120V to 240V Plug Adapter, or rewire?

This is definitely not a DIY question.

There is a 240V outlet under a window where an AC unit with a 120V plug should go. Is it advisable to use an adapter, or should I have the outlet rewired?

If the latter, can you recommend an electrician for this and a couple of other small projects? I left a message for Preferred, MOL advertiser.

What voltage does the outlet provide? An adapter will not change that. If you plug a 110V appliance into a 220V outlet, even with an adapter, you are likely to ruin the appliance. If it is 220V, get an electrician.

Tom is right.  That needs to be rewired to work at 110 volts.  If it is a dedicated circuit it isn't that tough.

Not sure what voltage the outlet provides -- I've never used it. It is the only such outlet in the house, which was rewired in the last 12 or so years when the kitchen was renovated.

My electrician will answer this for you over the phone first thing tomorrow, I think, no charge and no obligation. Superior Wirework, 973-713-5345. Ask for Dan.  I tend to be overly cautious about issues "inside the walls," namely plumbing and electric, so tend to go straight to a pro when I have a question or concern!

Tom_Reingold said:
What voltage does the outlet provide? An adapter will not change that. If you plug a 110V appliance into a 220V outlet, even with an adapter, you are likely to ruin the appliance. If it is 220V, get an electrician.

Allow me to ask a super dumb question. When I travel to Africa, I use an adapter to plug in most of my devices. Hairdryer, flat iron, etc.. I just assume that’s what people who use non-conforming devices do. What is the adapter for? Is it not to reduce voltage? Besides allowing me to plug in, since the configuration of the socket is different? 

A plug adapter -- the kind you use for a phone charger, for example -- merely lets you plug into an outlet with a different configuration. It doesn't change the voltage. To change the voltage, you need a converter or a transformer.

In the US, 240V (AKA 220V) means the following: i.) first conductor, usually black, carries 120V+;  ii.) second conductor, usually red, carries 120V+; and iii.) third conductor, usually white, carries negative charge back to the breaker box.  Newer installations have a fourth wire ("iv") which is usually green and is a backup wire for the third wire.  The 240V designation is made by addition of the voltage of conductors "i" and "ii" (although, 240V+ is NOT present - instead, two 120V+ conductors are present).  

In comparison, a "normal" modern 120V US outlet has three conductors as follows: "i", "iii" and "iv"  (black conductor with 120V+, white conductor carrying negative charge and green wire for backup ground which wires to the third prong on 120V outlet).

Conclusion:  your "240V" outlet can easily be rewired to 120V (I would recommend that you use an electrician in light of your unease with electrical installs).  Alternatively, "adapters" are made to convert a 240V outlet to 120V.  See https://www.homedepot.com/p/Tasco-30-Amp-Receptacle-TT-30R-to-15-Amp-Plug-5-15P-16-00553HD/302621518?MERCH=REC-_-PIPHorizontal2_rr-_-301132551-_-302621518-_-N  Please note, there are multiple configurations for 240V receptacles.  Thus, if using an adapter, you must use an adapter where the male end matches exactly your outlet.  I would take picture of your existing 240V outlet before heading to Home Depot to find an adapter.

j_r said:
This is definitely not a DIY question.
There is a 240V outlet under a window where an AC unit with a 120V plug should go. Is it advisable to use an adapter, or should I have the outlet rewired?
If the latter, can you recommend an electrician for this and a couple of other small projects? I left a message for Preferred, MOL advertiser.

 By the way, the plug pictured in your OP can be used in various configurations.  The most common use (that I have seen) is as a dedicated receptacle for a high draw 120V appliance (such as a big microwave or an air conditioner).  Once in awhile, I have seen this receptacle used for 240V.  Most US 240V installs look like the receptacle for an electric clothes dryer.

PS If the existing cord end for this receptacle has two vertical flat conductors, then its is likely 120V.  Alternatively, if the cord end has one vertical flat conductor and one horizontal flat conductor then the outlet is likely 240V.

ElizMcCord said:
Allow me to ask a super dumb question. When I travel to Africa, I use an adapter to plug in most of my devices. Hairdryer, flat iron, etc.. I just assume that’s what people who use non-conforming devices do. What is the adapter for? Is it not to reduce voltage? Besides allowing me to plug in, since the configuration of the socket is different? 

 It depends on what kind of "adapter" you use. One kind just changes the orientation and shape of the prongs, and the other kind steps the voltage down to 110V. There are some appliances that can accept either voltage, and you can find out if your appliance adapts by reading the fine print on the plug or the appliance end of the cord. I'd be surprised that a hair dryer or iron can accept either voltage, but I don't really know.

Why wouldn't you just get a 240v air conditioner?

Steve said:
Why wouldn't you just get a 240v air conditioner?

 Because I have four working 120v units?

.

RealityForAll said:
In the US, 240V (AKA 220V) means the following: i.) first conductor, usually black, carries 120V+;  ii.) second conductor, usually red, carries 120V+; and iii.) third conductor, usually white, carries negative charge back to the breaker box.  Newer installations have a fourth wire ("iv") which is usually green and is a backup wire for the third wire.  The 240V designation is made by addition of the voltage of conductors "i" and "ii" (although, 240V+ is NOT present - instead, two 120V+ conductors are present).  
In comparison, a "normal" modern 120V US outlet has three conductors as follows: "i", "iii" and "iv"  (black conductor with 120V+, white conductor carrying negative charge and green wire for backup ground which wires to the third prong on 120V outlet).

 Just a quick question ... and written from my experience here in Australia ... is the domestic power supply in the US AC or DC?

Edited to add ... of course it's AC .. at 60Hz!

And, because it's AC, the concept of positive and negative does not exist.

Your lines will be active, neutral and earth.

See - https://en.wikipedia.org/wiki/Mains_electricity#Building_wiring

You'll only get positive and negative lines if you're operating with DC.

j_r said:

Steve said:
Why wouldn't you just get a 240v air conditioner?

 Because I have four working 120v units?

 Got it.  I assumed that it would be a new purchase.

if this is for an a/c you for sure don’t want to use an adaptor!

240 volt a/c will cool better and be more efficient than 120 volt unit

I’d say you’re much better off getting a new a/c that can use 240 volt rather than paying an electrician to re wire 

Preferred Electrical Services, MOL advertiser, got the job done lickety split, did another minor job and then helped me get a shattered spotlight out of a high hat. (Insert lightbulb joke here.)

j_r said:
Preferred Electrical Services, MOL advertiser, got the job done lickety split, did another minor job and then helped me get a shattered spotlight out of a high hat. (Insert lightbulb joke here.)

 How many online posters did it take to change the lightbulb?

Don't know, they couldn't agree on how to do it so after calling each other vile names they burned the house down instead.

Ok, I have been spending too much time online.  I need to go outside and garden now....