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Confoozled about my kitchen... or is it my outside lighting... or both? AGH! :D

Confoozled about my kitchen... or is it my outside lighting... or both? AGH! :D

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Old 05-14-10, 07:09 PM
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Confoozled about my kitchen... or is it my outside lighting... or both? AGH! :D

I reached a point of mild frustration on my other wiring project, and decided I needed an easy victory to perk me back up. I'm sick of painting and not ready to tackle my next plumbing project, so I decided - what can be easier than swapping out a white switch for a black switch. (I'm a girl - the color of my receptacles and switches is important to me.)

Kitchen. Take the cover off a two-gang box - the switch that controls my disposal and, on a separate circuit, a plug. Disregard plug. To my knowledge, downstream of this box is only the receptacle into which the dishwasher & gd are plugged. Look in box, we have 3 sets of wires. We've got:

12-2 from source (I think). Black is nicely wirenutted to the black off the switch, and to the black of a 12-3 leading to the downstream outlet. Nice. Off of the switch is a the red from the 12-3 that runs to the downstream outlet - cool. So the one plug is always on, the other gets juiced when I flip the switch. I'll take it.

Sort of separate from all this is another 12-3. The red and the black are nutted together. The white is nutted in with the neutrals from the other two wires. A little research says that a shared neutral is OK. Correct?

I go and shut off the power to the breaker I think is correct. Come back in - there are still hot wires in the box. Hrm? I restore power to the first breaker, and turn off the one above it. Still hot wires. I turn off BOTH breakers... NOW the box is dead. That doesn't seem right to me, but... I'm not a pro.

Looking at the breaker itself, it is 20A (yay), and it says Two 1 Pole breakers. Into one there is a red wire, into the other there is a black.

So, questions:

Is this OK? That I have to turn off both breakers to shut off the wires? I guess I either have 12-3 running from the breaker to the inside box or 12-2 AND 12-3 running from the source but, regardless, shouldn't shutting off the red-wire breaker be mutually exclusive from shutting down the black-wire one? Or is there a connection in the breaker itself?

If it is not kosher, how do I fix?

If it is kosher, or I can make it kosher, and the black hot feeds the garbage disposal & dishwasher, can I put the outlet (the one we disregarded earlier, remember?) on to the red hot (which feeds 3 ceiling fan/light fixtures & 2 outlets that are outside and dry)?

THANKS!!
 
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Old 05-14-10, 07:24 PM
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Sounds like you are dealing with a multi-wire circuit. You are allowed to have multiple circuits in one box. The code rule was that if both legs of the circuit landed on the same strap a 2 pole breaker was required.
 
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Old 05-15-10, 08:50 AM
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Originally Posted by pcboss View Post
Sounds like you are dealing with a multi-wire circuit. You are allowed to have multiple circuits in one box. The code rule was that if both legs of the circuit landed on the same strap a 2 pole breaker was required.
Oooh, lingo. What do you mean by 'landed on the same strap'?

Thank you - I just googled multi-wire circuit and found a site that clarified what it is, and how it is supposed to be done, for me. Sounds like my set-up is kosher and that the only thing that isn't exactly right is that the connection between the two breaker switches isn't there, making a lay-person (me) think they are separate.

Do I have to treat these circuits any differently than other, non-shared circuits? Any load considerations since they share a neutral (I'd like to put one outlet on the circuit that doesn't have the dishwasher & disposal)?

Again, many thanks. This forum is such a wonderful resource.
 
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Old 05-15-10, 10:10 AM
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The two hot conductors of the MWBC need to be on opposite legs of the panel, otherwise the neutral can carry up to twice the current it is designed for. This would create a fire hazard. A standard two pole breaker assures that the MWBC is wired correctly.
 
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Old 05-15-10, 03:19 PM
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To my knowledge, downstream of this box is only the receptacle into which the dishwasher & gd are plugged. Look in box, we have 3 sets of wires. We've got:
dishwasher should of been dedicated. Which box did you look in? It could be the receptacle is daisy chained..

12-2 from source (I think). Black is nicely wirenutted to the black off the switch, and to the black of a 12-3 leading to the downstream outlet. Nice. Off of the switch is a the red from the 12-3 that runs to the downstream outlet - cool. So the one plug is always on, the other gets juiced when I flip the switch. I'll take it.
Need to make sure what is what. The black leading downstream sounds like its just passing on the power to the other recps (daisy chained). The red could be a switch leg for the switch or a MWBC (which if so it needs to be on a 2 POLE BREAKER..) Though it reads like its a switch leg due to the others coming on with the switch is flipped.. (must be old home) Not code for kitchen at all. Should be GFCIs and not on a switch.

