Electric Problem or overloading the circuit

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Hey Guys, I have a double 20 amp breaker that is connected to each other. I have one side running the kitchen and one side running the washing machine in the garage. I was told this is a standard practice, however, I have a portable hot tub that I use in my garage that I only use when not using the washing machine. The hot tub is plugged into a GFCI outlet located about 5 feet down the wall off the washer receptical that was installed before I moved in.
Here is the big problem, I have just noticed a piece of conduit that comes off the furnace that was buzzing, getting hot and it stopped after turning off the hot tub, the other day I was running items from the kitchen and the conduit got so hot it was burning paint off the wall. I shut off the double 20 amp breaker and it cooled down. It now gets hot with that breaker off and running a space heater upstairs that is on another breaker. I have the breaker off on the furnace and am stumped to what is going on or how this my be wired. The conduit going to the furnace goes to a junction box on the wall that has some sort of relay on the top of it. Any help would be great. Thanks
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fzbuilder wrote:

Perhaps you have a broken ground somewhere, and the route to ground via the conduit (or wires inside it) is substituting.
While I can't surmise from what you've told us whether that's truly the case, nor how the system is wired, it sounds dangerous to me. Stuff shouldn't get hot.
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Not only that, but unlrelated circuits should never be ganged.
In anycase, if the breaker is off and the conduit heats up then you haven't shut off the correct circuit. Get an AC voltmeter and check the lines going through the conduit. Better yet, hire somebody and do it before your house burns to the ground.
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AZ Nomad wrote:

I'm thinking that this might be an open neutral type situation, hence the seemingly unrelated stuff getting hot?
In any case, I concur, this is not a problem that has a clear cut troubleshooting flowchart based on what you posted, and is also capable of burning your house down if not fixed ASAP. So get someone to look at it, please.
nate
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Maybe if we had pictures of the setup, the wiring in the panel to the double pole breaker, and any junction boxes in the system, opened and with wires pulled out
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Call an electrician NOW. This is a very dangerous condition, and attempting to diagnose it long-distance through the newsgroups is not likely to be productive. This time of year, you need the furnace -- but that circuit should not be turned back on until the problem has been found and fixed. Call an electrician NOW.
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First, make sure you do not have 20A breakers on 14 guage wire. If you do, change them to 15A breakers now. Thats what could be causing your conduit to get hot. Second, you should only have a double pole breaker for 220V circuits. Although technically it will still work for seperate 110V circuits, it's not proper practice. Also you might have an Edison circuit, that is 2 circuits sharing 1 neutral, so its possible that even though you shut off 1 or 2 breakers to a circuit, the neutral is still being used for your live circuit. So the space heater you were using upstairs could be using the same neutral for the circuits that you shut off. You need find out how your lines were run, particularly in that junction box.
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On Wed, 23 Dec 2009 13:56:58 -0800 (PST), Mikepier

If that is the case in North America something is DEFINITELY waired wrong. With a ganged breaker, the neutral, if shared by two circuits, would be share ONLY by the two circuits on the shared breaker.
And the double pole brakers can (and should) be used with split receptacles, but NEVER with different circuits physically in different parts of the house.

And it it IS, get it rewired properly YESTERDAY if not sooner.
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wrote:

Piffle. That is *not* a requirement of the U.S. NEC -- it might be of the CEC, I don't know, but it's definitely not a requirement here.
There's nothing wrong with running a 3-wire circuit from the panel to a point some distance away, then splitting it out into two individual circuits that go in opposite directions.
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He's not a troll and exactly what is dangerous about this? What Doug has described is an Edison circuit which is a shared neutral circuit using opposite legs on two breakers and is recognized as OK under the NEC. If there is anything in the NEC that says the two sides of the circuit can't go in different directions, I'd like to see it.
In practice, I've never been a big fan of Edison circuits for a variety of reasons, but now that the NEC requires that the two breakers be ganged together, it removes one of my previous main concerns.

That advice I strongly agree with.
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snipped-for-privacy@optonline.net wrote:

Since the NEC is now requiring AFCIs for more stuff, doesn't that pretty much rule out Edison ckts. for new construction? OR are there double AFCI breakers available?
nate
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There are double ground fault breakers. Code calls fo rthem on larger hot tubs.
The hot tub needs a new dedicated circuit on a new breaker. The rest of it needs to be investigated because it sounds a lot like 14g on a 20 amp breaker possibly with a shared neutral. These hot tub companies tell people they have tubs that can be plugged into existing circuits and that's just crap.
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In wrote:

You need to re-read his situatioin unless you're trolling, too.

On ganged breakers? I can't cite it, but no, that's not allowed. One ganged breaker can prevent the other, if overloaded, from breaking in time to prevent problems. It is dangerous.

