# Two Circuits to One Outlet



## BlueRidgeGreen (Apr 21, 2012)

Wondering if someone can explain this to me.

Shutting down backsplash outlets during a kitchen remod and we just couldn't find the breaker.......
until I pulled them and realized they were split between two circuits.
(wasn't wired to a double pole though)

Neither outlet is feeding anything and I am just wondering why this would be done.

Two outlets....each sharing the same two circuits.

Maybe they were allowing for multiple small kitchen appliances?
(why wouldn't they just dedicate each individually?)

My electrician is coming by tomorrow to wire up some undercabs and a couple recessed cans.
I'm figuring he can just take one of the circuits (the reds) from each outlet for each of the lighting runs and turn the outlets into J-boxes?


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## builditguy (Nov 10, 2013)

I've run across it before. I figured the reasoning was so they could plug in 2 devices to one outlet, but not be on the same circuit. 

Also saw it on the 2nd floor of a remodel this spring. Homeowner had disconnected it. He told me it must have been extra. He hadn't realized the top half of the outlets weren't working.


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## overanalyze (Dec 28, 2010)

I have found it a few times as well...pain in the ass when you are trying to find the circuit to kill one breaker at a time...lol. I can't say I can see the need for it ever.


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## BlueRidgeGreen (Apr 21, 2012)

overanalyze said:


> I have found it a few times as well...pain in the ass when you are trying to find the circuit to kill one breaker at a time...lol. I can't say I can see the need for it ever.


That was my feeling.

Don't really get the point of it.

Otherwise, it was a nice install.
Armored....clean panel.....everything tight...

Drove me nuts until I pulled the outlets.
My poor helper ate a decent amount of crap from me thinking he was missing breakers during the flip session. :whistling


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## tjbnwi (Feb 24, 2009)

Code (NEC, yours may not, but I doubt it) requires 2-20 amp small appliance circuits. Make sure there are still 2 SA circuits. You can't put anything else on the SA circuits. 

Code also requires the panel to be properly labeled.

Tom


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## BlueRidgeGreen (Apr 21, 2012)

tjbnwi said:


> Code (NEC, yours may not, but I doubt it) requires 2-20 amp small appliance circuits. Make sure there are still 2 SA circuits. You can't put anything else on the SA circuits.
> 
> Code also requires the panel to be properly labeled.
> 
> Tom


I'm not sure what else is going on with the other couple outlets in the room. I didn't bother to check.
I'm just going to let my guy deal with it.
His father is a retired Electrical Inspector/Electrical Contractor. From the way he operates.......I think he probably knew the codes before he knew his ABC's.


If I had a nickel for every properly labeled panel I've come across....
I'd have about ten cents in my pocket. :laughing:


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## tjbnwi (Feb 24, 2009)

BlueRidgeGreen said:


> If I had a nickel for every properly labeled panel I've come across....
> I'd have about ten cents in my pocket. :laughing:


Must be you east coasters. 

Tom


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## Tom M (Jan 3, 2007)

Yep pretty common to not have the dam panel labeled on older work.


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## EricBrancard (Jun 8, 2012)

Tom M said:


> Yep pretty common to not have the dam panel labeled on older work.


Or fully labeled but completely inaccurate. That's my favorite.


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## GettingBy (Aug 19, 2010)

Kitchens draw heavy loads. 
If I understand you correctly, with a kitchen duplex receptacle wired to two breakers [one for each outlet] you could have a kitchen draw twice as much current with the same amount of receptacles.
But because of demand factor I can't imagine each outlet in a house needing to be on it's own breaker.

At the other end you may need many outlets on a single breaker for many appliances that each draw very little current.


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## Texas Wax (Jan 16, 2012)

GettingBy said:


> I can't imagine each outlet in a house needing to be on it's own breaker.



