Calculated Receptacle/Lighting Oulet Loads?

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ritelec

ritelec

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Jersey
Hello,

All these yrs....never really knew the answer.

In laying out receptacle/lighting loads in a residence, I've always laid out receptacles @ 180va (220.14(I)). and lighting outlets I would wing it at the same.

Except for 220.14(D)..(which states if it's a known luminaire)... where might it be mentioned what a lighting outlet has to be calculated at ?

Thank you
 
ritelec said:
Hello,

All these yrs....never really knew the answer.

In laying out receptacle/lighting loads in a residence, I've always laid out receptacles @ 180va (220.14(I)). and lighting outlets I would wing it at the same.

Except for 220.14(D)..(which states if it's a known luminaire)... where might it be mentioned what a lighting outlet has to be calculated at ?

Thank you
Click to expand...

But read carefully, 220.14(I) starts off with "Except as covered in 220.14(J) and (K)"

and 220.14(J) says:
In one-family, two-family, and multifamily dwellings and in guest rooms or guest suites of hotels and motels, the outlets specified in (J)(1), (J)(2), and (J)(3) are included in the general lighting load calculations of 220.12. No additional load calculations shall be required for such outlets. (1) All general-use receptacle outlets of 20-ampere rating or less, including receptacles connected to the circuits in 210.11(C)(3)
(2) The receptacle outlets specified in 210.52(E) and (G)
(3) The lighting outlets specified in 210.70(A) and (B)
Click to expand...

No assigned load per outlet is required for dwellings because of this. Sometimes you may want to consider what the expected load may be for your own design purposes though.
 
ritelec said:
Thank you............so if I have a 20x20 room that general lighting outlet @ 3va has to be rated for 1200 watts...??? :D
Click to expand...

I did not look at the annex, but in general that 20x20 area needs 1200 VA of service or feeder capacity for general lighting, and if that area includes outlets not included in the general lighting calculation, such as laundry or small appliance branch cirucits, then you must add those outlets to the total.
 
kwired said:
I did not look at the annex, but in general that 20x20 area needs 1200 VA of service or feeder capacity for general lighting, and if that area includes outlets not included in the general lighting calculation, such as laundry or small appliance branch cirucits, then you must add those outlets to the total.
Click to expand...

Yeppers.:thumbsup:
 
ritelec said:
Thank you............so if I have a 20x20 room that general lighting outlet @ 3va has to be rated for 1200 watts...??? :D
Click to expand...

No inspector I've seen goes through to check room by room to make sure you got the proper square footage on it. It is done at the total square footage of the dwelling, minus the things that don't count such as garages and open porches, to determine the overall general lighting load. This will tell you how many circuits you need (e.g. a 2400 sq ft house would need 7200W of general lighting/receptacle circuits. That would be either 3 20A circuits or 4 15A circuits) . Those circuits are supposed to be evenly apportioned throughout the house, but that is a rather nebulous requirement. I think the intent is that you NOT put a circuit in one room, a circuit in another room, and run the rest of the house on one more lighting circuit.
 
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suemarkp said:
No inspector I've seen goes through to check room by room to make sure you got the proper square footage on it. It is done at the total square footage of the dwelling, minus the things that don't count such as garages and open porches, to determine the overall general lighting load. This will tell you how many circuits you need (e.g. a 2400 sq ft house would need 7200W of general lighting/receptacle circuits. That would be either 3 20A circuits or 4 15A circuits) . Those circuits are supposed to be evenly apportioned throughout the house, but that is a rather nebulous requirement. I think the intent is that you NOT put a circuit in one room, a circuit in another room, and run the rest of the house on one more lighting circuit.
Click to expand...
Well, if the two rooms are grow rooms and the rest of the house is not going to be occupied, that design makes sense. Could be a factor in Colorado or Washington these days. :)
 
Sorry guys...........maybe I asked the question wrong.......
Not in calculating the va but the actual layout..

180 va........ thats an amp and a half for a (one) receptacle...........3 amps for 2 receptacles......

15 amp circ...

3(2)-6(4)-9(6)-12(8)-15(10)................10 receptacles placed around the room on a 15 amp circ.

3-6-9-12-15...............10 more receptacles placed around room(rooms) on another 15 amp circ...

Oh, there's a lighting outlet on the ceiling............180va?........1.5 amps?
I'm asking what to rate that lighting outlet for in an actual layout if the fixture is unknown.......?

Thank you
 
For residential, you can have as many receptacles as you want on a circuit, they do not count as 180VA each. For light fixtures, you do need to limit them to their maximum rated value. That is, if a can light can take a 100W max lamp, you can have 18 of them on a circuit regardless of how small of a lamp you use in it.
 
suemarkp said:
For residential, you can have as many receptacles as you want on a circuit, they do not count as 180VA each. For light fixtures, you do need to limit them to their maximum rated value. That is, if a can light can take a 100W max lamp, you can have 18 of them on a circuit regardless of how small of a lamp you use in it.
Click to expand...


I'm doing some knob and tube replacement.....
So all though a person probably wouldn't, (except for a few dining room recepts and ac's), all the recpts and single light outlets (not dwn/can/hh) for fixture or fan/light are bed, hall, etc....

You're saying I could put "all" these 26 recepts and 12 light outlets on one circ?

Thats great news.........gonna be saving some $$$ on afci's....
 
suemarkp said:
For residential, you can have as many receptacles as you want on a circuit, they do not count as 180VA each. For light fixtures, you do need to limit them to their maximum rated value. That is, if a can light can take a 100W max lamp, you can have 18 of them on a circuit regardless of how small of a lamp you use in it.
Click to expand...

Still getting my head around this...........except for the required laundry, kitchen etc...

You're saying if I'm wiring a house the size of Michigan Stadium I would only need one 15 amp (convenience) receptacle circuit???
 
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