the fire pump room in an emergency. This article is intended to get into some of the nuts and bolts of ensuring that the fire pump will operate during the course of a fire and be considered a reliable source of water. This article applies to electric motor driven fire pumps as diesel engine driven fire pumps will be discussed during the next issue. The intent of this article is to generate some thoughts around the proper assessment of electric motor driven fire pumps and their power supplies.
When pre-planning a fire pump room there are three areas that need attention, first is access, can you gain access to the pump in an emergency situation? This was covered in the early mentioned article. It should be noted that electric motor driven fire pump rooms are not required to be sprinklered per NFPA 20. The second portion is the power supply itself, does it meet the necessary code requirements to be considered reliable? The last thing that needs to be considered is the controller/automatic transfer switch, especially where it's located and if it's reliable.
Chapter 9 of NFPA 20 spells out the acceptable power supply arrangements for electric motor driven stationary fire pumps. Some local jurisdictions have specific requirements as well, particularly in regards to high-rise buildings.
Basically, to meet the intent of NFPA 20 and guarantee reliable electric power to the pump driver, there are a couple ways this can be accomplished, depending on your particular situation. It would be a good idea to ask for an electrical one-line diagram of the power supply. Have the building engineer go over it with you.
One means of supply power is to have a dedicated source directly from the municipal provider. This would mean that it has to be protected from fire and other exposures. In some cases it may have to be encased in concrete with the idea being that it has a 2 hour exposure resistance. The exact specifications for this reside in NFPA 70, The Electrical Code. Also, some power supply cabling has been approved for this use as well.
The important part of this power supply arrangement is the exact routing of the cabling as it could pass through the building which the fire pump/sprinkler systems protect. This could be detrimental to the fire pump if the sprinklers didn't activate and the building structure collapsed therefore interrupting power to the pump when it needs it the most. The problem is compounded if emergency responders are in the building. Keep in mind that some facilities do manufacture their own power and if the supply leads meet the standard, this is considered adequate as well.
Another power supply arrangement would be what is typically referred to as the campus arrangement where you have electrical feeds going to multiple buildings. This arrangement, and in the case where you cannot meet the dedicated power supply requirements, requires back-up emergency power supplies. Back-up emergency power supplies are also required when you have a building whose height is greater than the pumping capabilities of the fire department apparatus.
One word of caution when dealing with the back-up power supplies is that you need to make sure that the generator has the capability of operating the fire pump under full load while operating the other emergency building features. The back-up power source typically supports the fire alarm system, the HVAC smoke removal system and emergency lighting. The generator is required to have enough fuel to operate more than eight hours.
Also, be aware of the location of the ATS (Automatic Transfer Switch). NFPA 20 requires it to be located in the pump room. However, it's not always located there. The location of this switch is important because if it fails to operate automatically, it can be operated manually.
All the above mentioned items should be part of the fire department or emergency response team's pre-emergency plan.
Jeffrey R. Roberts, CFPS, is with XL GAPs. Contact him at firstname.lastname@example.org or at (504) 220-0057