Can 240V circuit become 120V?

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Old 02-13-11, 06:06 PM
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Can 240V circuit become 120V?

The living room in the older home I'm remodeling has no overhead lights installed; only a single switched outlet. It does, however, have a 240V ceil heat box installed. I'm no longer using the ceil heat, and I'm wondering if one of the hots can be removed from the bus and used as a neutral for an overhead fixture. This might not make a lick of sense but it sounded good in my head earlier today.

Thanks in advance.
 
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Old 02-13-11, 06:59 PM
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This could be possible if the wiring method contained a grounding means. IMO repurposing a non-grounded circuit would not meet the intent of the code.
 
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Old 02-13-11, 07:06 PM
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Thanks. The home was built in the 60's and few places are grounded...thus far I have changed all switches and outlets, and removed almost all light fixtures and no grounds were installed. I believe the bathroom outlets were the exception.

Would that make any difference to this project?
 
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Old 02-14-11, 05:45 AM
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How did you go about changing out the receptacles? Did you run new wiring with grounding to them? If not, you circumvented the code as well, and corrective measures need to be done to bring it in compliance. As to the 240 volt circuit, did it have a neutral? If not, one of the hot leads can be moved from the breaker and placed on the neutral buss, but it will need to be marked with white tape on both ends to "change" its color. The other hot at the breaker will need to be placed on a single breaker, and the double you have now removed or saved for future use. What color are the wires in the ceiling box? Do you plan on switching it from a wall location? Gotta know about all the other changes you made so we can give better advice.

Mod Edit: NEC Code does no permit wies smaller then #4 to be remarked neutral AHJ may or may not allow.
 

Last edited by ray2047; 02-14-11 at 10:02 AM. Reason: Code Note
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Old 02-14-11, 06:37 AM
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Good Lord! So all the switches and outlets (basically the whole house)...needs new wire run? I just popped out the horribly old switches/receptacles and put in the shiny new.

There is no ceiling box in the living room currently (I was just going to put a J-box in the attic to splice it with the old 240V circuit). And the 240V ceil heat box does not have a neutral...two reds only. Is it a serious violation if I go ahead and change the breaker? (I understand you can't really condone anyone breaking code here). And, would a single breaker just be put into place where the double pole was or is there some other method? Either way I'd like to know.

Thanks...
 
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Old 02-14-11, 09:58 AM
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And the 240V ceil heat box does not have a neutral...two reds only. Is it a serious violation if I go ahead and change the breaker?
Wires smaller then #4 can not be remarked neutral.This wiring should not be converted to 120v. Further there is no ground and it would probably violate the narrow scope of what is allowed to be done on ungrounded circuits.

So all the switches and outlets (basically the whole house)...needs new wire run? I just popped out the horribly old switches/receptacles and put in the shiny new.
If you had a ground wire at the receptacle and used receptacles with a ground no problem. If there is no ground at the receptacle you needed to use receptacles with no ground or protect the circuit with a GFCI and mark the receptacles "No equipment ground". Switches are OK with no ground.
 
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Old 02-14-11, 10:34 AM
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Well, project canceled.

Are the "receptacles with no ground" a special kind of outlet? Would it be easier/cheaper to just change the breakers to GFCI?
 
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Old 02-14-11, 11:10 AM
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Are the "receptacles with no ground" a special kind of outlet?
They are two slot with no ground prong hole.

Would it be easier/cheaper to just change the breakers to GFCI?
Breaker is easier if there are GFCI breakers to fit your panel but the breakers may make it the more expensive way to go. If you can find the first receptacle in a circuit (the hard part sometimes) you can just use a GFCI receptacle (cheaper then a breaker) as the first receptacle and feed the rest from the load side.

You wrote earlier the ceiling box had two red wires. Is this conduit?
 
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Old 02-14-11, 11:16 AM
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thanks for the catch, Ray. I wasn't sure what size was in the attic, and should have asked.
JFS321, to further the comments already made, if you are doing this for personnel protection, use the GFCI breaker, but if for convenience to be able to use 3 pronged receptacles, then, as Ray said, run the downline receptacles on the LOAD side of the GFCI, marking all downline receptacles "GFCI protected", and "no equipment ground" with the provided stickers.
With two reds only, you can't use them for a 120 volt circuit, unless it is a #4 or larger.
 
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Old 02-14-11, 12:05 PM
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Okay guys, thanks. I don't like the GFCI's because I rarely have luck getting them to fit in the J-box. Then again, I appreciate what they do.

Just for the sake of knowing...what do you mean larger than #4? All of the wiring in the house looks to be 12- or 14-2 which is why I'm confused.
 
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Old 02-14-11, 12:38 PM
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Originally Posted by JFS321 View Post
Okay guys, thanks. I don't like the GFCI's because I rarely have luck getting them to fit in the J-box. Then again, I appreciate what they do.
It's a pretty quick job to replace the old box with a larger one. Carefully cut through the box nails with a hacksaw blade, pull the box out and slip a new deeper one back into the hole.

Just for the sake of knowing...what do you mean larger than #4? All of the wiring in the house looks to be 12- or 14-2 which is why I'm confused.
The code doesn't allow you to re-color small size wires, so if they're red they have to stay red. If it was a large (#4 or bigger) wire you are allowed to mark the wire with different color tape or paint so you could "convert" a red to a white and use it as a neutral.

Does your wiring run in solid metal conduits, corrugated metal tube or flexible cable? Based on the age if it was cable it would probably have a silvery fish scale appearance with a tar-like coating. If you have a conduit system a lot of your troubles could be avoided.
 
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Old 02-14-11, 12:39 PM
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don't like the GFCI's because I rarely have luck getting them to fit in the J-box.
One solution is to replace the box with a deeper old work box. Just cut the nails holding the box using s hacksaw blade or Sawzall and replace.

Just for the sake of knowing...what do you mean larger than #4? All of
It means if you are working with very large wires, usually not a residential branch circuit, you are permitted to re-identify a wire as a neutral.
 
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Old 02-14-11, 12:50 PM
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Okay, thanks. I was just surprised that the wire had to be that big to re-label it and thought I had it confused.

The cable sheathing is black, flexible, and mesh-looking.

I'll try a bigger box. Thanks again.
 
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Old 02-14-11, 03:34 PM
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The cable sheathing is black, flexible, and mesh-looking.
Are you saying there is a metal mesh embed under the sheathing?
 
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Old 02-14-11, 04:20 PM
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Sorry for not being clear. It's definitely all copper wire...some used in the house is what I would just call regular 'romex' and then some is copper wire with that black fabric-looking sheath. I'm pretty sure no metal is underneath. And no conduit anywhere.

Is there an easy fix for grounding the overhead light fixtures? I can get around in the attic just fine but running new wire from the box doesn't excite me much.
 
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Old 02-14-11, 05:51 PM
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Is there an easy fix for grounding the overhead light fixtures? I can get around in the attic just fine but running new wire from the box doesn't excite me much.
There really isn't a workaround. New cable is what you need. It isn't just a ground but a white wire for a neutral you need. You have neither.
 
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