Breaker Sizes

[Frank DuVal]

Someone in authority claims that each outlet or receptacle will use 1.5 amps on average. 80 percent of a 15 amp circuit is 12 amps. 12 amps divided by 1.5 amps equals 8 outlets/ receptacles. That's the golden rule.

Only applicable to commercial circuits. Residential has no Golden Rule!

 

[Frank DuVal]

The Golden Rule in residential is making the customer happy (within NEC rules of course) and collect the Gold!

(Lost time to edit my post by reading the others....)+

I have installed QO and QOB 110 breakers for industrial applications. So they are made and they fit regular QO panelboards.

 

[garbo]

Load demand and designed withhold can be 2 different things. Newer code is recognizing a 10A load and breaker but still requires no smaller than 14G wiring.

As far as the #14 guage this could be think its termed CCA . Copper clad aluminum wire where the outer layer is copper. Only two things things that I see is a cost saving and read the #12 CCA will have a 15 amp rating it has less resistance then #14 copper wire. I would never use the CCA wire.

 

[Rick 0920]

The NEC does not state a maximum number of outlets per circuit. Local jurisdictions may require something different. The NEC does state that the minimum unit load shall not be less than 3 va / sq. ft. (220.14 (J) So if you were to have 1800 sq. ft. of calculated floor area (220.11), if you were using 15 amp circuits, the calculation would be:
1800 sq. ft. x 3 va (watts) divided by 15a x 120v
5400 divided by 1800 = (3) 15a circuits for general lighting
if using 20a circuits:
1800 sq. ft. x 3va (watts) divided by 20a x 120v
5400 divided by 2400 = 2.25 (or 3 since there is no such thing as .25 of a circuit) 20a circuits for general lighting
Where some people are confused by thinking you can only use 80% of the branch circuit, they are either thinking of continuous loads, which dwelling unit receptacles and lights are not, or they are thinking of 210.23 (A)(1) which states that the rating of any ONE cord and plug connected utilization equipment not fastened in place shall not exceed 80% of the branch circuit rating (breaker size).

 

[Fred B]

As far as the #14 guage this could be think its termed CCA . Copper clad aluminum wire where the outer layer is copper. Only two things things that I see is a cost saving and read the #12 CCA will have a 15 amp rating it has less resistance then #14 copper wire. I would never use the CCA wire.

You forced me to look it up. The 14GA "IS" for the CCA. Was going on "what I heard" as not on 23 code. They are allowing copper to as little as #18 in 240.4(D)(1)

This got me looking at 240.5(B)(2)
(2) Fixture Wire.
Fixture wire shall be permitted to be tapped to the branch-circuit conductor of a branch circuit in accordance with the following:
(1)15- or 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of run length
(2)15- or 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of run length

Run length? Is that the length of the fixture wire?

 

[LarryFine]

Run length? Is that the length of the fixture wire?

Yes, not the circuit itself.

 

[garbo]

The NEC does not state a maximum number of outlets per circuit. Local jurisdictions may require something different. The NEC does state that the minimum unit load shall not be less than 3 va / sq. ft. (220.14 (J) So if you were to have 1800 sq. ft. of calculated floor area (220.11), if you were using 15 amp circuits, the calculation would be:
1800 sq. ft. x 3 va (watts) divided by 15a x 120v
5400 divided by 1800 = (3) 15a circuits for general lighting
if using 20a circuits:
1800 sq. ft. x 3va (watts) divided by 20a x 120v
5400 divided by 2400 = 2.25 (or 3 since there is no such thing as .25 of a circuit) 20a circuits for general lighting
Where some people are confused by thinking you can only use 80% of the branch circuit, they are either thinking of continuous loads, which dwelling unit receptacles and lights are not, or they are thinking of 210.23 (A)(1) which states that the rating of any ONE cord and plug connected utilization equipment not fastened in place shall not exceed 80% of the branch circuit rating (breaker size).

Back 50 some years ago we were taught for residential circuits feeding bedrooms, living, dining & family rooms ( but not kitchens ) to use 180 VA load for each duplex receptacle or a maximum of 10 receptacles on #14 copper NM cable feed by a 15 amp circuit breaker & 13 duplex receptacles on #12 copper NM cable and a 20 amp breaker. Usually didn't like to put more then 8 receptacles on a 15 amp breaker or 11 receptacles on a 20 amp breaker.

 

[Rick 0920]

220.14 (L) is for other outlets not covered in (A) through (K). Those would be calculated at 180va per outlet. If you had a 20A circuit,
20A x 120v = 2,400 va (watts) 2,400 divided by 180va = 13.33 Maximum of 13 receptacles
15A x 120v = 1,800va (watts) 1,800 divided by 180va = 10 Maximum of 10 receptacles
220.14 (J) covers requirements for dwellings. Nothing about maximum number of outlets is written there.

 

[JakupstateNY]

I think what he's saying is that you need one circuit for up to 600 square feet of floor area. If you have more than 600 square feet you'll need more than one circuit.

Running separate just ceiling lighting knowing the installs average 10 watt LED bulbs, where I am 1 15 amp breaker circuit covers more sqft than I actually desire to divide up for owner understanding locations and outages etc. 115 10 watt LEDS/PER silly, doable.

 

[roger]

Jake, please update your profile to show what are you semi retired from.