Max number of recepts per circuit

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dnem

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NEC 2005 Handbook page 106 has a shaded paragraph to explain Exhibit 220.4 that says, "In Exhibit 220.4, the maximum number of outlets permitted on 15- and 20- ampere branch circuits is 10 and 13 outlets respectively. This restriction does not apply to outlets connected to general lighting or small-appliance branch circuits in dwelling units."

So what is the max for lighting and small appliance ?

Outlets "connected to general lighting" with lighting fixtures attached are "calculated based on the maximum volt-ampere rating of the ... lamps for which the luminaire(s) [fixture(s)] is rated" 220.14(D). So the limit would be based on each fixtures wattage rating.

But what is the max for small appliance ?

220.14 (I) says it doesn't apply to "outlets specified in 210.1(C)(1) & (C)(2)" which is small appliance & laundry but 220.14(L) covers "all others" which I think would include small appliance. (L) says to calculate "based on 180 volt-amperes per oulet", so 180 watt recept at 120 volts is 1.5 amps. A 20 amp small appliance circuit divided by 1.5 amps is 13 recepts.

So is the max 13 on a small appliance circuit or not ?

David
 
I believe these numbers are used for load calculations, but not to actual installations. Circuit performance (the ability of the circuit to supply the load) will dictate receptacle quantities.

I'll typically place only two receptacles on each residential kitchen small-appliance circuit in a "custom" home, where I'm the electrical designer as well as the electrician.

"This restriction does not apply to outlets connected to general lighting or small-appliance branch circuits in dwelling units." That just about covers most residential circuits.
 
So what is the max for lighting and small appliance ?
Click to expand...

The NEC doesn't specify a maximum in residences. Lighting is calculated at the actual wattage connected, and there is no limit to the number of receptacles on small appliance circuits in the NEC. Local jurisdictions, such as NM where I practice, may specify different numbers.

Jim T
 
Thanks Larry

Thanks Larry

I had a suspicion that the info was just for calcs only but that still leaves me with the question, as a electrical inspector for a municipality that has no requirements other than the NEC, what maximum number of recepts can I enforce for:
A) general purpose circuits
B) small appliance circuits

David
 
Reply to Jim

Reply to Jim

Jim,

This had never been an issue before until I hit an inspection where a contractor stuck 4 bedrooms on one AFCI to try to save money. I red tagged the installation and sighted the "180 watt rule" in 220.14(L). But I wondered what would happen if the contractor disputed the call.

Other than this one time, I haven't run across anyone that has tried to push past 10 plugs on a 15 and 13 plugs on a 20.

I'm wondering what I should do if a contractor tries to stick 13 small appliance plugs on a circuit. They could take half the kit counter, the dining room, the dinette, and a few houses even have a big breakfast room. They could load up a small appliance to 13 on a 20.

What would be the proper response for an inspector that has no local code to supplement ?

David
 
Re: Thanks Larry

Re: Thanks Larry

dnem said:
I had a suspicion that the info was just for calcs only but that still leaves me with the question, as a electrical inspector for a municipality that has no requirements other than the NEC, what maximum number of recepts can I enforce for:
A) general purpose circuits
B) small appliance circuits
Click to expand...

A) There is no maximum
B) There is no maximum
 
dnem said:
This had never been an issue before until I hit an inspection where a contractor stuck 4 bedrooms on one AFCI to try to save money. I red tagged the installation and sighted the "180 watt rule" in 220.14(L). But I wondered what would happen if the contractor disputed the call.
Click to expand...

Although that is an extremely poor design, it's code compliant. That code section does not apply to dwelling units. The only load calc that applies to a general purpose circuit in a dwelling unit is 3 VA per square foot.

I'm wondering what I should do if a contractor tries to stick 13 small appliance plugs on a circuit.
Click to expand...

You should do nothing. There is no code that would prevent that from happening. It may be a poor design, then again it might not be. The NEC is not concerned with design issues.

What would be the proper response for an inspector that has no local code to supplement ?
Click to expand...

Enforce the NEC as written.
 
If you are looking for the max # of openings per circut (residential) the NEC does not actually address this.But it does address the sq.ft.area that a circuit may serve regardless of the # of receptacles.If you use 1 circuit /600 sq. ft. then it is code compliant as far as receptacle outlets/ gen. lighting..Dedicated lighting loads will change that.This is unless your area has addendums that are in place.
Now I do agree that 1 afci for 4 bedrooms is streching it but if all bedrooms sq. footage was within the 600 sq. ft. then the install should have been passed.Again this is the max. area that a circuit may protect.Design is a horse of an entirely different color,especially with the advant of 15 amp vacums.Huge entertainment centers etc.
 
David the 180 VA per yoke does not apply to dwelling units at all.

Take a look at 220.3(B)(10)

220.3(B)(10) Dwelling Occupancies.

In one-family, two-family, and multifamily dwellings and in guest rooms of hotels and motels, the outlets specified in (1), (2), and (3) are included in the general lighting load calculations of 220.3(A). 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...

Exhibit 220.4 in the hand book applies to non-dwelling occupancies.
 
