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2 hots and 1 neutral?

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alfredeneuman

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Neutral has been used in days gone by for dryer and (EDIT: Range) circuits, and was OK at the time.
Never AC circuits.
2 wire 20A receptacles aren't even made, and 15A receptacles don't meet the minimum.
 
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Marctrees

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OP said - "10-3 w/o ground is in use."

I have never seen a "10/3" without a ground, totaling 3 wires.

Not 4 wires as a "Normal" 10/3.

Is there such a thing ever in history ?

Marc
 

Marctrees

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OP - If you were planning to replace what you call a "220 breaker" w two single poles... thinking that makes a difference because you want 120 v ckts, you should NOT be doing this work.

Marc
 
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tipsy

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yes it's a red, black and white. Even stamped right on the jacket it says 10/3 w/o ground.
Over on "ElectricianTalk.com" forum, I just searched for 10/3 w/o ground and there are quite a few references to it. How it was used up into the 80's and early 90's and didn't change until code required 4 wire system.
I guess this was the wrong forum to ask. I thought I'd be treated with respect But I was wrong. I won't be returning to this forum.
Signing off now.
 

Citation

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OP said - "10-3 w/o ground is in use."

I have never seen a "10/3" without a ground, totaling 3 wires.

Not 4 wires as a "Normal" 10/3.

Is there such a thing ever in history ?

Marc

Not sure about 10/3 but until a few weeks back my garage was powered by a 12/3 with no ground. My guess is the setup was probably so a two way switch could turn out the garage light from the house. I have a two way switch by the back door that used to switch the garage between the black and red wire of that 12/3 wire.

Anyway, assuming the OP has a white (N), black (L1) and red (L2) wire in his 10/3, could he just set up a single 120V circuit by using the red wire as a ground (with proper marking of the wire to let people know it's a ground)?

I didn't catch if the OP needed 2 120v circuits or just figured it was an option.
 
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Citation

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So I’ve been to the house and seen the situation. 10-3 w/o ground is in use. Just wondering as I mentioned above. Can each of those hots share the one neutral. Each hot would be on its own dedicated circuit breaker.


Sent from my iPhone using Garage Journal

Ignoring the lack of ground, yes two opposite leg circuits (ie 240V apart) can share a neutral. The reason why may not be obvious but here is why. The current has to form a loop too and from the panel, out the hot leg and back through the neutral.* What happens when we add a second leg? The two hots, L1 and L2, always flow in opposite directions. So if L1 is flowing current out, L2 is flowing back to the panel.

Now consider a case where only L1 has a load. Current flows out L1 and back through neutral. If only L2 has a load current flows out neutral and back though L2. If both have the exact same load the current flows out L1 and then back L2. The current flowing through neutral is the difference between L1 and L2.


*Since this is AC voltage the direction is constantly changing but I figure it's easier to think of it as DC and just assume a constant direction.
 

Norcal

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Before using the neutral to ground the frames of clothes dryers was prohibited, 10/3 NM without ground was sold & used by ropers wiring tract homes around here, I never cared for it though.
 

Innovate1

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OP said - "10-3 w/o ground is in use."

I have never seen a "10/3" without a ground, totaling 3 wires.

Not 4 wires as a "Normal" 10/3.

Is there such a thing ever in history ?

Marc

It seems these were pretty common and there is actually an exception for just such a case in the NEC. An exception in 250.140 for dryers (and possible some other things) provided some conditions are met. Google it and you will find LOTS of hits.

As far as calling the dual breaker a "220 breaker" that doesn't seem to be that big of a stretch. That's a typical use.

I have been in places that don't have any code inspectors and crazy things get done. A few weeks ago I was helping some friends with some electrical issues in a place like that. A room was added on and for the electric in the addition they just stripped off the insulation on the romex and looped the added wire about 3/4 of the way around the existing wire and taped it up. Not even a decent twist. Their complaint was they kept tripping the breaker which was because of too many things on the circuit. I was very surprised that the connections did not appear to have heated. I put in two new circuit runs to the main panel and boxes for the proper splices.

My point is that often people that don't know how to do something just do what works even though that may not be the proper way and it could be dangerous. The OP was looking for some guidance to do it properly. Knowing what you don't know is a good thing.

It appears that since this will be 20A circuits that a ground wire could be run from a nearby 20A circuit, assuming they all feed back to the same ground point, which is most likely the case. That could save fishing a wire clear back to the panel.
 

Marctrees

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yes it's a red, black and white. Even stamped right on the jacket it says 10/3 w/o ground.
Over on "ElectricianTalk.com" forum, I just searched for 10/3 w/o ground and there are quite a few references to it. How it was used up into the 80's and early 90's and didn't change until code required 4 wire system.
I guess this was the wrong forum to ask. I thought I'd be treated with respect But I was wrong. I won't be returning to this forum.
Signing off now.

There was no disrespect.

Simply a statement saying basically... Based on things you have said you are not sufficiently knowledgeable to do this work w a guaranteed safe end result.

If that is taken as disrespect, that's your perception.

Marc
 

Marctrees

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Re the 10/3 WO grnd...

My elect work was only in MN, never ran into it there.

Maybe a regional or state thing.

We used 2 cond plus ground SE for driers, but never heard of cable w 3 insulated conductors but no ground.

Marc
 

alfredeneuman

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He asked the same question in the DIY Chatroom, and it only took 15 posts to tell him he can't do it, as opposed to here where it took 55+ posts.
Which just goes to prove that we've got more patience here
:lol:
 

6768rogues

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There is a difference between making it work and doing it correctly and safely to code. If I were doing something for compensation in a customer's house, it would be done to code or I would not do it. I would do it that way at home, too, but that is your own guilt trip if the opportunity presents itself.
 

850xpeps

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Ignoring the lack of ground, yes two opposite leg circuits (ie 240V apart) can share a neutral. The reason why may not be obvious but here is why. The current has to form a loop too and from the panel, out the hot leg and back through the neutral.* What happens when we add a second leg? The two hots, L1 and L2, always flow in opposite directions. So if L1 is flowing current out, L2 is flowing back to the panel.



Now consider a case where only L1 has a load. Current flows out L1 and back through neutral. If only L2 has a load current flows out neutral and back though L2. If both have the exact same load the current flows out L1 and then back L2. The current flowing through neutral is the difference between L1 and L2.





*Since this is AC voltage the direction is constantly changing but I figure it's easier to think of it as DC and just assume a constant direction.



Interesting. I didn’t know 2 circuits charging a neutral required to be on different legs.
 
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