Electrical Wiring Question

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Where does a dual 20 amp breaker put both breakers on the same phase? Which panel (manufacturer) does this?
Obviously confirming both breakers are on separate phases is desirable. But what dual breaker in what panel puts the same phase on opposite legs? If this occurs, then there is no reason for a dual breaker. There is no reason to have a dual breaker where both legs are on the same phase. Which manufacturer makes such a useless product?
Chris Lewis wrote:

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w_tom wrote:

Most of them do. Even Square D makes "QOT" 15A and 20A breakers for their QO line. They let you overstuff a full panel.
Best regards, Bob
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I believe you are confusing 'two breakers in one slot' with something completely different. Defined were two 20 amp breakers tied together - physically - so that if either breaker trips, then both trip. These latter type breakers are required for 240 volt service. I repeat my question. Where do such breakers exist where both 20 amp circuits are on the same phase?
This is not same as two completely separate 20 amp breakers in one body - in one slot - which would be irrelevant to this thread. Two breakers in one slot are not intended for 'common neutral' operation and do not have both breakers tied together - to trip both if either trips.
zxcvbob wrote:

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I installed a (then) brand new Federal Pacific (US: Federal Pioneer) panel about 12 years ago. The backplane slots were arranged as (leg A and leg B) AABBAABB... You had to be careful to insert the two-pole breaker in the right slot.
Whether they still do that I dunno.
Yeah, real dumb. But there you are.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
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Thanks for the 'heads up' on one example to watch for. Anyone have any other examples of dual breakers that can be installed this way - so that both sides of the 'common trip' breaker will be on same phase?
Chris Lewis wrote:

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On Wed, 27 Apr 2005 21:49:26 -0400, "Alexander Galkin"

I think it's only required if a single device is feed by both 'hots' (example a split receptacle with the top on one phase and the bottom on another). But I have to check the NEC to verify this. Even if it's not required, local codes can require this so check with your authority having jurisidction.
tom

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You're correct. Can you run 40 amps through his orange apron and see if it lights up?
--

Christopher A. Young
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No, he's not correct. Haven't you bothered to read *any* of the other posts in this thread?
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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Doug Miller wrote:

Doug Chill out. The Home Depot chap was correct in that it is a perfectly acceptable practice to run multi wire branch circuits. Every north American service or feeder is an Edison circuit. They are used for almost every "home run" in commercial work.
You do have to know what you are doing to work with multi wire branch circuits safely. If you don't know what you are doing then you should not even take the cover off of an electrical box, let alone remove the door assembly off of a panel cabinet. I have to say that the idea that electrical construction techniques should be dumbed down to avoid injury to ignorant harry home owner types irritates me. Anyone that does not know how to test circuits for voltage before working on them should not be doing electrical work.
Unlike some other posters on here I am not opposed to sweat equity electrical work as long as the person doing it has taken the time to learn enough theory and technique to do the work safely. Anyone who is not willing to invest the requisite time to learn to work safely, and yet still insist on working with electricity, should be wearing one of Jeff Foxworthy's signs so that the rest of us can stay clear of the after affects of their utter stupidity. -- Tom H
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[snip remainder] You've missed the point rather badly, I'm afraid. Yes, the Home Depot guy was right -- as has been discussed at some length for two days now, including specifically why it's OK, and what the "gotchas" are. Then Stormy comes along and says that the OP was right ... remember what the OP said? The OP thought that it was *not* OK because he feared the neutral would carry double the load. But the OP wasn't right, and, as I've said, that's been discussed at some considerable length here, and Stormy obviously didn't heed any of it.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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Doug Miller wrote:

My apologies. I read your post in the wrong context. -- Tom H
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current setup
Bathroom distribution:
2 breakers : 1-15A GFI, 1-15A, 1 pole duplex . 2 wires from breakers, 1-2wire, 1-3wire
2 wire cable - connected to A of 15A duplex breaker - running to GFI receptacle
3 wire cable - 1 hot connected to B of 15A duplex breaker - runnig to lights, fan - 1 hot connected to GFI breaker - running to floor heating cables
- neutral connected to GFI breaker
is this setup OK? Does the GFI breaker neutal works ok if shared between 2 breakers? Originally this setup was planned beacuse the receptacle is on the other side of bathroom. 3 wire cable runs to wall with switches for lights, afan, and floor heating thermostat. Will the circuit work, or is there a chance of GFI breaker tripping? If needed, I can rerun the cables, but beforte I get into it, I want to be sure that it is required.
Thanks.
martin
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No, it won't work; so if it does, it must not be wired that way. The 3wire neutral must go only to the floor heating cable; the lights must use some other neutral. It is not necessarily unsafe, but odds are it is. At an absolute minumum you must have net 0a going through every metal hole, such as the one in the breaker box. Also, the two hots that share a neutral must go to opposite legs. If you can do those, it may be safe, but it will still be ugly. It will still be potentially dangerous because the next guy will have no idea what you have done.
It should be wired so that the 2wire goes between the GFCI breaker and the floor heating cable and the 240v breaker runs the light and outlet via the 3wire. And of course each neutral must go to the proper hot.

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Wrong as usual, toller.
You did manage to get part of it right this time: the GFCI won't work with a shared neutral. But there's no reason at all why he can't share a neutral between the floor heating cable, and the lights.

Right here is another example of why you have NO BUSINESS giving anybody electrical advice, and why I keep busting your chops for it: YOU'RE DANGEROUS.
He doesn't *have* a 240V breaker, idiot. He has a single-pole duplex breaker. (Didn't you read?) If he wires the 3-wire cable as you suggest, to the breaker he has, he's *guaranteed* to overload the neutral, and likely start a fire.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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Martin, the bathroom receptacle(s) is required to have one dedicated 20 amp circuit (#12 wire) feeding it as per the current National Electrical Code. It won't pass inspection with a 15 amp feed.
You cannot use a three wire to feed two separate circuits and have one protected by a GFCI circuit breaker. Because of the design of the GFCI and how it operates it will trip each time there is current on both legs concurrently. It just doesn't work with a shared neutral. You need to use a two wire cable for the GFCI breaker protected circuit. You might get it to work by using a GFCI device at the load end connecting one hot and the neutral of the three conductor cable, but I suggest that you change to a two wire to keep nuisance tripping to a minimum.
You should check the manufacturer's requirements for the floor heating and save the instructions for the electrical inspector for verification.
John Grabowski http://www.mrelectrician.tv

2
heating
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John, I think he may be in Canada, though he didn't specify

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Thanks RB. I didn't know. My answer above only applies in the USA.

between
other
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The 20A required for bathroom comment applies to the USA only.
The comments about the GFCI not working applies in both places ;-)
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
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Nope. Won't work. John Grabowski got it right in his post; toller (as usual) got it wrong, and you're risking a fire if you follow his advice.

Nope. Doesn't work at all.

Nope, won't work - GFCI is guaranteed to trip almost every time.
Now, you *could* get a 240V (two-pole) GFCI breaker, and use that for your 3-wire cable, but: a) they're waaaay expensive; much cheaper to run new cable, and b) you probably need to run new cable anyway, because you need 12ga copper for the 20A circuit that is required by Code.

Got the order of those two steps reversed, it seems to me. :-)
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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On Sat, 5 Jan 2008 12:25:05 -0800 (PST), snipped-for-privacy@gmail.com wrote:

Take it loose at the GFI
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