I have a house built in the 1890s with the original knob and tubing wiring. I'm completely remodeling the bathroom and I want to rewire 3 bedrooms. At first, my plan was to use one circuit per room, but I'm not going to have enough circuits in the existing panel for that.

So my question is, how much can you put on one circuit. I found an article that said 8-10 lights with outlets, but how many outlets should I put on one circuit, figuring these will be bedrooms which could potentially have tvs, stereos lamps, clocks, toys, plugged into them and a bathroom with hairdryers, curling irons, etc plugged into them, plus an exhaust fan and wall heater.

Secondly, when refering to "lights" does that mean bulbs (say one light fixture has two bulbs in it) and is that considering 70 watt bulbs or 40 watt bulbs or what?

colbtech

Ring Main is the answer.

http://www.diydoctor.org.uk/projects/ringmain.htm

tkrussell

If your location is in the USA, colbtech's suggestion will not work as double ended circuits are not allowed in the USA, and probably not Canada either, since they adopt most of the National Electric Code principals and practices.

There are no limits of quantity of outlets on a residential general purpose lighting circuit.The limits of 8 outlets on a 15 amp circuit and 10 on a 20 amp circuit are from requirements for commercial and industrial buildings.These limits however are good guidelines for residential.

But considering, for example , two bedrooms, each with 6-15 amp outlets, both bedrooms can be on one 15 amp circuit. Not to worry about exceeding the quantity of 8 outlets.

Do not forget to have a AC-DC interconnectable smoke detector in each bedroom and one out in the common area on that floor.


Bathrooms have their own code, must have one dedicated 20 amp circuit for the GFI outlet. If this circuit is only for this one bathroom, the lights and fan in that bathroom are allowed to be on that circuit. This circuit must not have any other lights or outlets on it.

The actual load of lamps or fixtures is irrelevant to any calculations for quantity of outlets. If thou you have a circuit to one room that has a large quantity of fixtures, say a den, with 15- 100 watt lamps, the circuit must be designed to handle that load.

If one bedroom was to have a window AC unit, you can have a separate circuit for that unit, and all other outlets in three bedrooms on the general lighting circuit. Or you can have a separate circuit for the outlets in that bedroom for the lights and AC in that bedroom.

Hope this makes sense. Some of this can be difficult to explain since there are so many codes and so many scenarios to make fit to the code.

jdinkel

So, as far as the bathroom goes, you say I can put the lights and outlets on one circuit, so can I also put the fan and wall heater on it too? Should all this stuff be before or after the GFI outlet?

I'll have one light over the shower, so should that for sure be after the GFI outlet, and the others before it? The heater will also be about 3 feet from the shower, so maybe that should also be after the GFI outlet?

By the way, I'm in Kansas.

tkrussell

What size heater? The heat should probably be on it's own circuit also.

Missed that.

Yes the shower light and the outlet need to be GFI, all other lights and fan can be before or not GFI protectd.

GFI protecting the heater is not required, but a very good idea. You must bond the heater to the tub wiring with a #8 copper wire since it is closer than five feet.

jdinkel

thanks! I don't know if I should start a new thread but I have another quick question...

In the breaker panel, I have a few 30 amp breakers. As far as I can tell, all my wiring is #12 and I don't know of anything that would require a beefier circuit (although the wiring may be bigger than #12, I don't really know). Anyway, should I replace these with 20 amp breakers? Is there any reason I would have 30 amp breakers in this old house?

(oh, by the way, yes I said it's all knob and tubing, but they put all new(er) wiring going from the breaker panel to splice into the knob and tubing (somewhere))

tkrussell

There can be no guessing with wire size, best for you to get a wire guage, even if it is a pair of wire strippers that has the gauge built in.

The K&T wiring usually is all #14. And the wiring connected to a 30 amp breaker should be #10.

Shut these 30 amp breakers off to determine what they are feeding. The only circuits that are usually 30 amp are water heaters, AC, cooktops, and sometimes electric heat.