David, I agree with Peter, Bob, et al. If you're enforcing the NEC as written, than you were incorrect to violate the guy for having 4 bedrooms on one AFCI. The 180va rule does not apply to dwellings. Design issues aside, his installation was code compliant.
 
The guy with 4 bedrooms on 1 afci is a very cheap contractor.His install is legall but he will be wishing he had done something better when he starts getting calls about it tripping breakers.Also he has increased his problems in troubleshooting when they trip for an afc fault.As an inspector you should know how to pick his job apart if the need is there.The best of electricians mis something on every job.
 
Jim W in Tampa said:
As an inspector you should know how to pick his job apart if the need is there.The best of electricians mis something on every job.
Click to expand...

As much as I hate this method it is generally effective. :evil:

Inspector: I would like you to break up these bedrooms on more circuits.

Contractor: I don't have to.

Inspector: I have to go get my measuring tape and see if all the staples are 4.5 feet or less apart. :wink:
 
iwire said:
Jim W in Tampa said:
As an inspector you should know how to pick his job apart if the need is there.The best of electricians mis something on every job.
Click to expand...

As much as I hate this method it is generally effective. :evil:

Inspector: I would like you to break up these bedrooms on more circuits.

Contractor: I don't have to.

Inspector: I have to go get my measuring tape and see if all the staples are 4.5 feet or less apart. :wink:
Click to expand...

Exactly what i am saying.Oops your staples on this wire are 54 1/2 inches apart,RED TAG.When you have an electrician that wants to be a hard a$$ help him enjoy the game. :)
 
Would NEC section 210.11(B) apply here? It reads in part The load shall be evenly proportioned among multioutlet brach circuits within the panelboard. Does this mean that it is not permissable to have 20 general lighting outlets on one circuit and ten on another?

romeo
 
I would rather have an inspector site me for staples to far apart then for things that are not violations in the first place. I would never put four rooms on a breaker myself. And if I was a inspector I would ? the contractor on the practice of this and I would get out the glasses and look for real problems and site those. And hope the Contractor changes his way or the code changes so the inspector can inforce a violation.
 
romeo said:
Would NEC section 210.11(B) apply here? It reads in part The load shall be evenly proportioned among multioutlet brach circuits within the panelboard. Does this mean that it is not permissable to have 20 general lighting outlets on one circuit and ten on another?
Click to expand...
No, that depends on the load on each receptacle. The evenly-divided rule applies to current load, not quantity. That's why I place only two receptacles on a kitchen circuit; most appliances are high-current loads, such as coffee makers, microwaves, toaster ovens, etc.

Keeping in mind that I usually keep receptacles and lighting circuits separate in most rooms, not just kitchens/dining-rooms, I may put 2 or 3 bedrooms' worth of receptacles on a 20-amp circuit, and the lighting and ceiling fans on a 15-amp circuit, including hall and baths.
 
I always thought that the 3VA per square foot combined with romeo's 210.11B placed a limit on how much area a dwelling branch circuit could serve.

However, a second look at 210.11(B) shoots this down:

"Branch-circuit overcurrent devices and circuits shall only be required to be installed to serve the connected load. "

In other words, you don't even need enough branch circuits to meet the 3VA per square foot rule.

Steve
 
romeo said:
Would NEC section 210.11(B) apply here? It reads in part The load shall be evenly proportioned among multioutlet brach circuits within the panelboard. Does this mean that it is not permissable to have 20 general lighting outlets on one circuit and ten on another?
Click to expand...
I agree with Larry. There is no predicting where the loads will end up, regardless of receptacle layout.

iwire said:
As much as I hate this method it is generally effective. :evil:

Inspector: I would like you to break up these bedrooms on more circuits.

Contractor: I don't have to.

Inspector: I have to go get my measuring tape and see if all the staples are 4.5 feet or less apart.
Click to expand...
He wouldn't say that in one of my houses. I am a little staple happy. :D

Let's face it, a fella who would put four bedrooms on an AFCI is going to be subject to some scrutiny. Do we pity him for that? No, his slipshod practices bring that on himself.

Should he be failed for it? Under no circumstance.

If we don't like the way things are, we are all invited to submit a proposal to the NFPA correct those items. There's no reason to embrace anarchy to get an extra AFCI circuit in a house. :)
 
romeo said:
Would NEC section 210.11(B) apply here? It reads in part The load shall be evenly proportioned among multioutlet brach circuits within the panelboard. Does this mean that it is not permissable to have 20 general lighting outlets on one circuit and ten on another?

romeo
Click to expand...

I believe 210.11(B) does apply here, but I don't think it is applied by counting the number of receptacles. That section specifically talks about "load calculated on the basis of volt-amperes per square meter or per square foot". I think the load is required to be evenly proportioned by having the circuits supply roughly equal floor areas.

If the circuit serving 4 bedrooms serves a much larger area than other general purpose circuits in the panelboard, then I believe it is a violation of 210.11(B). I am, however, having a hard time understanding what the last sentence of that section is trying to tell us. Any ideas?
 
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