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Suppose I have a house in Europe. The house is of course wired with 230V, which means it won't work directly with US plugs.

If I acquired US outlets, how would I convert a single European 230V circuit to the US standard 120V as easy as possible?

I don't want external devices/transformers after the outlet. I want actual US 120V outlets that power US devices.

Let's assume 230V/50Hz to standard 120V/60Hz.

I'm looking to install permanent US outlets into a European house. I won't be converting the whole house, just a few outlets.

I know this isn't just plug and play. I want to install the wiring to make it just like the US.

Again I'm talking about house wiring. Rewiring part of the house to use 120V. Not "adding" adapters, UPS backups, transformers, etc after the electrical outlet. No. Make part of the actual house wiring native 120V.

Native US-style 120V outlet wiring.

How can I make it so a US wall outlet can be installed in the wall and US devices can be plugged in normally with US plugs (no device adapters)?

Local Regulations are not important, I am asking for the technical aspect.

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  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – Voltage Spike
    Apr 21, 2022 at 22:08
  • \$\begingroup\$ You should only accept the answer that best answers your question, not the first one to answer. You can change your accepted at anytime just fyi. \$\endgroup\$
    – Passerby
    Apr 21, 2022 at 23:21
  • \$\begingroup\$ I know. I think they answered third. Anyway I chose that one because it actually answered the actual question (how to actually do it) and taught me the things that I needed to know that answered the question in full, even including additional alternatives. The other answers were also great but not as comprehensive. I think the one that said "Convince your local power company" was the first answer, and I didn't accept that answer as best. I gave your answer which was also excellent @passerby an upvote as well. \$\endgroup\$
    – electrical
    Apr 21, 2022 at 23:31

8 Answers 8

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Without a transformer, you can't.

Houses in Europe get either single phase or three phase 230VAC.

Houses in the US get single phase 240V that is split into two phases of 120VAC by the transformer outside the house.

The only way to get 120VAC from a European outlet is to use a transformer.

If you want to install a bunch of 120VAC outlets in your house you'll have to install a large transformer then run wires to all of your 120VAC outlets.

That probably won't meet the standards for electrical wiring in European countries.

Don't bother. Use European 230VAC appliances connected to normal 230VAC outlets.


A transformer won't do anything for the line frequency. With a transformer you'd get 120VAC at 50Hz.

You'd need something to convert the frequency and the voltage.

That'd be a UPS kind of setup that takes in 230VAC at 50Hz and puts out 120VAC at 60Hz - I don't think anybody makes such a beast.

You could use a transformer to get 120VAC, then use a variable frequency drive to convert the 50Hz to 60 Hz. Again, it would be odd to find one that takes in 120VAC at 50Hz.


You could import a photovoltaic system made for the US, one with a local battery storage.

You'd have to have one made to not connect to the power grid. Normal systems are made to synchronize with the grid - that won't work for a 60Hz PV system anc a 50Hz grid.


Just get 230VAC appliances like everybody else in Europe and get on with your life.

I can't think of a single advantage to using 120VAC equipment that would make it worth the hassle.

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  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – Voltage Spike
    Apr 22, 2022 at 16:03
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If we ignore regulations, the technical aspect is easy.

You already know you need a transformer to get 120 from 230 single phase used in Europe. Many devices can deal with 50 Hz instead of 60Hz so a converter is not needed, but you can use one if required.

There are off the shelf systems that do this. A commercial UPS can do it. I use a tripplite 6000 VA system that has an inverter that can take 230 and put out 120, while changing the frequency from 50 to 60 or 60 to 50. Uses a standard L6-30 30 amp input connection and L6-20 outputs, made for computer server rack needs.

Plug that into an appropriately sized 230V circuit, wire the output to a dedicated subpanel and branch off circuits for outlets using US wiring standards from there. Bonus you have a UPS for any blackouts. With the 6000 VA one you can get 3 15 Amp circuits, which would put it at a rule of thumb 24 outlets for general use. YMMV.

Obviously that may be overkill, and local electrical regulations would not approve. Have you considered just getting some large capacity power distribution modules screwed into a workbench? You would still need the 230V 30 Amp connection, and the rest is Plug and play instead of in wall wiring.

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  • \$\begingroup\$ Fantastic answer, and another real-world use case \$\endgroup\$
    – electrical
    Apr 21, 2022 at 19:52
  • \$\begingroup\$ Also really liked your solution about a smaller transformer, which actually might be the most efficient solution. Power distribution modules. What kind? Where to get them? I could install it somewhere and then run a wire through a wall to an outlet where I need it. Or just use under the desk or workbench. \$\endgroup\$
    – electrical
    Apr 21, 2022 at 19:54
  • \$\begingroup\$ A PDM or PDU @electricaladdict is a fancy name for power strip. I'm suggesting one like images.thdstatic.com/productImages/… in addition to the transformer/converter. \$\endgroup\$
    – Passerby
    Apr 21, 2022 at 21:58
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    \$\begingroup\$ Even though this is an excellent answer, the reason I chose the other one was because it gave me background on things like how transformer really is needed, and how even after the transformer, it would transform 230/50hz to 120/50hz, and still needs to change the frequency. I liked your answer, but it was not as comprehensive, even though I didn't like that the other answer said things in the negative (I don't like naysayers). He told me how houses in the US get their power also from 230v and transform it outside the house. Something I really needed to know meaning it's possible to do the same \$\endgroup\$
    – electrical
    Apr 21, 2022 at 23:40
  • \$\begingroup\$ So there were several key points in the accepted answer that enlightened me to a high degree and answered the question, so that's why I accepted that one, even though yours is also fantastic. I hope you get more upvotes too. The accepted answer gave me key background that told me not just how but also why, which is critical for me knowing the technical info is correct. \$\endgroup\$
    – electrical
    Apr 21, 2022 at 23:42
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Note: this is https://electronics.stackexchange.com, not https://diy.stackexchange.com so this answer only covers the electrical side of the question, not the building code side. It might be illegal to have the wrong kind of sockets permanently installed, or there might be special rules for wiring them. Consult a licensed electrician.


