# Converting a 30 Amp 120/240V circuit into two 20 Amp 120V circuits



## k_buz (Mar 22, 2012)

I find nothing wrong with any of your ideas. It all looks good. As of the 2008 NEC you would need to install a 2P breaker or two single pole breakers with a handle tie for a multi-wire branch circuit.


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## frenchelectrican (Apr 12, 2006)

I know you say Red , Black , White but where is green or bare ground conductor ? if so you are good to go.

( Let us know if you do ran this in the EMT conduit that will useally a big plus ) 

Merci,
Marc


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## sixspeed (Apr 11, 2012)

What is the NEC reasoning for requiring 2P/tied breakers when the circuits are serving two physically separated 120v appliances? 


The 10/3 cable is actually an armored metal cable with no separate bare ground. I would attach it to a metal junction box, then bond a pigtail to the box and tie all the bare grounds from the new cables to the pigtail.
Thanks for the clarifying the details.


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## Techy (Mar 16, 2011)

because if you only turn one hot of a mwbc off, the neutral is still carrying current, and can shock you.


If this is actually an armored cable, and there is no 'bond strip' (usually folded back at the end of the cable), then you do not have a functional ground per the NEC.


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## Jim Port (Sep 21, 2007)

Sound like this is in a kitchen so it would require GFI protection also.

You could just add the junction box and add a 2 gang cover plate.


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## rrolleston (Oct 17, 2011)

If you don't have a proper ground then you could use a 30 amp single pole breaker and use 30 amp 120v circuit. Either way since 10 gauge is such a pain to work with I would install a small outdoor panel and use smaller wire with GFCI breakers for everything except the fridge.


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## stickboy1375 (Apr 28, 2012)

rrolleston said:


> If you don't have a proper ground then you could use a 30 amp single pole breaker and use 30 amp 120v circuit.


What would this accomplish?




rrolleston said:


> Either way since 10 gauge is such a pain to work with I would install a small outdoor panel and use smaller wire with GFCI breakers for everything except the fridge.


That is just crazy, why install a panel when he can just install a jbox and accomplish the same exact thing?


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## stickboy1375 (Apr 28, 2012)

sixspeed said:


> I presently have a 30 Amp 120/240V dedicated circuit that powers a mini kitchenette appliance with two electric stove burners and a small refrigerator. I would like to remove this all-in-one appliance, and in its place, install an undercounter refrigerator and cabinet/wall mounted microwave.
> 
> Can I take the 30 Amp 120/240 circuit and split it into two separate 20 Amp 120V circuits?
> 
> ...


This is all acceptable, just change out the breaker to a double pole 20 and you're good to go.  I would just verify that the existing 10-3 cable does in fact contain a bonding strip inside...


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## rrolleston (Oct 17, 2011)

That is just crazy, why install a panel when he can just install a jbox and accomplish the same exact thing?[/QUOTE]

Disregard what I said.

I was thinking outdoor kitchen. I have many people thinking about those and had that on my mind at the time.


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## stickboy1375 (Apr 28, 2012)

rrolleston said:


> That is just crazy, why install a panel when he can just install a jbox and accomplish the same exact thing?


Disregard what I said.

I was thinking outdoor kitchen. I have many people thinking about those and had that on my mind at the time.[/QUOTE]


HEHE, i was hoping your mind was somewhere else.


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## Lesha22 (May 3, 2015)

I am trying to do the same thing except
I have 10/3 with ground. Red, black, white, bare.

Do I tie all the grounds together (3 of them)? 

Then...Do I attach a pigtail to that and attach pigtail to the metal box?


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## Jim Port (Sep 21, 2007)

Yes, splice all grounds together and to the box if metal.


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## Lesha22 (May 3, 2015)

What is the purpose to attach the pigtail ground to box?


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## Jim Port (Sep 21, 2007)

To ensure the box is grounded.


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## Lesha22 (May 3, 2015)

I will do that.

The box is in a place where there is no chance of anyone every touching it or reaching it without a very tall ladder.

Do you always need to ground the box, or only when you split one circuit into 2. For example when you extending one 120v line?


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## Jim Port (Sep 21, 2007)

All metal boxes need to be grounded.