Seen switched top plugs and constant power bottoms, Rare and possibility of separate circuits. LOL Don't have to have a light switch on to watch TV


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## tedanderson (May 19, 2010)

Typically you need this type of setup if you are using those big stainless steel coffee urns as they tend to pull quite a bit of current. Having the split receptacle allows you to put a regular urn and a decaf urn side-by-side without having to drape extension cords over to another outlet on a different circuit. Then it probably branched over to another duplex receptacle to facilitate smaller appliances that could share whatever amperage was left over.

Maybe the previous owner hosted large breakfast or dinner parties where they served quite a bit of coffee and toast.


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## Michael217 (Apr 23, 2011)

The NEC requires two small appliance circuits for the kitchen area. Also required is for both circuits to be identified and either be on a two pole breaker or have handle ties. 

What was described is called a multiwire branch circuit, MWBC. It is installed with just 3 wires not 4. One less wire, only one cable if using romex, and save installation time and effort. 

Couple of ways to install them. One circuit to top half of receptacle and one on bottom, which can serve two heavy appliances on one duplex receptacle. Or, one circuit to every other receptacle.


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## Inner10 (Mar 12, 2009)

Split 15A receps were the norm here in kitchens for a long time.


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## Tinstaafl (Jan 6, 2008)

Michael217 said:


> Also required is for both circuits to be identified and either be on a *two pole breaker or have handle ties*.
> 
> What was described is called a multiwire branch circuit, MWBC.


Never heard of that requirement unless it is indeed a MWBC. The OP isn't clear whether that's actually the case.


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## CarpenterSFO (Dec 12, 2012)

I've seen it a few times, the purpose being to allow a couple of high-draw appliances in the same location.


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## AustinDB (Sep 11, 2006)

that's a smart idea in a commercial setup church kitchen. It's hard to appreciate until you get 15 crock pots full of chili plugged in and trying to balance the loads


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## BlueRidgeGreen (Apr 21, 2012)

Tinstaafl said:


> Never heard of that requirement unless it is indeed a MWBC. The OP isn't clear whether that's actually the case.


It is definitely a MWBC.

No double pole linking them though.

3 wired just like Micheal described.


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## Tinstaafl (Jan 6, 2008)

Oh, didn't catch the mention of red wires.

Using the outlet boxes as j-boxes is fine (as long as you don't exceed fill limits), but you still need to keep the MWBC as is to meet the code requirement for two circuits serving your small appliance outlets. And tie them in to a double breaker.

Your electrician is most likely going to do that and run a separate circuit for the lights. Much simpler than rewiring everything.


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## Michael217 (Apr 23, 2011)

Tinstaafl said:


> Oh, didn't catch the mention of red wires.


NEC doesn't require "red" wires.


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## Michael217 (Apr 23, 2011)

Tinstaafl said:


> Oh, didn't catch the mention of red wires.


NEC doesn't require red wires.


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## hdavis (Feb 14, 2012)

Michael217 said:


> NEC doesn't require red wires.


3 conductor (red wire) is a tip off - that's how these are done.


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## avenge (Sep 25, 2008)

tjbnwi said:


> Must be you east coasters.
> 
> Tom


Well here in the Midwest they must be illiterate, panels are rarely marked at all if they are they're either wrong or might as well be in a foreign language.


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## CarpenterSFO (Dec 12, 2012)

avenge said:


> Well here in the Midwest they must be illiterate, panels are rarely marked at all if they are they're either wrong or might as well be in a foreign language.


I'm just finishing a couple of hours of figuring out a couple of panels. It's a 2-family building, and not only are the labels wrong, but some of the branches supply lights and receptacles in both homes. Worse in that regard than I've ever seen before.


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## hdavis (Feb 14, 2012)

Labels I can handle, as long as the pretty panel and newish wire isn't tape spliced in the wall to K&T.


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## BlueRidgeGreen (Apr 21, 2012)

How bout this for a nice kick in the nuts.....?

After all these years, I just learned a new hard lesson.

My electrician was delayed by a few days, we were moving along at a really fast pace (fixed price motivation), and had all our appliances already on site.

