Demand Factor for Conference Room/Stage Power

[mrT15]

Hi,

I have a conference room with a stage area in a university building with a small panel protected with a 3P CB at 100A. The panel feeds a few receptacles for temporary power when people are performing/presenting. Since the panel will only be used occasionally, are there any demand factors per NEC that I can apply? Thanks!

 

[charlie b]

I think probably not. But I do not understand what you would apply a demand factor to. If this is a new installation, and if you have already decided on a 100 amp panel, what are you calculating?

 

[mrT15]

I would like to calculate the load. It is a new installation, and the 100 amp panel would be for new receptacles and other future expansion. I have a feeder panel upstream and I need the current load demand (hopefully factored) to size the upstream panel correctly. I mean, if the receptacles are used once a week or less, then I don't think it should be calculated as a total load. I'm looking to see if there are any demand factors like multiple elevators, or kitchen equipment (220.56).

 

[capybara]

why not count each duplex recep at 180 VA per code since it is a convenience outlet.
Allow for at least one recep to feed a projector at the highest one common, for ex., 1000 VA.
allow for a loud speaker cabinet, maybe another 1000 VA (sorry i dont know typ. loud speaker loads)
future expansion is a pig in a poke, cannot estimate accurately.
or allow 100% expansion on the above total, for ex., as worst case.

 

[Smart $]

As capy' said, just calc receptacles at 180VA per yoke (assuming duplex) for general use receptacles.

If a receptacle has a definite purpose, then calc' it at whatever load that definite purpose is.

If the 100A panel is oversized for that load, no problem. Technically, you'll have to make sure the added load does not overload any feeder panel upstream, all the way back to the service... but there are many out there that will forego the Code required process based on gut feeling. Assuming they pull a permit, the AHJ would have to let them fly it under the radar.