# Commercial generator sizing



## HARRY304E (Sep 15, 2010)

heel600 said:


> I am pricing a generator for a firehouse in my area.
> 
> It has the garage, office, and a firemen's hall with a kitchen in it.
> 
> ...


Lighting in table 220.12.

Heat or A/C not both.





> *
> 
> 220.10(C) Motor Loads.* Outlets for motor loads shall be calculated
> in accordance with the requirements in 430.22, 430.24,
> and 440.6.






> *
> 220.56 Kitchen Equipment* —* Other Than Dwelling
> Unit(s).*
> 
> ...


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## frenchelectrican (Mar 15, 2007)

Heel600.,

Harry is correct on the heat et A/C load you only pick the largest on that but never both.

But for everything else he did hit on the spot of the majorty of the items he posted.

For the vehicle chargers sized them at 100 % load plus any other " shore " power attached to the vehicle. ( you may have to check the specs on them if used the 120 volt shore power plugged to the vehicle )

And don't forget the air compressour they are used with larger firetrucks due they have air brakes on them { few will have air starter as well }.

The other thing is if you going to use the natual gaz you will have to increase the piping / meter size to handle extra fuel flowage. however if you going to use diesel unit make sure you have a fuel tank big enough for minum of 24 hours running time ( check your local codes on this one for on site fuel storage )


Merci,
Marc


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## heel600 (Oct 31, 2007)

HARRY304E said:


> Lighting in table 220.12.
> 
> Heat or A/C not both.



Thank you for your answers

It has one 50 amp (prob 30 amp draw) dishwasher. 220.56 says 100% demand factor

The heat is a furnace with a/c, so the furnace runs (not the gas burners) when the AC runs.

This is going to be a big genny.

Anyone know the codes for this being used as an emergency genny? I heard it has to be up and running in under 10 seconds.

Are there any other requirements?

And before you say "ask the AHJ", they are clueless. Just because they will allow it doesn't make it right. And it should be right.


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## Meadow (Jan 14, 2011)

Did you also factor in the emergency dispatch system and any other electronics? Check to see if they can go through a 10 second outage, if not they may need a UPS. 

Dont be worried about an over sized generator, in an emergency the place could also become a 911 call center or shelter that will have extra equipment plugged in.

Will the unit be gas or diesel?


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## LARMGUY (Aug 22, 2010)

meadow said:


> Did you also factor in the emergency dispatch system and any other electronics? Check to see if they can go through a 10 second outage, if not they may need a UPS.
> 
> Dont be worried about an over sized generator, in an emergency the place could also become a 911 call center or shelter that will have extra equipment plugged in.
> 
> Will the unit be gas or diesel?


Good point about the 911 center.


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## joethemechanic (Sep 21, 2011)

meadow said:


> Did you also factor in the emergency dispatch system and any other electronics? Check to see if they can go through a 10 second outage, if not they may need a UPS.
> 
> Dont be worried about an over sized generator, in an emergency the place could also become a 911 call center or shelter that will have extra equipment plugged in.
> 
> Will the unit be gas or diesel?


If it's your typical small town fire station with a catering hall attached, you can pretty much figure the hall will be used for an evac center/aid station in the event of a serious emergency


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## Dhfisher (May 6, 2011)

The only place I know of where a generator has to be up, running and matched to any other generator is in the hospital business/health care business, the parameters for this will be found in the Joint hospital accredation rulings.

Sent from my iPad using ET Forum


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## [email protected] (Jan 26, 2012)

If it has anything to do with a shelter in place or 911 center then you have some more standards to take in to consideration such as annuciators for the generator.


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## nitro71 (Sep 17, 2009)

meadow said:


> Will the unit be gas or diesel?


My vote is for gas turbine :thumbsup:


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## cabletie (Feb 12, 2011)

Is this really an emergency system or just optional? I would think anything that needed to be on an emergency system would already be on one, like the batteries in the exit lights. If certain items are now being mandated to be on emergency you would need to separate them from the optional system with a separate transfer switch and panel. I would not think that the loss of air-conditioning would pose a threat to human life. If it did they should be somewhere else. But that would have to be determined by someone else not the EC.


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