My two laborers had nothing to do, so I had them bring in all the appliances and we hooked them up so the clients could start the transition to the new kitchen, from the temporary one set up in the living room.

Everything was just hunky dory for four days.....everything copacetic.
Then I had them bring in the fridge after I built the new surround.

Someone hears a POP!.....two bulbs blow in the recessed cans, three undercab LED's fry (temporarily plugged into the backsplash outlets), and I later realize..........the compressor on the new fridge got whacked too. 

I didn't really have time to hear the detailed explanation.....but it turns out that the way it was wired up was far crazier than I had ever imagined, and something about hooking up all those new things caused a 220 surge through both of the circuits.

Very expensive lesson.......there goes all that sweet fixed price profit. 

I feel like I should have known better than to move forward without my electrician having sussed it all out beforehand.......but it worked for 40 years before me, and four days during the remodel.

Appliance guy comes Monday.
I'm hoping there is some kind of relatively inexpensive (not $1,500) relay (?) or something that took the beating so I don't have to come out of pocket for a new compressor....or a new fridge.


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## hdavis (Feb 14, 2012)

Sorry to hear about the bad ending to a good week. Trusting existing circuits usually doesn't bite you that badly. I'd be interested to know what caused it once your sparky has a look - learning from others, and all that.:whistling


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## BlueRidgeGreen (Apr 21, 2012)

hdavis said:


> Sorry to hear about the bad ending to a good week. Trusting existing circuits usually doesn't bite you that badly. I'd be interested to know what caused it once your sparky has a look - learning from others, and all that.:whistling


He came by and fixed whatever it was.

I was so busy that day I barely had time to listen to the diagnosis.

All I remember is "this chit is a mess.....never seen anything like it.....what the heck were they thinking.....blah, blah blah.......220"

I'm going to call him soon and have him explain it to me like I'm a five year old (because in this case....that about describes my level of understanding).

I still can't get my head around why it was fine for four days until the fridge got plugged in.


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## Michael217 (Apr 23, 2011)

That's a tough current flow to follow there Blue, but I'll try to explain. 

The loads that were plugged in were connected to a multi-wired branch circuit. If a neutral is loss/opened alone this type of circuit the loads will see up to the voltage capacity of this circuit which would be 240 volts. 

It appears that once the refrigerator was connected to the circuit is when the neutral was compromised.

In a normally operating MWBC the loads are connected in parallel. If the neutral is loss the loads then become connected in series.


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## BlueRidgeGreen (Apr 21, 2012)

Michael217 said:


> That's a tough current flow to follow there Blue, but I'll try to explain.
> 
> The loads that were plugged in were connected to a multi-wired branch circuit. If a neutral is loss/opened alone this type of circuit the loads will see up to the voltage capacity of this circuit which would be 240 volts.
> 
> ...


That explains a lot.

Not that I entirely understand the "why" of it, but that is what I believe my electrician mentioned.......something about the neutral.

I think he said something about power "returning" along the neutral path......blah...blah...blah.....?????
(I really need to pay more attention....this chit is so confusing to me for some reason)


Any insight into why it would have survived without incident for that long and then suddenly decided to surge?

How would the fridge "compromise the neutral"?

Thanks for the tutorial ....i appreciate it. :thumbsup:


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## Michael217 (Apr 23, 2011)

BlueRidgeGreen said:


> That explains a lot.
> 
> Not that I entirely understand the "why" of it, but that is what I believe my electrician mentioned.......something about the neutral.
> 
> ...


I don't think it was the refrigerator that caused the problem. I think it was when the unit was plunged into the receptacle that broke open the neutral. Could have been a loosely spliced neutral and the pressure of pushing in the refrigerator plug broke open the connection.


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## Michael217 (Apr 23, 2011)

BlueRidgeGreen said:


> I think he said something about power "returning" along the neutral path......blah...blah...blah.....?????
> (I really need to pay more attention....this chit is so confusing to me for some reason)


Don't feel bad at all. The electrical "flow" of current in a MWBC is confusing to experienced electricians.


