Questions regarding 240v outlet

Page 1 of 2  

Hello,
in my home are a few 240v outlets that used to serve air conditioners. We now have a central air system, so those outlets are no longer needed.
Can i leave the 240v outlets as is and plug any old device into them? For instance, if i were to plug my alarm clock into that outlet, what would happen?
How can iconvert them to 120v outlets? is it simply a matter of using only one of the two hot wires to wire a new 15 or 20 am outlet?
thanks much
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Is there a neutral wire at those outlets, or just the 2 hots? You'd need neutral for 120V.
--
6 days until the winter solstice celebration

Mark Lloyd
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I don't know yet as i haven't opened them up. Assuming there is, i can simply arbitrarily select one hot and the neutral wire those two to the new 120v outlet, correct?
Going back to my other question, what if i plugged an alarm clock into that 240v outlet as it is today, would that do any harm?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
farseer wrote:

The plug should not fit. If you forced it somehow, the clock would almost certainly be destroyed, perhaps spectacularly.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form snipped-for-privacy@prodigy.net.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Only to your alarm clock, and maybe to the house.
Those will burn up.
Don't forget not to try to use your electric razor in Europe either, unless it has a switch to set it for 240.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
mm wrote:

A very large percentage of recent product have auto ranging power supplies that are happy with 100-240V 50/60Hz. With these all you need to worry about is plug adapters.
Pete C.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mark Lloyd wrote:

If you're changing to 120V, you can repurpose the other hot as your neutral (suitably marked of course). Indeed if this is a single run that served a window A/C it's probably 12/2 w/ ground with the white wire tagged black or red with tape.
Pete C.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Years ago I plugged my electric razor into a 240v outlet in Israel. It immediately went up in a puff of blue smoke. I expect your clock would meet a similar fate.
Does the outlet have 3 holes or 4? If 3 (which is almost certain to be the case) you have no neutral and cannot use it for anything but devices that need pure 240v. If 4, you could use it as the basis for a multiwire circuit.
BUT, if 3 you can pull replace the 240 breaker with a 120v breaker; and put the left over hot (hopefully a white wire) into the neutral bus. You will now have, as soon as you replace the outlet with a 120v outlet, a 120v circuit! Obviously you have to be certain that you replace all the 240 components with their 120v counterpart, and that you get everything sized properly, but it is not difficult.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Check the AC input to the alarm clock. If it can accept 100V - 240V you should be ok. If not you will probably damage it with 220V.
[/quote] ___________________________________ Home Improvement Forum http://www.spicyhome.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
cannot be done safely. breaker and wire and outlet must all match. alarm clock would normally trip a 15 amp breaker. but even with an adapter, improperly feeding large available amperage into a low wattage device is tempting a fire when the alarm clock fails.
farseer wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I do my own electrical work except for three-phase (240v).
Within the last two years, I knew the line going to my dryer was problematic. It was just a matter of replacing the line from the box to the outlet - less than 40 feet. I paid someone to do it. That's how afraid I am about three-phase.
Electricity kills people and burns down houses. If you do not respect it, you could die from either the shock or smoke inhalation.
Dick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dick Adams wrote:

You should consider ceasing to do your own electrical work . At least until you learn what "three phase" means.
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Well, the wire can be heavier than it needs to be. And the wire and breaker can both be heavier than the outlet will allow to be plugged in.
After all we plug an 11 amp Hoover vacuum cleaner into the same outlet

Huh? I don't think he will know that you're kidding.

If 20 amps will start a fire, 15 amps can probably do so too.
After all we plug an 11 amp Hoover vacuum cleaner into the same outlet we plug a 1/10 of an amp radio. And that could be a 15 amp outlet or a 20 amp outlet. Any of those appliances could some day have a short.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No. (Duh.) You can plug a 240V device into them.

*If* you can get the plug into the receptacle -- which is doubtful, since the prong configurations are complete different -- the result would be a loud "POP" accompanied by a bad smell, smoke, and possibly flame.
Oh -- the alarm clock won't work any more, either.

Call an electrician. Please. You don't even begin to realize the danger you could be creating. At a bare minimum, at least go to a library or a home center (like Home Depot or Lowes) and get yourself a book on residential electrical wiring. Electricity is dangerous to those who don't understand it, and (no offense intended) your questions show that you're in that group.
--
Regards,
Doug Miller (alphageek at milmac dot com)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You can not plug a 120v plug into a 240v receptacle unless you physically take a pair of pliers or something and bend.
If there is a neutral there you can change the receptacle out to a 120v receptacle but would also need to change the breaker to a single pole breaker. Just have to figure out which hot to use.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tazz wrote:

Or change it to a split-wired duplex receptacle.
You'd still have to change the breaker to the appropriate amperage though.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Nonsense.
Breakers are sized to the conductor. The ampacity of a conductor does not depend on voltage. A 20A circuit requires 12ga wire, for example, regardless of whether it's a 240V or 120V circuit.
--
Regards,
Doug Miller (alphageek at milmac dot com)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Doug Miller wrote:

You sure about that?
My reading of tables 210.21(B)(2), 210.21(B)(3) and 210.24 is that when using a given receptacle, there are limits as to the breaker amperage, regardless of wire size.
For instance, you cannot put a 15A receptacle on a 30A or higher circuit, and you can only put one on a 20A circuit if it is a duplex receptacle or there are other receptacles on the same circuit.
Motors and arc welders are excepted from the above, but that's a whole other story.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Absolutely.

That doesn't have anything at all to do with voltage, though -- and you appeared to be saying that changing from 240V to 120V would require changing the breaker to a different amperage as well, which is not the case.

Right, but that's not the same issue. I think we're talking about two different things.
--
Regards,
Doug Miller (alphageek at milmac dot com)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Doug Miller wrote:

Sorry, my bad. I had assumed that the original circuits were heavier-duty than 20A.
Assuming that the original circuits are 15A circuits, or 20A circuits wired with #12, then there would be no need to change out the breaker.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.