Alternate Power Source for Fire Pumps - Mandatory?

[ContractorDave]

I was under the impression that an alternate power supply such as a back up generator was mandatory for electric drive fire pumps. Reading NFPA 20, 2007 ed, 9.3.1 "Except for an arrangement described in 9.3.6, at least one alternate source of power shall be provided when the height of the structure is beyond the pumping capacity of the fire department apparatus."

First of all this seems to suggest alternate power supplies are sometimes optional.

And second of all, could someone please educate me on the relevance of 9.3.6 to 9.3.1?

Dave

 

[LCREP]

If the power source is not reliable then a generator is required, other wise it is NOT required. Look at 9.3.2 and A 9.3.2 defines what a reliable power source is. Also the IBC will require a back up power supply if you have a life hazard and a high rise building.

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[LCREP]

Oops I met life hazard OR high rise building.

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[LCREP]

Regarding section 9.3.1 has a typo that was corrected it should reference section 9.3.3 NOT 9.3.6.

Here is the same section from the 2010 edition

9.3 Alternate Power.

9.3.1 Except for an arrangement described in 9.3.3, at least
one alternate source of power shall be provided where the
height of the structure is beyond the pumping capacity of the fire department apparatus

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[ContractorDave]

Good catch LCREP

 

[SprinklerDesigner2]

From my experience most of the time an alternate power source has been optional but the call was always made by the local fire official.

Regarding high rise buildings I've only done one that fit the definition of "high rise" in my life and that was a seven story building that barely made it. We used a generator and automatic transfer switch on that project.

Savannah, Georgia requires alternate sources of power 100% of the time on all fire pumps without exception. Reasons are two fold; hurricanes can interrupt power. A huge percentage of Savannah's income is from tourism and a large number of buildings predate the civil war and I cringe thinking about fire roaring through 200 plus year old attics taking the entire historic district out. Also got to watch where you dig under some streets there's long forgotten cemeteries.

Installing sprinklers at an old school, where General W.T. Sherman had his headquarters, a fitter I work with discovered a long forgotten solid brass bell still hanging in the bell tower that had been closed since the civil war. It's dated in the 1760's (I forget the exact date) and weighs around 300 lbs. It's now in a museum. I love old jobs like this it kind of makes you feel like Indiana Jones.

 

[chicopee]

Insurance companies may ask for two sources of power if electrical power is deemed unreliable. Ask your fire underwriter for an opinion.

 

[stookeyfpe]

The only time it is prescribed in the US (International Building Code) is for high-rise buildings. In these cases, it must be designed for emergency power service. Note that if your fire pump uses an electric driver, NFPA 20 requires the generator have a minimum fuel supply to satisfy an 8 hour service demand under emergency power.