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## maninthesea (Nov 11, 2008)

I had something similar whole house, The Neutral was bad connection on the utility side. Normal operations in the house the loads were pretty much balanced but there was one larger load(I forget what) that would throw off the balance and some lights would dim, others go bright, some fans speed up others slow down. 

voltage would allways add up to 220 but might be 165 on one leg 55 on the other.

I am guessing the fridge unbalanced the circuit.


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## C'est Moi (Jun 6, 2015)

I realize I am late on this but what the op described is not a multiwire branch circuit simple because the receptacle was not de-energized by a single breaker. I may be reading it wrong but that is what it sounds like. You probably have a branch circuit loop where the receptacle is fed twice by a breaker on the same phase. 

If 2 circuits were feeding one receptacle then it would blow the breaker with a 240v short unless they were on the same phase. Now if the receptacle were a split receptacle that would be different however that is not what was described in the first post.

I didn't read every post so I may have missed something. Also in order for it to be a multiwire branch circuit then you would have a 3 wire cable-- white, black, and red, and fed from 2 phases.

Here is the nec definition of multiwire branch circuit



> Branch Circuit, Multiwire. A branch circuit 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
> ...


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## philcav7 (Jan 15, 2009)

Michael217 said:


> That's a tough current flow to follow there Blue, but I'll try to explain.
> 
> The loads that were plugged in were connected to a multi-wired branch circuit. If a neutral is loss/opened alone this type of circuit the loads will see up to the voltage capacity of this circuit which would be 240 volts.
> 
> ...


Can you dumb this down for me a bit? I'm aware of this issue, but can't visualize how taking the nuetral out creates 240V to the outlet. I've never done this on a single receptacle, but it's not uncommon to have a mwbc feeding multiple areas of a kitchen. 

Is there a diagram somewhere that can illustrate the open neutral problem?


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## C'est Moi (Jun 6, 2015)

See if this helps. It is a common problem when the utility looses a neutral and destroys all the electronic in the house


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## philcav7 (Jan 15, 2009)

Looks like it becomes a series circuit?


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## mrcharles (Sep 27, 2011)

EricBrancard said:


> Or fully labeled but completely inaccurate. That's my favorite.


I think they teach apprentice electricians that you never properly label a panel 100%.... I just had my electricians who I've know for 15 years install a new panel and handle some issues in my house and they did a great job..... but they labeled the A/C Range.. I have a gas stove


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## BlueRidgeGreen (Apr 21, 2012)

BTW....

This thing is still an ongoing PITA.

Finished up a month ago...or more. Client is still using old fridge out on the deck.

Appliance tech screwed up and then told the client that our new dedicated fridge outlet is bad. No ground.....something. Can't even fathom how that is possible. Straight run from the panel, new breaker, new everything. 

Going back out with my electrician to deal with it.

Did I mention the $500 Blanco faucet that I went back 5 times to try and fix.......and ended up just having to get a replacement because the original was bad?
I have to install that thing too. And...regrout because the leaking killed my fresh urethane near the sink.

I'm over eating chit sandwiches because of ghosts. Why won't they just let me close this out and be on my way?


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## hdavis (Feb 14, 2012)

BlueRidgeGreen said:


> Appliance tech screwed up and then told the client that our new dedicated fridge outlet is bad. No ground.....something.



Pretty tough to miss a ground. I've seen AFCI breaker trips on fridges, though.


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## BlueRidgeGreen (Apr 21, 2012)

hdavis said:


> Pretty tough to miss a ground. I've seen AFCI breaker trips on fridges, though.


That's what I was thinking......

and I was right.

The appliance tech was trying to cover his ass for diagnosing the compressor mother board as bad and not realizing the compressor was shot too. The clients waited a month for the replacement mother board.....and the fridge still didn't work.

Our outlet was 100% rock solid.

I brought my electrician back as a cheap insurance policy (and because I ain't no Thomas Alva), and he confirmed that it was perfect.


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