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12-13-2007, 07:40 PM   #1
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## One circuit, two breakers?

I was trying to help a friend figure out an electrical dilemma. She has a circuit with lights and a few outlets on it, that is not de-energized by any one breaker in the panel, you must throw 2 breakers to de-energize the circuit. I imagine that, somewhere over time, someone crossed these circuits in an outlet or switch somewhere, but all of the outlets read 110v. Why might this be?

12-13-2007, 07:50 PM   #2
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The panel has two legs of 120 volts in it. When you have a double pole breaker it draws power from both legs which get you 240 volts. The circuit is feed from two breakers that are on the same leg. Since they are on the same leg it will only be 120 vlots. You will need to start taking the outlets and switches apart and try to find where the circuit is feed from, both feeds.

 12-13-2007, 08:00 PM #3 Member   Join Date: Mar 2005 Posts: 152 Rewards Points: 150 I guees I don't completely understand the reply. I've installed double-pole breakers to bring 240v to a dryer before, and the breaker simply snaps into two places on one leg inside the panel, not both legs at one time, and each hot wire on the double pole breaker brings 120v to the outlet to equal 240v. This issue is with two separate, single pole breakers in two separate spots on the same leg inside the panel, that must both be switched off to de-energize the circuit. My experience has been that each circuit is controlled by one breaker (single or double) but that's not the case here.

 12-13-2007, 08:21 PM #4 Licensed Pro   Join Date: Mar 2007 Location: SC Posts: 1,571 Rewards Points: 1,000 This 120V circuit is INCORRECTLY wired if it is controlled by two breakers. What Ponch was saying is you will have to trace each wire as it leaves the panel to determine where the crossover was made.
 12-13-2007, 08:25 PM #5 Member   Join Date: Dec 2007 Location: Baltimore, MD Posts: 1,802 Rewards Points: 1,000 Sound like someone miswired a junction box and fed the circuit from two power sources. Or, it was a multiwre circuit that was wired wrong when a receptacle was replaced. You may have to check each receptacle and light switch to make sure there is only one line wire coming in.
 12-13-2007, 08:42 PM #6 Union Electrician     Join Date: Nov 2007 Location: Chicago, USA Posts: 615 Rewards Points: 500 The two breakers are on the same phase and thus only deliver 120 volts. In theory, you could hook up 100 breakers on the same phase to the same outlet and it will only be 120 volts. Find out if she had any work done recently and start there. If was a recent "rehab" it'll take a bit of detective work. There will probably be some 'area of overlap' in the circuiting. That is to say, it picked up the extra feed from a nearby room or perhaps something above or below it. Good Luck!
12-13-2007, 09:44 PM   #7

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Quote:
 I've installed double-pole breakers to bring 240v to a dryer before, and the breaker simply snaps into two places on one leg inside the panel, not both legs at one time, and each hot wire on the double pole breaker brings 120v to the outlet to equal 240v.
Not true a double pole breaker connects to both legs not one leg otherwise you would not have 240 volts between legs. If it connected to the same leg each wire would have the same voltage wave and would only get 120 volts to the dryer. You must have both legs to equal 240 volts. When you move vertically down a column on a modern panel every other space is the opposite leg. So a double pole breaker connects to both legs.

Quote:
 This issue is with two separate, single pole breakers in two separate spots on the same leg inside the panel, that must both be switched off to de-energize the circuit. My experience has been that each circuit is controlled by one breaker (single or double) but that's not the case here.
Have you had the cover off the panel and looked at the wiring connected to these breakers?

 12-14-2007, 12:22 PM #8 Newbie   Join Date: Dec 2007 Posts: 12 Rewards Points: 10 Good news - turns out that this was due to both circuits wired to a double switch. Problem solved by wiring each to a single and separate switch. Yippee!
 12-14-2007, 12:48 PM #9 Member   Join Date: Mar 2005 Posts: 152 Rewards Points: 150 Thanks to stubbie for the info on double-pole breakers, I did not know that, now I do. I also see that my friend Yippee seems has solved her problem last night, so that's good. Thanks for all the replies.
 12-14-2007, 05:56 PM #10 Electrician philosopher   Join Date: Aug 2007 Location: Lilburn, GA Posts: 838 Rewards Points: 500 Bill, how did you know Yippee was a girl? Do you have special powers? Andy
12-14-2007, 06:02 PM   #11

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 Originally Posted by Andy in ATL Bill, how did you know Yippee was a girl? Do you have special powers? Andy
See post #1.

 12-14-2007, 06:05 PM #12 Electrician philosopher   Join Date: Aug 2007 Location: Lilburn, GA Posts: 838 Rewards Points: 500 I'm frequently easily confused. HH, I bet Honk misses ya. Why don't you go on over to the hot tub thread and say hey?
12-14-2007, 06:30 PM   #13

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 Originally Posted by Andy in ATL I'm frequently easily confused. HH, I bet Honk misses ya. Why don't you go on over to the hot tub thread and say hey?
I lost track of that thread at about post 100. No need to get in the way of romance.

 12-14-2007, 06:33 PM #14 Electrician philosopher   Join Date: Aug 2007 Location: Lilburn, GA Posts: 838 Rewards Points: 500 Aww shucks, HH. It's like a soap...Just jump in about five posts back and you'll be all caught up.
08-09-2012, 04:36 AM   #15
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This is an older post but it is exactly the same problem that I'm having with my "OPEN CIRCUIT". Thanks to all who replied to Yippee because its given me a fresh outlook and maybe I can go at this from a different angle and fix mine as well. I knew I hadn't seen this type of configuration before and I agree with HH, this is not the norm nor is it the correct way to wire outlets. My outlets are not switch controlled so I either have a junction box with loose connections or an outlet that the wire has worked loose from back that feeds the now dead receptacles.

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