Can I Convert A 120V Outlet To 240V?

There is continuous confusion about the voltages used in different parts of the world. Most of the outlets in the US use 110 volts, which is officially 120V. But how will you run appliances if they need 240 volts? Should you convert the 120V outlet to 240V or replace it?

If the 120V outlet is the only outlet in the circuit, and your panel is not full, which means you have empty breaker positions, you can convert the 120V outlet to 240V. Change the breaker to a 2-pole 240V breaker and install wires supporting 240V. If done correctly, your outlet should have 240V.

However, there are other things to understand and consider. This article will explain the possibilities of converting 120V to 240V and the conversion steps. If you cannot convert the outlet yourself, consider consulting and hiring an electrician for the job.

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Is it possible to convert a 120V outlet to 240V?

If you have appliances that need 240V outlets, you need to convert your 120V outlet to 240V.

There is no problem converting a 120V outlet to 240V, provided you have only one 120V outlet in the circuit.

Getting a 240V outlet is very simple. You need to clip a double-pole circuit to both 120 buses simultaneously.

When you do so, the circuit’s voltage doubles and converts to 240V.

You need two hot wires and a neutral wire for 240V circuits so that they can carry enough electricity to the plugged-in appliance.

Though most US people use 120V, some larger appliances like electric ranges, dryers, and air conditioners use 240V outlets rather than 120V.

Installing an outlet for these appliances with 240V is relatively easy.

Also read:

How can I convert a 120V outlet to 240V?

Most of the US adopted 120V before 1900 as their standard voltage and are still using it.

A 120V outlet can power every standard device, from small household devices to larger ones.

But, some appliances will require larger voltage, like 240V.

So, convert the voltage of the outlet to power these appliances.

Fortunately, you can convert a 120V outlet to 240V, and the procedure is quite simple.

Buying a dedicated voltage converter can also make the work easier.

Things required:

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Step 1: Turn off the power

Turn off the power at the breaker and also the main breaker.

Sometimes, turning off only the breaker of the outlet is not enough.

You must turn off the main breaker to avoid electrocution and other electrical accidents.

Even when the power is off, the terminals and wires on the main breaker sometimes carry current.

So, it is better not to touch them unless you need them.

You can check the voltage with the voltage tester to confirm that there is no power left in the circuit or the outlet.

Step 2: Remove and disconnect the outlet breaker and wires

Find the particular terminal with a 120V outlet and confirm that you want to convert it to 240V.

Now, loosen the outlet using screwdrivers. Keep the screws and nuts safely aside, as you will need them once the work is done.

Remove the wires attached to the terminal.

Pop the breaker from the panel and keep it aside.

Find the neutral terminal by tracking the path of the white wire connection, and loosen the screw.

Pull the wire out from the bus bar, and color the last few inches with a black marker. It will help you identify the wire while converting the outlet from 120V to 240V.

Step 3: Install the double-pole circuit breaker

Q230 30-Amp Double Pole Type QP Circuit Breaker

Hook two tabs at the back of the 120V double-pole breaker to the lock bar in the breaker panel.

Press the tabs properly and switch the new breaker off immediately.

Find the two terminal screws on the new circuit breaker to loosen them.

Slide the wire connected to the old breaker into one of the terminals and tighten it well.

You must perform this step carefully to transfer the 120V outlet to 240V properly.

Step 4: Install the 240V outlet

Slide the prongs of the neon voltage tester inside the existing socket to check it does not have any current.

If the lamp on the tester does not light up, you can proceed further with the leftover work.

Loosen and remove the screw that holds the 120V outlet cover in its place, and pop it out.

Remove the screws holding the receptacle and bring them out of the electrical box.

Loosen the screws from the terminals and remove the white, black, and ground wires from the receptacle.

Find the green ground wire from the new outlet, and wrap the end in a U-shaped clockwise direction around the screw. Tighten it firmly.

If you have reached this step correctly, you have converted your 120V outlet to 240V. 

Step 5: Check the device

The last step is confirmation.

Once you have covered everything, turn on the circuit and the main breaker.

Slide the prong on the voltage tester to the new socket and check whether it is working.

If the light is on in the tester, then your outlet is working properly.

The lamps will also lighten up to indicate the higher rating.

Make that the new breaker only covers the converted 240V outlet. Otherwise, too much coverage will cause electrical issues and accidents.

Since everything is done safely, you can power your appliances that need 240V.

Arrange all the wires together and push them inside the circuit and outlets. Cover them with the respective cover plates and screws.


Following this procedure is a good way to convert an outlet from 120V to 240V for appliances like air conditioners, provided the outlet is the only outlet controlled by the breaker.

Replace the breaker with another circuit breaker that has the same current rating.

You will find the current rating listed on the breaker’s switch handle. It will ensure that the wires are protected from overloading.


You must verify the circuit breaker controls for the outlet you wish to convert.

The circuit breaker should not control any other outlet or light fixture.

Always turn off the power to work on your house’s electrical system.

How to wire a 240V electrical outlet?

Wiring a 240V outlet for conversion will let you run multiple heavy-duty appliances and garage tools.

A 240V outlet will carry double the current that a 120V can carry.

Working with electricity can be dangerous. So, you must know the proper steps to wire a 240V.

