Replacing 240 Volt outlet with 120 Volt outlet


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Old 09-05-09, 09:13 PM
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Replacing 240 Volt outlet with 120 Volt outlet

We replaced our electric dryer in the garage with a gas dryer. Now we have a 240 Volt outlet right above the dryer, but have to run an extension cord to a 120 Volt outlet 6 feet away. We don't really need the 240 Volt outlet for now, so I want to convert it to a 120 Volt outlet.

Looking at the outlet, I see only a black wire and a white wire coming in. The ground wire just runs from the outlet to the back of the case. The wiring is all in steel tubing, running from the outlet to the house's breaker box, just 4 feet away.

Even if there is no ground wire, can I still install a GFCI outlet? Do I need to rewire at the breaker box to a single breaker instead of the current double breaker? Can I use the black wire as the hot wire and the white as neutral?

Thanks for any advice.
 
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Old 09-05-09, 09:53 PM
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If the washer is next to the dryer you can just use that receptacle.

To change over the receptacle at the dryer it would be best to pull new #12 THN or THWN since you have conduit. You probably have #10 and that would be difficult to wire to a 120v receptacle. You will need one green one black and one white.

You will need to remove the wires from the 2pole breaker and either add a 120v 20a breaker to the panel or replace the 240v breaker. If you replace the 240v breaker you will need to insert a dummy in one of the panel cover slots.

Depending on location a GFCI protected receptacle may be required.

If the box is metal and conduit metal all the way to the panel a ground wire is not code required but best practice,
 
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Old 09-05-09, 11:01 PM
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Thanks for the comments. The receptacle where the washer plugs in is about six feet away. We use an extension cord now, and I wanted to get rid of that.

I wanted to leave the heavy wiring (it does look quite heavy, probably #10 as you say), so the outlet could be converted back to 240 Volt if wanted. But it looks like that will not work well, so I'll think a little more about what to do. Maybe just leave it.

The idea of running new wire makes sense given the distance. I measured and the distance from the breaker box to the outlet is just 2 feet. The conduit is metal, and the outlet box is metal, so I guess ground is not needed. But may as well do it.

I've read some of the other posts in the forum and learned a lot. Our house was built in the 1950s, and remodeled extensively in 1989. The new part of the house has grounded wiring. But the old part does not.

I know the house next door has knob and tube wiring, so I suspect the old part of our house does too. I've never been able to get up under the roof to check.
 
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Old 09-06-09, 05:13 AM
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Is the washer receptacle surface mounted? Even if it isn't you should be able to run a second receptacle off of it for the gas dryer.
 
 

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