AFCI Circuit capacity

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Glen Willard

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Is there a limit of bedrooms you are allowed to put on 1 AFCI circuit? I wire alot of apartments all over the state of Florida and I have always put no more than two bedrooms on one AFCI circuit.
 
If you had a million bedroom house, you could put all one million bedrooms on that AFCI permissably. Bad design, but compliant.
 
mdshunk said:
If you had a million bedroom house, you could put all one million bedrooms on that AFCI permissably. Bad design, but compliant.
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Okay, I've seen this said a zillion times, and every time I want to ask how this jibes with 210.11 (B) --

Load Evenly Proportioned Among Branch Circuits
Where the load is calculated on the basis of voltamperes per square meter or per square foot, the wiring system up to and including the branch-circuit panelboard(s) shall be provided to serve not less than the calculated load. This load shall be evenly proportioned among multioutlet branch circuits within the panelboard(s). Branch-circuit overcurrent devices and circuits shall only be required to be installed to serve the connected load.
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'Splain?
 
tallgirl said:
Okay, I've seen this said a zillion times, and every time I want to ask how this jibes with 210.11 (B) --

'Splain?
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A million bedroom house will have 3 or 4 hundred air conditioners, a few hundred kitchens, many living rooms, etc. The load will be even.

Trying to proportion the load in a dwelling is a fool's errand anyhow.
 
mdshunk said:
A million bedroom house will have 3 or 4 hundred air conditioners, a few hundred kitchens, many living rooms, etc. The load will be even.

Trying to proportion the load in a dwelling is a fool's errand anyhow.
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Alright, so I went searching on the history of 210.11 (B) debates and found this.

It's my understanding that the "everything else" circuits from that post have to be proportioned.

I understand that I can put 500 receptacles in a single bedroom, and all 500 can be on 1 20A circuit. But I don't see how if there are 4,000 "everything else" circuits that are required for the million bedroom house, 3,999 can be used for one of the 465 living rooms and the other 464 same-sized living rooms and all 1 million bedrooms can be stuck on that one remaining "everything else" circuit.
 
I generally over exaggerate to make a point. Sorry about that. I remember once talking about a zillion amp service needing only #6 to ground rods. My head hurt now. Time for bed.
 
mdshunk said:
If you had a million bedroom house, you could put all one million bedrooms on that AFCI permissably. Bad design, but compliant.
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I don't think that possible, with out a special Breaker, due to the fact you would have to derate the wire because of length. To get a million bedrooms in a house you would need two things, a minimum size per bedroom to make it a ligitimate bedroom, normally no smaller then 100 sq ft,10' x 10'. That would be a minimum of 10 million sq ft of bedroom. Given that #14 is good to about 55' and #12 about 65' <15amp and 20amp> If your sub panel was in the middle and all the bedrooms your shortest distance to the outside wall of the bedrooms would be over 10 miles. That is a very rough number. I dont know what size wire that would take at 120 volt. What ever the size I don't think it would fit on a spec grade 15-20amp receptical.
 
acrwc10 said:
I don't think that possible, with out a special Breaker, due to the fact you would have to derate the wire because of length. To get a million bedrooms in a house you would need two things, a minimum size per bedroom to make it a ligitimate bedroom, normally no smaller then 100 sq ft,10' x 10'. That would be a minimum of 10 million sq ft of bedroom. Given that #14 is good to about 55' and #12 about 65' <15amp and 20amp> If your sub panel was in the middle and all the bedrooms your shortest distance to the outside wall of the bedrooms would be over 10 miles. That is a very rough number. I dont know what size wire that would take at 120 volt. What ever the size I don't think it would fit on a spec grade 15-20amp receptical.
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All kidding aside, let's limit it to something more realistic. Ten bedrooms, 1 kitchen, 10,000 sqft. At 3VA per sqft, that's 30kVA, or 15 20A circuits for lights and outlets and whatnot. Subtract the bathroom and SABC and ... circuits and whatever's leftover is lights and receptacles.

For the sake of this discussion, let's say each bedroom is 400 sqft -- 20' by 20'. That's 4,000 sqft or 40% of the total square footage. Can someone explain how that 40% of the square footage doesn't require at least 2 (14%) of the 15 20A circuits?
 
To be honest

To be honest

I do not understand where you guys are going with the million bedroom house. Sounds like a pain to maintain if you ask me.. but Tallgirl I am interested in your last question, but do not think I understand. First off; 3VA per square foot is a course calc I believe, we should not really use it for absolutes. Second, let's say you were "really" designing a home 10 bedroom 1 kitchen. (Which really would be two kitchens, but whatever).. If I were doing it, I would send 1 20amp to each bedroom, especially if it was 20' x 20'. Yes,, I know it is overkill, but a home that big,, big budget etc. the cost to do it from the beginning is small. I say this because, it is not a bad thing oversize a circuit as long as you don't super-oversize it. So even thought I do not think I understand your question, my answer would be that I would send 10 circuits to the bedrooms not 2.
 
Why has this gone off on such a tangent ?? leave SABC`S,gfci etc out of the pic.My rule of thumb 1 circuit for every 600 sq feet of living space.But that does change when huge ent. ctrs. are added they get a dedicated circuit.

The OP was are there a limit to the # of bedrooms allowed on an afci circuit? That depends on the sq footage of the rooms.If someone can`t figure out the # of bed rooms allowed on ONE circuit with sq. footage then they need to stand in a lightning storm holding up a ground rod.:)

Now if the question was are there a # of receptacle outlets allowed on an afci circuit the answer is a definitive NO.

Done ranting, ducking for cover here comes the stoning :)
 
"The OP was are there a limit to the # of bedrooms allowed on an afci circuit? That depends on the sq footage of the rooms.If someone can`t figure out the # of bed rooms allowed on ONE circuit with sq. footage then they need to stand in a lightning storm holding up a ground rod.:smile:"

Now if the question was are there a # of receptacle outlets allowed on an afci circuit the answer is a definitive NO.
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can I get an Amen:rolleyes:
 
allenwayne said:
Why has this gone off on such a tangent ?? leave SABC`S,gfci etc out of the pic.My rule of thumb 1 circuit for every 600 sq feet of living space.But that does change when huge ent. ctrs. are added they get a dedicated circuit.

The OP was are there a limit to the # of bedrooms allowed on an afci circuit? That depends on the sq footage of the rooms.If someone can`t figure out the # of bed rooms allowed on ONE circuit with sq. footage then they need to stand in a lightning storm holding up a ground rod.:)

Now if the question was are there a # of receptacle outlets allowed on an afci circuit the answer is a definitive NO.

Done ranting, ducking for cover here comes the stoning :)
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Thanks, Allen, you answered my question. I think there was a point of confusion between "how many receptacles?" (the answer is "However many you want -- the more the merrier", in the eyes of the JW I work with most these days :) ) and "how many bedrooms?" (and I think that's based on square footage, etc., as I read from your post).

And me and my cat are back in Happy Katrina Land. I'll be sure to post however many examples of Really Bad Wiring I can find :D
 
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