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## Tom738 (Jun 1, 2010)

Lesha22 said:


> I will do that.
> 
> The box is in a place where there is no chance of anyone every touching it or reaching it without a very tall ladder.
> 
> Do you always need to ground the box, or only when you split one circuit into 2. For example when you extending one 120v line?


The problem isn't just somebody touching it; it's having a hot touch it from the inside and then having the current find its own path through the rest of your house back to the neutral, however that happens. Grounding the box makes that much less likely for any significant amounts of current. In any event, code isn't really about whether your particular installation is safe, it's about whether a particular practice will make installations safer on average.


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## Lesha22 (May 3, 2015)

so If you put a nut on (correct size) and electrical tape it. how does a hot touch anything?


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## Jim Port (Sep 21, 2007)

A hot should not touch the box. However, if it does, a low impedance path back to the panel is needed to trip the breaker. This is why the metal box is grounded.


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## Lesha22 (May 3, 2015)

So in EVERY junction box all the grounds are spliced together and pigtailed to the box?


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## Jim Port (Sep 21, 2007)

Yes, as long as the box is metal. If plastic, there is no need to bond to the box.

Regardless, the grounds need to be spliced.


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## Lesha22 (May 3, 2015)

Just So I understand completely.

I have 2 seperate junction metal boxes about 12 feet apart that extends 3 wires.. TWO 12/2 and ONE 14/3.

I connect white to white, black to black, red to red, and all the ground together and pigtail to box or separate ground to ground for each and pigtail to box?


Thanks for all your help Jim!!!


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## Jim Port (Sep 21, 2007)

One pigtail to the box is enough and spliced to the other three grounds.

If the 14-3 comes from the panel the maximum breaker you can use is a 15 amp two pole.


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## Lesha22 (May 3, 2015)

so I would need to get a nut that can handle FOUR 12/2 and TWO 14/3 grounds and pigtail.

pretty big one i guess.


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## Jim Port (Sep 21, 2007)

You will have one wire nut for the 4 grounds, one for the three whites, and two for the black to black and black to red.


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## Lesha22 (May 3, 2015)

Now I'm confused... i have 4 separate breakers for each of the 3 wires.

2 - 12/2 wire with a 20amp breaker for each wire. (black, white, ground)

1 - 14/3 wire with 2 15amp breakers (which are not connected when house was build, but I know need to fix so they have 1 handle). (black, red, white, ground)

i just need to extend them because they are not long enough to where I need them. (~ 12 feet)

why would i connect red to black anywhere?


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## Jim Port (Sep 21, 2007)

I thought the 14-3 was being split into the two 12-2 cables.


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## Lesha22 (May 3, 2015)

lol. that is a different issue. it was 10/3 30amp/240v and is now completed. 

now i'm onto this extending part, and what to do with all the grounds..


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## Jim Port (Sep 21, 2007)

An 8 port push in connector would be the easiest way to make those connections.


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## Lesha22 (May 3, 2015)

I don't know how comfortably I feel with them? do you also need to electrical tape them?


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## jbfan (Jul 1, 2004)

Lesha22 said:


> I don't know how comfortably I feel with them? do you also need to electrical tape them?


No tape required.


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## Lesha22 (May 3, 2015)

can the wires ever come out by accident?


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## Lesha22 (May 3, 2015)

i cant find and 8 port that accepts #10 wire...


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## tylernt (Jul 5, 2012)

> so I would need to get a nut that can handle FOUR 12/2 and TWO 14/3 grounds and pigtail


When you have too many connections for one nut, just use jumpers (6" length of wire). For example, red wire nuts will accommodate four 12ga wires, so put three wires and a jumper under one red nut, then under a second nut, put your jumper and the final 12ga wire and the two 14ga wires. If you need to bond a metal junction box, use a "greenie" with an extra-long ground poking out the top, or make a rabbit ear with one of the grounds around the ground screw as that wire enters the box.


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## Jim Port (Sep 21, 2007)

Lesha22 said:


> i cant find and 8 port that accepts #10 wire...


http://www.idealind.com/prodDetail.do?prodId=in-sure&div=0&l1=push-in


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## Lesha22 (May 3, 2015)

Jim,

as an licensed electrician you fee comfortable with these over regular nuts?


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