Catch up your reading and if you have any reading comprehension at all, you'll understand. It appears to me you might also be a troll.
What Doug

For 220Vac, yes. For two 110V ckts, no.
If there is anything in the NEC that says the two sides of

ONLY for 220V ckts. NOT any sort of 110V ckt!
I do believe we have a troll here. Go ahead and flail, it's your liver, not mine.
Twayne

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Of course you can't cite it -- because (a) you don't know anything about electricity, (b) you don't know the Code, and (c) it's not a Code violation.
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In wrote:

Then perhaps you can cite something. Show me an Edison ckt in the NEC. Or even in your local code books; I'm not fussy.
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Stop making a fool of yourself and calling others, who are correct, trolls. The NEC is not readily available online because they charge for it and since on one else here is arguing Edison circuits are code violation, YOU should do the search and you will learn. Just do a google of this newsgroup and you will see many discussions on 120V Edison circuits, which have been allowed under the NEC for a long time. There was one here just a couple weeks ago.
In the last couple years, the code was revised so that the breakers on the two legs must be tied together, Googling in the newsgroup will show agreement to the above, including several licensed electricians. Or you can go google Edison circuit on the web and find plenty of info that shows it is allowed.
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snipped-for-privacy@optonline.net wrote:

Actually, it is. 2008 NEC is at http://nfpaweb3.gvpi.net/rrserver/browser?title=/NFPASTD/7008SB 2005 NEC is at http://nfpaweb3.gvpi.net/rrserver/browser?title=/NFPASTD/7005SB
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Here you go. The 2008 NEC is online at http://nfpaweb3.gvpi.net/rrserver/browser?title=/NFPASTD/7008SB
Multiwire branch circuits (aka Edison circuits) are described in Article 210.4
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In wrote:

EXCELLENT link, Doug! I've often searched for a cohesive presentation of the NEC and never found it; only pieces here & there and those never allow you to check into the outside references, etc.. I definitely appreciate it as I'm sure others do and it definitely gives you a top-credibility rating. It does provide verification, IMO, that one overloaded ckt on one leg and very light load on the other, under fault conditions on the first leg, could cause overheating and other unforeseen problems, especially in a miswired case. In theory equal loads on each leg will result in zero current flow in the neutral, which is as I understood it. It does still appear though, that a fault on one leg and little load on the other could result in substantial current flow, then adding the fault conditions ... .
These following aren't critical questions at the moment so feel free to ignore them if you find them intrusive:
1. One thing is confusing however, that you might be able to explain. In Definitions (100) for Branch Ckt, Multiwire, it states that: "... branch ckt that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the ckt and that is connected to the neutral or grounded conductor of the system"
It _seems_ to say the voltage between the two ungrounded conductors and the neutral will be at the same potential as the ungrounded connectors? I seem to have a brain-freeze again! Can you clarify what that means? The following ref to "neutral or ungrounded conductor of the system" seems to make no sense then and obviously it has to.
2. I've never actually had my hands on a double pole breaker and Google hasn't given me the answer to this one: Are the breakers still independent of each other? I don't think that makes sense so, assuming I'm right, how is it that an overload on one isn't affected (delayed, held from tripping) by the force the other needs to be opened? I thought maybe there was a different internal structure somehow and they were electonically opened somehow, but I can't find proof of that either. I did find one page (crecibility unknown) that said both breakers operated simultaneously, but without internal electronics of some sort I can't see how the drag from one doesn't affect the other?
Thanks again for the very valuable lead,
Twayne
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In that case, you haven't searched very hard; the NEC has been online at least since the 2002 version, and links have been posted in this newsgroup repeatedly. Any of the major chain bookstores (Barnes&Noble, Borders, etc) will have a copy in stock or be able to order one. You can buy it directly from the NFPA. There are copies on eBay. You can buy it from Amazon.
Since you have as good as admitted that you haven't read it, perhaps you can understand why nobody takes you seriously when you proclaim your misconceived notions as fact -- and why I keep telling you to stop giving electrical advice: you don't know what you're talking about.

Now that you know where the Code is, you no longer have any excuse for not knowing what it says.

It does nothing of the kind. Overloading either leg will trip the breaker and disconnect both legs.

You mean, *only* if miswired.

Correct. Unfortunately, that is the *only* thing you got right.

It appears that way only because you don't understand how it works. In a properly wired Edison circuit, the current in the neutral can never exceed the current in *one* hot leg.

Yes....
No, it neither says that, nor "seems to". There is absolutely *nothing* in that paragraph to indicate, imply, or suggest that. In fact, it means exactly the opposite: that they will *not* be at the same potential WRT each other as each is WRT the neutral.

One clause at a time:
"branch circuit that consists of two or more ungrounded conductors" = a branch circuit having two or more hot wires
"with a voltage between them" = each of the hot wires is on a different leg of the service (if they were on the same leg, there would be no voltage between them)
"and a grounded conductor" = and a neutral wire
"that has equal voltage between it and each ungrounded conductor of the circuit" = voltage between the neutral and each hot wire is the same as between the neutral and every other hot wire
"and that is connected to the neutral or grounded conductor of the system" the circuit neutral must be grounded at the panel.

And you accuse trader4 of having reading comprehension problems -- !
It doesn't say that. It says "neutral or GROUNDED conductor" -- which makes perfect sense to anyone who understands residential electrical wiring.

Yet you consider yourself competent to comment on what types of circuits may or may not be used with them, and the relative safety thereof.
Amazing. Simply amazing.

No, of course not. They are mechanically connected with a handle tie; some also are connected internally ("internal common trip"). If they were independent, it wouldn't be a double-pole breaker. It would be two single-pole breakers.

It trips with ample force to bring the other one along with it, even if the only connection is an external tie.
Move a breaker handle from the 'off' position to the 'on' position; notice how much force you have to apply to it. Now nudge it from 'on' to 'tripped' -- see how easy that was, and how forcefully it snaps over? More than enough to trip a second handle tied to it.

I guess that depends on what kind of time lag you would consider "simultaneous". In the case of an internal common trip, they would in fact trip simultaneously. With an external handle tie, there must be some tiny lag due to mechanical play in the connection, but it's very small.

The effect is minuscule.

Like I said -- now that you know where the Code is, you no longer have any excuse for being ignorant of it, or dispensing clueless advice that contradicts it.
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