Fire Pump

[scotthager]

I have a fire pump application that is rather unique and I am curious as to how I should handle the application.

The fire pump is being utilized in a township pump house to help create a higher pressure to fire hydrants for fire fighting and not supplying a sprinkler system. Pressure sensors will be in piping and will tell pumps when to turn on or off to maintain the necessary pressure. 2 seperate pumps are being designed to maintain the town water pressure.

Will I need to size the OCD per the locked rotor current of the fire pump and the other two pumps in that room? Building is being backed up with an emergency generator. Can I size a seperate ATS per locked rotor of fire pump and run rest of building off second ATS sized per motor full load current?

I have never used a fire pump for this application and any advice would be appreciated.

 

[pete m.]

From what you are describing I don't think it would be an application that article 695 even covers. See 695.1(B)(2).

That being said, IMHO, I think you will find your answers in article 430.

Pete

 

[dbuckley]

From what you are describing I don't think it would be an application that article 695 even covers.

Without actually looking up the Article, I'd say that conclusion is probably correct.

What is being installing seems to be a town water distribution pumping system.

The intent of 695 is to try and keep a building fire pumps running while the building itself is on fire, so little things like overload etc are second tier problems compared to the directive that the pumps must keep running. 695 allows one to bypass some of the safety aspects of the NEC in search of the greater good.

I dont think that relaxation would apply to an installation like this one.

Looking at it from the other end, the overall system design should ensure that the system degrades gracefully with failure.