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Discussion Starter #1
Hi,

I'm having an issue in my attached garage where if I'm running my dust collector, the circuit usually blows when it starts up. What I would like to do is add a "split" outlet do the junction box. I think that's what it's called. So basically, I can have two dedicated 20 amp circuits going to that box. Before I do this, I was hoping somebody can verify that what I'm doing is correct.

I have a HomeLine load center with "HOM" type breakers. I'd get a 20 amp double-pole breaker. Run another 12 gauge wire to the outlet, break the tabs off, and that's it.

I can do this because the existing neutral and hot wires are 12 gauge, and I only need to add a third and I can share the neutral. I can share the neutral because in the circuit break box, when you have a double-pole breaker, since they are right next to each other, they use different legs of the alternating current. So essential, you would never have more than 20 amps on the neutral because the electricity is constantly alternating. You would use a double pole breaker because if somebody wants to turn the power off to that outlet, they won't be surprised to see the other half is still live.

So before I do anything, I wanted to run it past the experts here to see if I'm correct or not. I've done electrical work in the past, but I'm no expert.

Thanks!!
 

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Licensed electrician
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You would only be able to run a new single wire if you had a conduit system. If you have a cable you would need to new a new cable.
 

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Master Electrician
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As Jim said. Then there’s the GFCI requirement with your proposed set-up.

If the wiring method is cable, I’d just pull a new cable from the panel as a dedicated line and use a 20A GFCI receptacle. Then you wouldn’t need a 2-pole breaker, just a single pole.
 

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A "Handy Husband"
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A circuit as you describe with a shared neutral is a MWBC (Multi Wire Branch Circuit). All wires of a circuit must be in the same cable. Run a new 12-3 cable.

OR (here I go again Jim Port):)

Run a new 12-2 cable, break the tabs on both sides of the receptacle, terminate both the hot and neutral leads separately on the receptacle. Feed both of these circuits from a 2 pole breaker so that both turn off at the same time.

If you have conduit, forget all I have said.
 

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Licensed electrician
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A circuit as you describe with a shared neutral is a MWBC (Multi Wire Branch Circuit). All wires of a circuit must be in the same cable. Run a new 12-3 cable.

OR (here I go again Jim Port):)

Run a new 12-2 cable, break the tabs on both sides of the receptacle, terminate both the hot and neutral leads separately on the receptacle. Feed both of these circuits from a 2 pole breaker so that both turn off at the same time.

If you have conduit, forget all I have said.
Now all they need to do is add the GFI protection to a split wired receptacle.
 

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Master Electrician
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Garage receptacles require GFCI protection. The 2-pole breaker would have to be a GFCI breaker to be able to do a split receptacle.
 

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Discussion Starter #7
OK, thanks for the info. I failed to mention that I have EMT and not romex.

SD515 also made a good point too. This *is* a GFCI outlet. I didn't research this, but something makes me think that if two hots feed a GFCI with one neutral, it will constantly be tripping/not work.

I'd like to upgrade my electrical in the garage because I am starting to expand my workshop. I didn't want to go the subpanel route yet, and thought that maybe a split outlet / MWBC might be a band-aid fix until I can get a subpanel. However, with the GFCI's and two neutrals, it might just be easier to run a new conduit for the circuit. But if I do that, I'd rather just get the subpanel and be done with it.

Thanks all for the info. You guys made a great point about the GFCI and something I forgot. Now, just for my own knowledge, if it wasn't a GFCI receptacle, was I correct in explaining everything?

Thanks!!!
 

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Discussion Starter #8
HOLY COW! :eek:

A 20 amp double pole GFCI breaker is 211 bucks at our local home improvement store, Menards. Even if it was 100 bucks for the breaker, I don't think I would get it.

Back to the drawing board...
 

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Master Electrician
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What type of box is the receptacle mounted in now? Single gang? 2 gang? Surface or flush mount? Can you change the box easily or pipe out of it to a new location?

If you can stay within box fill and conduit fill limits, you can pull new wires from the panel for a new receptacle through the existing pipe.

 

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Licensed electrician
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What type of box is the receptacle mounted in now? Single gang? 2 gang? Surface or flush mount? Can you change the box easily or pipe out of it to a new location?

If you can stay within box fill and conduit fill limits, you can pull new wires from the panel for a new receptacle through the existing pipe.

If you have room in the conduit for the additional conductors I would mount another GFI next to the other GFI in a 2 gang ring.
 

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Master Electrician
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That's what I was thinking Jim. If it's a 4 square box, use a dual decora type raised cover for 2 GFI's.
 

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A "Handy Husband"
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Now all they need to do is add the GFI protection to a split wired receptacle.

You Got Me:)

2 pole GFCI (Big$$$$)


Add a new circuit and a new receptacle next to the existing receptacle.
 

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Discussion Starter #13
Thanks all for the information and ideas.

I think I might try to figure out where the conduit goes and take it from there. I checked, and it's 14 gauge wire, so I'd have to replace it for 20 amp. So many options...


thanks again for the help!!!
 
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