Sort of separate from all this is another 12-3. The red and the black are nutted together. The white is nutted in with the neutrals from the other two wires. A little research says that a shared neutral is OK. Correct?

Red and black are tied together??? is NOT GOOD AT ALL!!

I am going to need a lot more info to help you on this one.. "Sort of separate" is not enough to really address this. Though...

Red and black are tied together??? is NOT GOOD AT ALL!!

I go and shut off the power to the breaker I think is correct. Come back in - there are still hot wires in the box. Hrm? I restore power to the first breaker, and turn off the one above it. Still hot wires. I turn off BOTH breakers... NOW the box is dead. That doesn't seem right to me, but... I'm not a pro.
Its 2 circuits and apparently a MWBC...

Really need more accurate/detailed info..

Looking at the breaker itself, it is 20A (yay), and it says Two 1 Pole breakers. Into one there is a red wire, into the other there is a black.
two 1 pole breakers???? where does it read this?? It should be a 2 POLE BREAKER by CODE. I will have to dig up the code but it is code.

Is this OK? That I have to turn off both breakers to shut off the wires? I guess I either have 12-3 running from the breaker to the inside box or 12-2 AND 12-3 running from the source but, regardless, shouldn't shutting off the red-wire breaker be mutually exclusive from shutting down the black-wire one? Or is there a connection in the breaker itself?
No it is NOT!! I need more accurate info and you need a 2 pole breaker and figure out why the black and red is tied together which makes zero since. I dont see how the breaker has not tripped.. Get more info and reply back. I will try to answer if im around.
Good luck
 
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Old 05-16-10, 05:32 PM
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Thanks for the response, SilverTattoo. At the time I wrote that, I didn't have a full grasp of what was happening. I thought I did, but went back and did some more poking around, and here is how the box was actually set up:



For the breaker - it takes up 2 spots and has a label on it. I swear it says Two 1 Pole breakers, and then there is a little chart below where it tells you what AWG to use depending on how many amps (up to 40 on the chart) you're going to run through it.

The house is old - built in 1974, so I do find things that aren't up to modern code. My understanding, though, is that the disposal and dishwasher are OK on the same circuit and that, because they are below the counter, don't need to be on a GFCI.

I did some work on the box, and it is now set up as follows:



Besides the one GFCI on the diagram, I have the 2 code-required 20A dedicated circuits in the kitchen, so - my understanding is that having this one outlet run outside isn't blatantly wrong. This resolves a couple of issues: 1) the outlet was originally on a 20A line but wired with 14AWG; 2) could have connected it to a 15A line, but would then it would not be the 20A I understand is required for kitchens; 3) provides GFCI for the downstream, outside fixtures, which was previously lacking.
 
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Old 05-16-10, 08:12 PM
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Your dishwasher and disposal will be fine sharing the same circuit.

Your circuits that are for the kitchen and dining room may only serve those locations. You would be better off running a new circuit or finding power someplace else.
 
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Old 05-19-10, 07:16 PM
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ok I see now, the red is the switch leg to the disposal, that makes since. Strange it says 2 1 pole breakers.., but yea that would indicate a 2 pole which is what you need so they are diff legs. The disposal and dishwasher are fine but my preference would be to dedicate the dishwasher and no it would not require to be GFCI protected.

All looks good and it will be fine though, I would not of put the GFI on there with the fans. I would not have any receptacles on with the lighting period if I wired that house. Now if the GFI trips the fans/lights go down with the recps. Alot of residential guys like to wire power and lights on the same circuits ( not something Im a fan on..) but this is what the case is with your house. It is prob gonna be more trouble than its worth but if your really bored I would put the fans on another circuit(lighting) and keep power (recepts/GFIs) on another. Its not "code" per say but, its a more logical approach in my opinion. If the GFI trips at least you still got lighting.

Also I noticed you mentioned the circuit was originally 14 awg? If so you must replace that to 12 awg for a 20 amp breaker (which it appears you did from the diagram). Also keep in mind when you terminate those receptacles you only get 80% of that breaker rating which would be 16 amps from a 20 amp breaker. Did you figure the ampacity of the dishwasher and disposal on a single circuit at 80%?? If its over 16amps, that want work.

Other than that its looks good to me. I think your ok but I would double check the DW and disposal.
Take Care
 
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