sprinklernotes
Disconnects for Electric Fire Pump Controllers
You asked the following questions: “If installing a disconnect and external overcurrent protection devices for an electric fire pump controllers, first is it allowed and second can they be located inside the fire pump room?” In response to your question, we have reviewed NFPA 20, 2016 edition as the applicable standard. Our informal interpretation is that overcurrent protection is allowed to be installed and, if necessary, can be installed inside the pump room. Section 9.2.3 allows one disconnecting means and associated overcurrent protection device of electric service to the fire pump provided your power supply arrangement complies with Section 9.2.2 and Subsections 1, 2, 3, or 5. The Handbook commentary for Section 9.2.3 states the single upstream disconnect permitted by Section 9.2.3 affords disconnection for activities such as maintenance and is not intended to be operated under fire conditions. Additional disconnecting means would reduce the reliability of the fire pump, since these disconnects can be remote from the fire pump room, typically not easily located makes it difficult to manage especially during a fire event. The intent behind these sections is to make sure the pump will run regardless of any problems during a fire scenario until the pump destroys itself. Fire pumps themselves are sacrificial and are typically only allowed to be stopped to preserve the integrity of the system piping. That said, the approved location of the disconnect will need to be tapped in ahead of the main service building, to avoid any advertent interruption to the fire pump, due to any power shutdown to the building. Now regarding the location of the disconnecting means and associated overcurrent device. The NFPA 20 handbook commentary for Section 9.2.3.1 (3) gives a few examples of acceptable locations. A fire pump disconnect is considered to be remote from disconnects for other non-fire pump loads when it is not within sight of the other disconnects. Means of achieving this include locating the fire pump disconnect in a different room from where the other disconnects are located, or if in the same room, the disconnects are separated by building construction or permanently installed equipment that provides separation, such that all disconnects are not within sight from any location within the room. In closing, if you meet the requirements of Section 9.2.2 and Section 9.2.3 you can use an overcurrent protection device, and it can be located within the same room provided they are separated by building construction or permanently installed equipment that provides separation, such that all disconnects are not within sight from any location within the room.