Things required:

  • 240V outlet
  • Screwdriver
  • Voltage line tester
  • Wire stripper or cutter


  • Turn off the outlet power at the main breaker. Use a voltage line tester to make sure there is no power running.
  • Remove the cover plate screw and the plate over the outlet with screwdrivers.
  • Remove the screws holding the outlet and pull the outlet about 3-5 inches.
  • Unscrew the screws that hold the wires at the back to loosen and remove them. Keep the outlet aside.
  • Cut the bad ends of the wires and rip out 1-inch wire insulation.
  • To connect the wires, you must follow proper methods according to the number of wires.
  • For 4 wires, connect the ground wire to the screw at the bottom of the plug (green), the white wire to the center or silver screw, and the remaining black and red to the top 2 screws, which are golden or brass.
  • For 3 wires, connect the ground wire at the bottom of the outlet and the white and red/black wires to the top 2 screws on the outlet. Tighten the screws properly.
  • Mount the outlet back to the electrical box and cover them back.
  • Turn on the power at the breaker in the main circuit. Use a tester to confirm that power is getting into the outlet.


Do not ever perform any electrical work without turning off the main power. It can be deadly.

Follow all the electrical codes in your area.

Follow the NEC (National Electric Code) rules.

If you have local codes that differ from the NEC codes, prioritize the local codes.

Why is it important to have 240V outlets?

240V outlets have a lot of importance for some household appliances.

Though most US countries lead their life with 120V outlets, sometimes 240V outlets are needed for some specific appliances that need higher voltages for power transmission.

The most common appliances that use 240V outlets are refrigerators, ovens, and dishwashers.

The utility room contains some washers and dryers that use 240V outlets.

Other than these, some other larger appliances use more energy than the average level and, thus, need high-voltage outlets.

Some tools like welders and air compressors also require larger outlets with 240V.

Sometimes, these tools will also work well in 120V outlets. Ovens will give low heat in 120V outlets, but they will still produce heat which might be good for some dishes.

But, some of them will need 240V only, and thus, you must plug them into a 240V outlet for smooth functioning.

How long does it take to install a 240V outlet?

If you wish to add an outlet to the existing wiring system, then installing the new outlet will take a few hours.

But, it will take a little longer if the existing wiring does not support 240V outlets. So, you have to replace the wiring to make it support 240V.

It will take from morning to afternoon or a few days to snake the wiring through the wall and then hook it up to the new circuit on the electrical panel.

If the work is a little complicated, it may take one week or more. Upgrading the electrical panel might be necessary, but that will be a completely separate project.

The electrician will have to open the walls to move the wires around and finish installing.

Generally, the time range to install a 240V outlet or convert a 120V to 240V depends on the work challenge. It can either take a few hours or a few weeks.

Is installation of 240V outlets very hard?

It is very easy to install a 240V outlet as it takes a few hours. The difficulty arises when the wire does not support 240V.

You might have to add a new circuit to the electrical panel to run the wires. This method is also easy, but it takes time.

Besides, you must hire an electrician to do this job because things will go over your head if you are naive about it.

What is the cost of installing 240V outlets?

The main problem in installing or converting the 240V outlet is you need new wires to run if the present wire does not support 240 volts.

You will need a new circuit in the electrical panel to run the wires.

Most US homes are designed with 120V, and only the utility room and kitchen have 240V as it contains larger appliances.

120V circuits will cost around $150 to $250. To convert it to 240V, you must add a 240V circuit, which costs $300 to $800.

But, depending on the work challenge, you might have to pay more than $300 to $800.

Additional cost

Converting the outlet from 120V to 240V will cost around $300 to $800.

Snaking the new wires will cost around $500 to $1,300 per project or $25 per foot.

If you have to upgrade new wiring, that will cost $2,000.

Sometimes, the electrician might have to rip open the walls. In that case, you will have to pay thousands of dollars.

The cost of an electrician to convert the outlet from 120V to 240V can cost around $30 to $50.

Final thoughts

There is no problem converting an outlet from 120V to 240V, provided only one outlet is in the circuit.

For converting an outlet from 120V to 240V, you need to change the breaker to a 2-pole 240V breaker. All your 120V wires will get rated at 240V.

Most of the US houses will have 120V. People use multiple appliances at this voltage, but some larger appliances, like ovens, dryers, washers, etc., need a higher voltage.

That is why it is important to have a few 240V outlets.

You can run some larger appliances like ovens on 120V outlets, but they will produce heat lower than the average rate.

The cost of 240V outlets is very cheap, around $15. Installation of 240V outlets will cost $300, and converting a 120V outlet to 240V will cost around $300 to $800.


What is the difference between 120V and 240V?

A normal 120V outlet will have a 120V wire, a neutral wire, and a ground wire. A 240V outlet will have two 120V wires and one neutral wire.

A 240V can transmit power more efficiently than 120V.

How can I get 240V from a 120V outlet?

You can use a transformer to convert 240V to 120V.

Another way is by using a powerstrip. Powerstrips can convert 240V to 12V.

Another way is to use a Converter box to convert voltages between 240V and 12V.

Are 220V and 240V the same voltage?

220, 230, and 240 fall in the same voltage categories. However, 208V belongs to a different voltage category.

In northern America, utility companies deliver split-phase 240VAC for residential uses.

What cable is good for 240V?

You can run a cable from a 240V circuit to the breaker box. Use a 4-strand cable gauge to operate the power rating of the breaker.

A 15 amp breaker will have 14 gauge wires, and a 20 amp breaker will need 12 gauge wires.

Reference: University of FloridaElectrical systems differIEC World Plugs, ResearchGate, Electrical Injuries.

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Arthur Smith

Howdy! I am Arthur Smith, an electrical engineer who is extremely passionate about electronics. I have lived in different parts of the US and currently reside in Wisconsin. I am one of those rare children who knew what he wanted to study and do in life right from the start. I was a curious child who wanted to know how switches work and how the AC works, and I would always observe my dad whenever he would handle the wires and fix things around the house. I currently work as an electrical engineer at a reputed company and write for this blog. And I read loads of books or play video games in my free time.

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