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I'm rewiring my house to eliminate knob and tube wiring on my second story. The panel only has 20 spaces, so I'm trying to be economical.

My upstairs floor plan is a 70 sqft bathroom and 3 bedrooms, total area of the bedrooms is 500 sqft. Each has a wall sconce and a single outlet per room. Bathroom already has a ceiling light/vent/heater on its own 20A circuit, professionally installed.

As far as I can tell, NEC 2017 allows all recepticles and light fixtures in the bathroom other than the light/vent/heater to be on one 20A circuit, which in my case is a single recepticle and a vanity light.

I plan to put all 3 bedrooms and the hall light on two 15A circuits, one for all the light fixtures and one for all the recepticles. That will come out to 4 light fixtures on one 15A circuit and 6 outlets on the other 15A circuit.

Both bedroom breakers will be AFCI and the bathroom breaker will be dual function AFCI/GFCI.

I can't find anything saying otherwise, is it code compliant to wire my upstairs this way, such that all lights except the bathroom light are on one circuit?

  • I would think that a circuit for all the receptacles for three bedrooms on a 20-A circuit with #12 copper wire. But I question having only one receptacle per room. I would thin you'd want one receptacle on each wall. One nice thing about having the lights on a separate circuit from the receptacles is that plugging in a high current appliance like a vacuum cleaner would not dim the lights. On the other hand if you would have to shut off the breaker to change a fixture in one room, then for that time none of the bedrooms would have lights, but how often does that happen? – Jim Stewart Mar 22 at 22:50
  • What about a receptacle or two in the hall. Our house has only one at the kitchen end of an L-shaped hall and I always thought that a properly located receptacle in the far end of the hall would be convenient for vacuuming the bedrooms. Often the receptacles in a bedroom are behind a dresser or a bed. A hall receptacle might allow vacuuming the entire floor without changing the plug. – Jim Stewart Mar 22 at 22:54
  • Each bedroom currently has one recepticle, the plan is to double that to two per room. I thought about a 7th recepticle in the hall, but the hall is about 5 feet long, and the bathroom recepticle is about a foot away from the door, very convenient for vacuuming all the rooms or putting a lamp. – nexus_2006 Mar 22 at 23:19
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    @nexus_2006, a 20A circuit will allow you to consume 20 A from any one outlet, or 10A each from 2, etc. A 15A circuit will allow a total of 15A. Which outlet(s) you pull that current from should not matter. Since the cost difference in wire is minimal I usually would recommend going with 20A on outlet circuits, in case you need it. – Nate S - Reinstate Monica Mar 23 at 0:40
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    If I were wiring my house again, I would use 20A globally. – Sherwood Botsford Mar 23 at 1:26
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That will come out to 4 light fixtures on one 15A circuit and 6 outlets on the other 15A circuit.

I would highly recommend going to 20A on the 6 outlets. It means going from 14 to 12, but you'll be able to run more things off those outlets. You can still install 15A outlets, as they can be used on a 20A circuit. Speaking from experience, you'll regret staying at 15A if you start maxing the circuit out (and it doesn't take much these days)

The lights can all stay on the same circuit at 15A, which will make wiring your switches up cheaper (don't forget to add a neutral in your switches!). Most lights do not draw that much (especially if you go LED).

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    Cool story, none of my upstairs rooms have switches, the wall sconces (which themselves cover old gas pipes) have little switches on the fixtures themselves. So I'll be adding switches near the doors, neutrals too :) – nexus_2006 Mar 23 at 3:03
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Since you're asking about code compliance, Code requires that any point along a wall (except narrow spaces between doors) have a receptacle within 6 feet of it. Currently, your "1 outlet per bedroom" situation is grandfathered, meaning it can stay that way as long as you leave it alone.

However, now that you are adding receptacles, you are not allowed to just put them wherever you please. You must place them in compliance with Code, unless it is not feasible to do so. Hypothetically suppose you have all the drywall off except on the one side that is a 14' reinforced concrete wall. It will be impracticable to put a receptacle anywhere along the 14' wall. But you should come as close as you can, e.g. Place receptacles on the adjacent walls with an eye toward covering everything but that unreachable 2' gap.

The fine points of this are something you work out with your AHJ when you pull the permit.

If you're, um, not pulling a permit, then it's vital the work be dead nuts perfect. You are likely to get nailed at sale time. The AHJ's normal response to unpermitted work is to a) condemn the structure conditional on b) pulling a permit to c) demolish the unpermitted work and d) pull another permit to e) redo it. And it's mid-sale, so you must do it all in a rush: the expensive way. So if he finds obvious, avoidable defects, he immediately thinks "How many other defects aren't I seeing?" You want him going "this work is pristine, shame to rip it out, alright fine".

Some jurisdictions have limits on how many lights can be on a circuit. This is a throwback to the golden-glow age of incandescent bulbs, which could overload a large lighting circuit. It is still relevant if you install fixtures capable of taking incandescent bulbs, e.g. with Edison bases, because some people are unaware or unwilling to do efficient lighting, and will fit incandescent bulbs in fixtures where that is possible. Bulbless LED fixtures solve that. It is also why socketed CFLs exist. LEDs don't need sockets because the light emitter proper will outlive you, the fixture, and/or the house.

On panel spaces, as you are already noticing, too-few panel spaces is stifling. You can rectify that with a 20-space-ish subpanel, which is in the $100 ballpark. At that point you'll have plenty.

If you are limiting sockets to stay under some "sockets per circuit" limit, that doesn't help, because the number of sockets has nothing to do with the current draws of what are plugged into it. Having 1 circuit per 2 bedrooms, the occupants of the 2 bedrooms still plug in exactly the same things as if there were 3 circuits per 2 bedrooms.. The only question is whether they get a nuisance breaker trip.

  • Thank you for the reply. I did pull permits, but they only asked how much drywall I'm removing. When I said I'm fishing all the cable, they stamped it. – nexus_2006 Mar 25 at 16:39
  • Regarding recepticles every 12', is that linear feet around the perimeter, or? What mean is, if I have a room 10' x 12', do I need one in the center of each wall (4)? Or just one in the center of each long wall (2)? – nexus_2006 Mar 25 at 16:42
  • @nexus_2006 Code requires that any point along a wall (except narrow spaces between doors) have a receptacle within 6 feet of it. – Harper - Reinstate Monica Mar 25 at 16:45
  • I guess my question is, does that measurement wrap around corners? – nexus_2006 Mar 25 at 17:26
  • Yes, the reason is UL requires most appliances to have 6' cords. The presumption is that you'll lay the cord along the edge of the wall, not beeline it. So yes, that measurement wraps around corners, but does not cross places that cords should not go, like across doorways or across floor heaters. – Harper - Reinstate Monica Mar 25 at 18:15

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