commercial building , massage therapy . the customer bought a spa 120 v 2,100 w i have that figured at 17.5 amps my question is do i apply any aditional factors like % s for nominal usage or should my calculation end at 17.5 ? thank you im learning as i go here
no water its just heat and airWhat is a spa? Is it like a hot tub or bath massage tub? If so, see NEC 680 as it covers those but more for other install requirements (e.g. GFCI, other outlets being a certain distance away from the water's edge, equipotential grid may be needed) than load calc.
A factor for load calculation would be whether this could be a continuous load or not. Is it expected to run under full load continuously for 3 hours or more under normal conditions? If it has a heater, those usually cycle on and off so generally it isn't a continuous load.
Another factor would be if this is the largest motor in the place (a water circulation or massage pump is a motor). This isn't a very big motor, so that 125% largest motor factor won't have much of an effect, but could affect branch circuit sizing.
there is some available power near by so i was just wondering how to calculate the load i think he only plans to use it from time to timeno water its just heat and air
thank you i should have been more specific , i was justtrying to save the guy a few bucks if i could but it looks like i will just go with a new circuit.So is it like a sauna (a box you sit in with heat panels)? We have one of those and it just needs its own 20A circuit. No GFCI, no other issues I can think of. Not a continuous load.
Spa is an overload word -- can mean too many different things.
there we go ! thanks for the infoBecause its nameplate amps are over 80% of a 20A circuit, it will have to be on its own circuit and have a single receptacle outlet. A duplex outlet isn't legal because no load can exceed 80% of the circuit rating when on a multiple outlet branch circuit. 210.23(B)(1) and 210.22.