In my basement, I need to run conduit for two kitchen circuits. It is a straight run of about 13 feet. Is there a reason (code/safety) that I cannot run both circuits through one piece of conduit?
Thanks
Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read.
-Groucho Marx
-Groucho Marx
Replies
Is there a reason (code/safety) that I cannot run both circuits through one piece of conduit?
No.
What size conduit, what size wire?
4 strands of 12 guage wire, through (sorry I don't have the size handy) 3/8 I think.
Anyway, it is the smallest size conduit, I believe.
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
It's OK. You can even share a neutral, assuming that each circuit comes off a different leg. If you don't understand this, then you better pull two neutrals
I'll probably do the two neutrals, just because it's something I understand better.
But for the record: When you say a different leg, do you mean off opposite hot leads in the panel? Or simply off any different breaker?
Thanks for the help.Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
Not to bust your chops but they're called phases (at least thats what my cousin calls them). Not legs. I guess both would work.
"Not to bust your chops but they're called phases (at least thats what my cousin calls them). Not legs. I guess both would work."Legs is better whay of noting it.Otherwise you can get into a LOOOOOONNNNNG discussion about whether it is a two phase or single phase circuit.(Almost) Everyone understands legs, but when you get into phases it can become confusing.FWIW if you run 2 seperate circuits, 4 equivalent current carrying conducotrs, you have to derate the wires to 80%.However, contrary to "popular opinion", #12 wire is rated for 25 amps. So, unless there are other derated requirements, 2 #12 circuits can be run in conduit and still be rated for 20 amps.But if you need to run more, using multiware circuits (shared neutrals), you can run up to 6 120 volt circuits in the conduit..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
"Otherwise you can get into a LOOOOOONNNNNG discussion about whether it is a two phase or single phase circuit."
Been there, done that. Several weeks ago I posted such a question, something about a 220 volt motor. It took me two weeks and numerous re-readings to sort out the discussion (you posted in it) that followed. Quite a lesson in electrical engineering, at least for a layperson like me.
(By the way, after following that thread and doing some Googling of my own on the topic, I agree with the "it's not two phases" camp.)
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.-Groucho Marx
Edited 11/16/2007 11:20 pm ET by musashi
"FWIW if you run 2 seperate circuits, 4 equivalent current carrying conducotrs, you have to derate the wires to 80%."
When you say 'current carrying conductor' do you refer only to the hot, or to both the hot and neutral?
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
It is EQUIVALENT current carrying conductor.
It is based on the heatinf of the wiring in the conduit.Thus for a 2 wire circuit the count is 2. Hot and Neutral as both carry the full amount of circuit in that circuit.For a multiwire circuit (2 hots and a neutral on a single phase circuit) the count is also 2. There are 2 worse case conditions. The first is with full current on one of the hots and the neutral. The other case is full current on each of the hots. Then the neutral carries zero current. Then when you get through the conduit you can split the multiwire circuit into 2 120 volt circuits..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I have one follow-up question to the aforementioned long discussion:
According to the people who posted - as far as I understand - the two hots in a 220 circuit are split phase/180 degrees out of phase/next cycle of same phase/call it what you will.
Why then, does a 220 double pole breaker take power off of just one leg inside the panel? Doesn't that go against everything that was said?
Just curious.Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
"Why then, does a 220 double pole breaker take power off of just one leg inside the panel? Doesn't that go against everything that was said"No, a true 2 pole breaker will make contact with both legs.Most modern breakers panels used in residential applications (Sq D (QO & HomeLine), CH (CH & BR series), Murry, etc) the contacts on the hot bus bars alternate. And a 2 pole breaker takes 2 slots and contacts both buses.A tandem breaker is 2 single pole breakers in the space of a single pole, but it only makes one connection. So it can only be used for 2 120v circuits.However there is a quad breaker that is 2 tandems mounted side by side so that each tandem is on a different leg. Then a tie bar is used between the inner 2 breakers to form a 2 pole breaker and 2 single pole breakers.The one exception to this is GE panels. At least some of them take a 2 pole breaker that fits in a single space. I don't know how the buses are arranged in those..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
"Most modern breakers panels used in residential applications (Sq D (QO & HomeLine), CH (CH & BR series), Murry, etc) the contacts on the hot bus bars alternate. And a 2 pole breaker takes 2 slots and contacts both buses."
Got it. They alternate! Now...finally...that whole discussion is making sense to me.
Thanks
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
Musashi,
Is this job over your head? You don't know how panels work, and you have no idea about EMT sizes. I'd reconsider if I was you
Yeah, most jobs I do are over my head. (I'm a homeowner, by the way, not a contractor.) But it's done.
I am always aware of potential problems, so I ask lots of questions on the way, both locally, among contractor friends, and in Breaktime.
I've been doing major work on this house for three years (we're living in it, and I have another job, so it takes time), and although there have been a couple of minor setbacks, I haven't done any major stupids yet.
Thanks,
Musashi
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
I called them legs forever, until my cousin (btw he's an electrician) started correcting me.
I'd like to learn more about derating for running wire in conduit. Any suggested reading?
It's a burn when you correct someone, and you're the one who's wrong, huh? Both terms are colloquially correct at times. The truly correct term would be (I believe) pole. Electricians get in the habit of calling the separate legs "phases", just like they get in the habit of calling 220v (or 230v) 240v.
But the fact is most houses are wired with a 120/240v split phase system. Which by definition is (duh) splitting a single phase
Read about it here:
http://en.wikipedia.org/wiki/Split_phase
Edited 11/18/2007 9:54 am ET by McMark
I guess thats what I get for listening to my cousin.
You should be fine. I believe its 1/2" conduit.
Thanks to all for the advice.Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
-Groucho Marx
have at it..
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