Two breakers to control one outlet?

[jeff48356]

Suppose you get a service call to troubleshoot something, and discover that certain lights and outlets require two different breakers to turn power off to them. How would you approach that? I know that the problem is that at some point, some homeowner or handyman was messing around and wired two hot wires together from different circuits that happen to be on the same leg.

 

[Dennis Alwon]

Often times it is just a loop circuit. Disconnect one breaker and see if everything stays on. I have seen this often. I believe in England they run their circuits in a loop.

 

[ptonsparky]

Suppose you get a service call to troubleshoot something, and discover that certain lights and outlets require two different breakers to turn power off to them. How would you approach that? I know that the problem is that at some point, some homeowner or handyman was messing around and wired two hot wires together from different circuits that happen to be on the same leg.

Let the customer know of the problem. Easiest fix is to put both hots on the same breaker. Some will say you now have paralleled conductors and that is an inexcusable violation. Could be, but some what less of a problem than what you have now.

Next would be to search for the interconnection. You may find it in the first box, or the last. (Always the last)

Anywhere from not bad to horribly expensive to find.

 

[growler]

I believe in England they run their circuits in a loop.

Yes but they also drive on the wrong side of the road, drink tea, have a queen and talk funny.:lol::lol: And don't even try to understand how they count money, British bolt sizes or weights.

 

[norcal]

Often times it is just a loop circuit. Disconnect one breaker and see if everything stays on. I have seen this often. I believe in England they run their circuits in a loop.

32 ampere ring circuit, which is the reason for their fused attachment plugs, a system as archaic as our former (sort of since still allowed in existing installations) practice as using the neutral to ground the frames of dryers & cooking equipment.

 

[infinity]

it's certainly a safety hazard because you could end up overloading the conductors. You will need to find where the two circuits are connected and fix it. Or just disconnect the conductor one of the CB's.

 

[Tony S]

We drive on the right side of the road, colonists are just contrary.

Ring circuits are supplied from a single breaker and therefore a single circuit.

The BS1363 plug and socket is acknowledged worldwide as the safest system.

Your repost?

 

[retirede]

Easiest fix is to put both hots on the same breaker.

Maybe just remove the wire from one breaker and cap it. Avoids the parallel issue.

 

[ptonsparky]

Maybe just remove the wire from one breaker and cap it. Avoids the parallel issue.

You and Infinity have it. Too easy.

Now what the heck am I going to do about the neutral(s)?

 

[hbiss]

Disconnect it too, no?

-Hal

 

[Little Bill]

You and Infinity have it. Too easy.

Now what the heck am I going to do about the neutral(s)?

You can trace the neutrals (providing it is a cable such as NM) by following the black leads on the breaker. Remove one of the neutrals, after shutting off both breakers, turn the breakers back on and see what is not working. Then you could do the same for the other neutral. Most likely, the circuit with the most nonworking items after removing the neutral is the original circuit.

You could then start opening up boxes, which most likely will be a switch box. If you happen to find that the neutrals are also tied together then there is more digging to do.
If you or the HO doesn't want to spend a lot of time on this, then you could check the amp draw on each neutral. If it is within reason, I would just cap off one circuit and call it a day. You might want to tag the disconnected circuit so someone doesn't reconnect it later.

 

[al hildenbrand]

Suppose you get a service call to troubleshoot something, and discover that certain lights and outlets require two different breakers to turn power off to them. How would you approach that? I know that the problem is that at some point, some homeowner or handyman was messing around and wired two hot wires together from different circuits that happen to be on the same leg.

I've had this call a couple times over my career. Other than total wild card weirdness from a DIYer, the most common recurring cause has centered around MultiWire Branch Circuits (MWBCs).

I got a call for help from a newly widowed woman who pretty much lived in her modestly updated 1915 kitchen. The desktop PC was on the breakfast table and all the surfaces and chairs (except one) were stacked with mail, newspaper and magazines. The PC, counter micro, refir, toaster and coffee maker would occasionally overload the circuit. The "circuit" turned out to be a duplex receptacle on each wall of the Kitchen. The panel was in the basement, directly below the kitchen, was 100 A circuit breaker, installed prior to 1975. All the kitchen receptacles were in flexible metal conduit, fished up into the walls of the kitchen.

Her husband had always handled the mechanical chores, during their life together. So, when the kitchen small appliance branch circuit overloaded after his death, she had to face the circuit breaker panel for the first time. Finding two circuit breaker handles in the tripped position, she naturally turned each on. Turning the last one on resulted in a flash of light, both breakers tripping and her calling me.

Turned out, more than a decade earlier, her husband had replaced one of the kitchen duplex receptacles and not known to remove the break-out tab. She recalled he had trouble for a while, with getting it to work, and eventually they just lived with one breaker left off. She didn't actually know that, after all, her husband was the mechanical one.

Including questions that elicited the history, it took me about 35 minutes to restore the MWBC to good order, and doubled the Watts she had for her loads. She couldn't wrap her head around that, but she was convinced that I was some kind of wizard.

 

[gar]

1812222-1300 EST

How much money are you willing to spend on test equipment, and/or procedures with what you may presently have, to be able to fairly easily pinpoint the location of the problem?

.

.

 

[al hildenbrand]

1812222-1300 EST

How much money are you willing to spend on test equipment, and/or procedures with what you may presently have, to be able to fairly easily pinpoint the location of the problem?

In my opinion, the best method is to elicit the history known to the occupant. Especially in residential. The thing(s) most recently serviced or manipulated almost always are the key that unlocks the mystery.

 

[retirede]

My brother in law had this condition in his home. Wiring was all EMT which makes me believe it should have been wired by a competent electrician. There was a handwritten note inside the door “ turn off both 11&13 for bedroom outlets”. The handwriting matched the panel schedule.
Appears that the cross connection happened during original construction and they either couldn’t figure it out or just didn’t bother.

 

[Dennis Alwon]

Disconnect it too, no?

-Hal

That is what I said in the second post. No testing just cap off one wire from one of the breakers... That is assuming 2 circuits are not needed. In that case go to the middle of the circuit and disconnect one set of wires.

 

[LarryFine]

There was a handwritten note inside the door “ turn off both 11&13 for bedroom outlets”.

Weird: opposing lines (phases).

 

[Dennis Alwon]

Weird: opposing lines (phases).

I suspect the panel is labeled differently and it is the same phase otherwise it wouldn't work or 1 would be in a constant trip condition .

 

[kwired]

Weird: opposing lines (phases).

Might just be a true MWBC from when handle tie wasn't required and not a circuit fed from two poles on same line.

 

[retirede]

Weird: opposing lines (phases).

It’s been a while since I saw this...The breakers were not next to each other so I probably (definitely) got the numbers wrong.