Table 220.44 Demand factor for non-dwelling receptacles

[cppoly]

Looking at this table, you can take a demand of 50% receptacle VA after the first 10,000 VA, but this doesn't apply to the 1 VA / SF allowed using 220.14(K).

Has anyone else made the MISTAKE of taking a demand when using the 1 VA / SF allowance in office buildings, I mean there's going to be a demand on receptacles no matter what right??

For instance, a 50,000 SF office building building would be 50,000 VA of receptacle load, but you're not allowed to take a demand on this according to 220.44 since it only applies if you actually knew the yoke count, but who ever knows that? This make NO SENSE!!! Why can't we take the first 10,000 VA at 100% and 50% of the remaining VA, which would be 30,000 VA demand load.

 

[cppoly]

Any input?

 

[Dennis Alwon]

I cannot tell you why other than there had to be some documentation for this. It does seem odd if you had a 50,000 sq. ft building with 50 receptacles that you would have to use 50,000va.

 

[Dennis Alwon]

I am assuming that a 50,000 sq.ft building could accommodate a lot more receptacles at later dates so they want the service to cover the worst case scenario

 

[bwat]

Agreed. Just reading through those sections it seems like the 1 VA / SF is treated like a minimum. If someone hands you plans and the design details the receptacles and it goes way past that "minimum" and puts in a ridiculous amount of receptacles, the code wants you to consider the large amount of receptacles, but not at 100% past a certain point (10kVA).

I don't do much work in this arena. So although 50kVA for a building with only 50 receptacles seems high... looking at it the other way: 50kVA for a 50,000 sq. ft building doesn't seem that high to me. Is that accurate?

 

[kwired]

I think the 1VA/SF should apply to the actual office spaces and not to the entire building, but just my opinion. If it weren't for somewhat common use of space heaters at workstations I don't think the demand would need to be that high.

If you have a lobby area that is about 5,000 square feet there is probably pretty low receptacle load in comparison to office spaces and this should not be counted at same load density per square foot. Plus you have restrooms, break rooms, mechanical rooms, etc. that may have completely different load density as well.

 

[Dennis Alwon]

I think the 1VA/SF should apply to the actual office spaces and not to the entire building, but just my opinion. If it weren't for somewhat common use of space heaters at workstations I don't think the demand would need to be that high.

The Table says office buildings. It does not say office areas or spaces so IMO, you must use the entire sq.ft

 

[cppoly]

Thanks so far. Any thoughts on why the code allows you to take a demand if you have 50,000 VA of receptacles going in as compared to NOT being allowed to take a demand of 50,000 receptacle load calculated from 1 VA / SF?

 

[charlie b]

My guess is that any notion of "not everything will be running at the same time," that is, the notion that allows us to use demand factors, was already taken into account when the value of "1 VA/SF" was assigned. Put another way, the "1 VA/SF" has already had the demand factor applied.

 

[kwired]

The Table says office buildings. It does not say office areas or spaces so IMO, you must use the entire sq.ft

Yes it does, I guess I didn't make it clear enough that was my opinion on how it maybe should be. Before you tell me - I'm not submitting a PI, it doesn't really effect me all that much as I don't believe I have ever done any major office complex.