The windows in my apartment have single power outlets next to them like the one pictured below, presumably for use with window A/C units. Are these likely to be 220V outlets, suitable for use with larger units like this one? One point of evidence against is that I have used these outlets successfully with smaller window units (which I do not know to have voltage transformers) in the past.

If these are not 220V outlets, what is specially about them that requires them to be different from standard, two plug outlets?



That is a 120v outlet.

220v outlets use different shaped slots - both horizontal instead of vertical. Like this:
enter image description here The plugs and outlets are made to be incompatible with 120v ones because plugging a device into the wrong voltage outlet could cause serious damage or fire.

IF that is a dedicated circuit for the AC it can be rewired as 240v quite easily by replacing the breaker and wiring it differently at both ends, using the existing wire in the wall. It will still be limited to whatever amperage the existing run supports - probably 15 or 20 amps depending on the wire gauge.

If other things are on the same circuit you would need to run new wire from the electrical panel.

Assuming you rent the apartment (not a condo that you own) you would usually need the landlord's permission to get it changed.


Here's what you're dealing with. Disregard the top row, those are for Europe. The bottom four plugs apply in North America. Note the very significant difference in power between them, which has an impact on which large appliance they can power.
enter image description here

The power is defined by the pin shapes, not the number of outlets. Your outlet is the common NEMA 5-15 even though it's a single. You're allowed to use singles, I just show doubles in the photo to show how they are interchangeable.

The single does suggest this is a dedicated circuit. You need to investigate but if that is true, you could reuse the existing wires and change the outlet and breaker to 240V. If it's 14 gauge wire you must use the 15A outlets. If it's 12 gauge you can take your pick. You can use singles or doubles, your call.


Nope -- those are 120v. Sorry.

They're probably like that to discourage people from plugging in 2 AC units at the same time.

  • More likely to discourage plugging, say, a vacuum cleaner into the same dedicated circuit... not that people don't find ways to do it anyway. – junkyardsparkle Apr 24 '16 at 7:06

If that is a single circuit going directly to the panel you can change it to 220 by putting the neutral and the hot on a 2 pole breaker and replacing the outlet with a 220 one...Quite easy actually...Just be very sure it goes DIRECTLY to the panel and doesn't pick up any other devices.


However, if you want you can still convert the power coming out from a 120v outlet to 220v by using an external device called power converter. It is a bit of a bulky box but hey, in some cases , if you really need 220v can be a solution.

  • 7
    These work for small electronics, even some small appliances. NOT for an air conditioner. At best, if the transformer is 100% efficient, the device will draw twice the amps from the 120v socket. That is a 15 amp socket, and can probably just handle the startup current of a small 120v air conditioner. A larger one that requires 240v will not run from it, even with a transformer. – Grant Apr 24 '16 at 3:08

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