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
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.
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.
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
replace "roosters" with "cox" to reply.
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
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.
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.
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.
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
There are double ground fault breakers. Code calls fo rthem on larger
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.
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.
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,
Often you'll find excellent advice on a newsgroup.
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.
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
"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
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
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