15 &20 amp breakers

[LarryFine]

Take THAT you 15-amperes.

Wouldn't that be "amperers?" :wink:

 

[claytazdaisy]

I have to point out that devices do not use electricity.

thats what i was sayin

 

[claytazdaisy]

That's the one thing you've said that I agree with. :smile:

But, the NEC does back up what the other guys are telling you.

i never disgreed with the other guys. somebody asked about how many $ and box.es or something weird and i said it didnt matter. its the lights that have to be accounted for. just didnt understand the way it was said. just had no relevance to the original question

 

[jeffhornsby]

I had someone ask me same question. I guess some non-electricians only allow a certain number of boxes per curcuit, and a certain number of lights per switch which makes no sense.

 

[jeffhornsby]

Also the 125% rule has to do with the breaker.
Breakers are designed to carry 80% of there rating for at least three hours. If a breaker carries current close to its rating for to long the breakers overload will get to hot and trip.

That's why the 125% rule does not apply to the conductor's ampacity, and the branch circuits grounded conductor if the breaker and assembly is rated to operate at 100% 210.19.(A)1 exception 1 & 2

Also the 125% rule does not apply to the overcurrent device if the breaker and assembly is rated to operate at 100% 210.20 (A) exception

 

[iMuse97]

I had someone ask me same question. I guess some non-electricians only allow a certain number of boxes per curcuit, and a certain number of lights per switch which makes no sense.

Many electricians I've met essentially do this in resi. work, it's their rule of thumb: they count openings, and when they get to about 10 (I've talked to some who stretch it to 12), they start a new circuit.

I'm really liking this thread, b/c we have very smart people discussing a subject which has been gone over hundreds of times, and still people wonder about it.

My own rule in resi. typically loaded a lighting circuit to an estimated 80% if all lights were on, but even so, resi. lights are not be considered a continuous load.

With resi. general use receptacles, I ran plenty of 15 amp circuits in very high-end homes. I would consider running 20 amp receptacle circuits in my own house, but I've never tripped a circuit, except when I ran the skill saw and work lights from the same receptacle on the back deck. That circuit also supplied the backyard spots (400w total), and dining and kitchen lights which were all on.