How Much is Too Much

Question on how many devices/lights are acceptable on a single circuit in a “normal” residential setting.

Background: This is a new build (2012), and we are on the 2009 NEC around here. House was passed by an electrical inspector, and there are NO design drawings for the electrical system.

There are three circuits in question, all are 15amp breakers with 14/2 wiring.
Circuit one feeds 12 can lights with CFL bulbs and 8 wall outlets in one “bonus room”
Circuit two feeds 8 can lights with CFL bulbs, 10 wall outlets, and 3 bath fan/light combos. Lights and outlets are in two bedrooms
Circuit three feeds 25 can lights with CFL bulbs in all common areas

The rule of thumb I have used for the past 15 years is 8-10 devices on a single circuit. These guys blew apart my rule of thumb, and just kept going. Am I out of line in thinking that these areas could become overloaded, and there should not be this many items on single circuits?

If they are overloaded would not the breakers trip ?

CFLs are about 25% of incandescents on those circuits.

Why concern yourself with the number of devices on a circuit?

I have no idea what a client may choose to plug into his outlets.

I have no idea what they would plug in either, I am just trying to help someone out.

To me, the higher number of devices on a circuit points to a higher chance of overloading a circuit , which results in a breaker continually tripping. which results in a continual mashing of teeth due to frustration because they purchased a new house and now the breaker trips all of the time.

OK Then tell them what you just said.

Why the consternation over a trivial matter?

Well it is not a code inspection. But the code does dictate maximums. It matters not to the code if CFL bulbs are used, or LEDs for that matter… realistically somebody could take them out and screw in older style and higher consumption bulbs. There are maximums code wise, and a reason for it, and it does not change for CFLs or LEDs. Logically if anybody were doing a house, it makes no sense to even wire to the maximum - when working in electrical we never pushed things to the limit - left no room down the road to expand at all.

Having said that, call it out the same as you have always. The interesting question of course is if it had a permit when installed, and if it passed any inspection.

The NEC code does not care believe it or not. A code minimum house is done at 3 va per foot. So assuming a 2000 square foot home, 3x2000=6000/120=50/15=3.3 or 4 15 amp circuits for the whole home. Of course you have your required circuits on top of that like 2 20amps for the kitchen, 1 20amp for the washer and 1 20amp for the baths and any other larage appliances like a dryer or Furnace.

Wouldn’t be too hard to figure where things end and go, so just end it someplace and run a new home run on a new breaker, no big deal just a little time and thinking.

That may be true in Canada but that is not where the OP is from.

The NEC does state that the load for the lighting be based on the largest bulb that can be installed, not what actually is installed.

There could be 1000 receptacles on the circuit and the load might be no higher than if there were only 2 receptacles. Number of receptacles has nothing to do with actual load.

To Robin, unlike the CEC we do not have a limit on the number of devices per circuit.

Is that circuit on AFCI’s?

These guys must really be trying to save money (cheap). No one uses 14 gauge or 15 amp breakers on new construction anymore. At least not in my area.

  • I think I was just bewildered about how cheap someone could be when building a $600k house. I have saved money before when building (“value engineered”), but never anything like this.

  • Yes they were all AFCI breakers.

  • Thank you all for your responses.

It may be a local code amendment. When doing a code minimum house 12 vs 14 comes out to be the same.

How did you figure out what was on each circuit? Do you shut the breakers one at a time and trace the circuit? That would take time and is not part of a home inspection.

Dave I think he is just helping someone

I checked an outlet, and tripped an AFCI breaker from there, and the whole room went dark. So I just checked one breaker at a time.

Read up on it as Jeff has indicated and nice enough to give you a link as well for the subject.