Demand Factors for Equipment

[jobuTupaki]

Good morning, good afternoon, good night (wherever you may be in the world),

I am curious if there is any documentation related to demand factor for any equipment not listed in the codebook, or any mention of what you should do in the case where the equipment is not specified. I know the demand factors for lighting and receptacles are in the codebook for virtually any application, but I am looking for demand factors for equipment. For example, an exhaust fan, an x-ray machine, AC unit, special purpose refrigerator/etc.

Basically, I am doing a service calculation for an estimate and for equipment, I am stuck on what to put for demand factor and would like to have some sort of theory behind my values.


Currently, I am using max operational load (kVA) = equipment kVA*demand factor

 

[CutToTheChase]

My assumption on equipment has always been if it's not specifically listed in one of the NEC demand factor tables, it's taken at 100%.

So yes, when you put (24) EV chargers in there's no de-rating. This pushes your switchgear square footage up, which forces a relocation to the other side of the building, which creates voltage drop issues, which warrants upsizing every feeder, which increastes the electrical install cost enough you could've afforded a small house with that dime.

(no, I'm not still bitter about it )

 

[jobuTupaki]

I am now even wondering if I need to incorporate demand factors in my load estimate. It appears in the codebook examples, demand factor is not taken into consideration for equipment (only used for recep's and lighting). It is hard to pinpoint as most of the examples are dwelling and there is not an example specific to my application.

 

[electrofelon]

I always tell people that their really aren't that many demand factors in the NEC.

 

[jobuTupaki]

I always tell people that their really aren't that many demand factors in the NEC.

That is what I have found too. I may do without it, unless it is required in the codebook