About the voltage: There is no "native house wiring voltage". Actually, it'll be the same wiring (ignoring regional differences like colour codes, types of cable, etc). The main difference between 120V wiring and 240V wiring is that 120V wiring is connected to 120V power and 240V wiring is connected to 240V power.

In the USA they have a mixed 120V/240V system which is why you can wire up a 240V outlet or a 120V outlet. However, in Europe there is only 240V (or 230V - whatever, close enough). To get 120V you need to transform it somehow - you can't do it just by shuffling wires around. Even in the USA, they use transformers to make the two different voltage. It's just that the transformer is on a power pole, not in your house.

That doesn't mean you won't be able to plug US appliances straight into the wall, though. It just means the transformer has to be somewhere else. For example, you could have a big one in your basement (not building code advice) or a small one in each socket (may cause problems with cooling, not heat dissipation advice).

Either way, if you can get some 120V power and wire it to a US socket, you can simply do that. It's not like Europe has a 120V repellant forcefield.


About the frequency: frequency can't be converted by transformers - it requires an electronic converter or a motor/generator set.


About the sockets: You would probably have to order US sockets from the US, and there's a chance customs may ask what you are doing with them as they won't be approved for use in Europe by European standards. Since it's a free country (or conglomeration of countries), I would expect you'd be allowed to somehow import them for your own usage, but maybe there will be paperwork to declare you're not a shady electrician installing unapproved sockets in other people's houses.


About legal liability: your home insurance company might not like you installing Weird Stuff as they can't trust it won't catch fire. If you live in an apartment building the management might not like you installing Weird Stuff as they can't trust it won't catch fire. Again, consult a licensed electrician.

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Convince your local power company in Europe to generate 120V 60Hz and run a line to your house. Other than that, you're stuck with installing a transformer in your house if you're OK with 120V 50Hz, or a PFC/Inverter if you truly need 60Hz. You could put the transformer or inverter in your basement and wire the output to outlets in the house, but beware the local electrical codes.

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    \$\begingroup\$ Saying to convince a power company would cost millions, that's not an answer. You should delete that and elaborate on the second part of your answer. \$\endgroup\$
    – electrical
    Apr 21, 2022 at 17:04
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    \$\begingroup\$ The first part of your answer though makes me realize that if I generate my own power using my own equipment like solar or hydroelectric, I could set it up as 120v, and could also convert it more easily into 230v as well. \$\endgroup\$
    – electrical
    Apr 21, 2022 at 17:08
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    \$\begingroup\$ @gameaddict I disagree, it's an impractical answer for sure, but it's designed to point out the impracticality of what the OP wants to do given his/her original constraints. \$\endgroup\$
    – John D
    Apr 21, 2022 at 17:18
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    \$\begingroup\$ @gameaddict It points out the absurdity of asking to change voltage without using any kind of voltage-changing equipment. You say you want a different voltage. Then you say you don't want to use all the kinds of things that can change voltage. Nuh-uh, won't work. \$\endgroup\$ Apr 21, 2022 at 17:19
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    \$\begingroup\$ @electricaladdict It's maybe worth pointing out that outlets are not special in any way whatsoever. They are just connectors that happen to screw into walls. The back side of an outlet can be wired to 240V, 120V, 12V, AC, DC, cable TV signal, ham radio, electrocardiogram, whatever you like. For an "art project" I have wired a microcontroller to an outlet. So there is nothing in the laws of physics that stops you from wiring one to the output side of a transformer. \$\endgroup\$ Apr 22, 2022 at 9:24
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To convert voltage from 230 to 120 V as well as frequency from 50 to 60 Hz you need something like the SFC MM 3 kVA see http://www.cysco.de/download/CYSCO-SFC-Lieferuebersicht.pdf

Of course there are some other manufacturers, but I don't think you need models for 5 to 500 kVA like these https://www.piller.com/de-DE/199/statische-50-60hz-frequenzumformer

But I would not be surprised when a 3 kVA unit without any load active would consume about 30 to 60 W.

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It seems quite an adventure you are putting yourself into. The big question is why exactly do you want actual US 120V/60 Hz outlets in Europe.

  • If you intend to just use devices with switching power supplies (laptops, phone chargers, TVs,...) it is probably not worth the hassle as these devices nowadays are flexible enough to deal with pretty much every voltage/frequency you throw at them.

But I assume you know that. So lets assume you have some other kind of gear (probably older/professional/industry... stuff) that really expects a decent us outlet. In that case

  • a 'simple' transformer won't cut it for you as it would only convert the voltage while keeping the line freq at 50 Hz.
  • you would need a 230V to dc converter and a dc to 120V/60 Hz inverter (the last part is pretty common nowadays in pv installations)
  • there might be some manufacturer who offers something like that but I haven't heard of any. And even if there is one, it will probably cost you a 5-digit figure as it probably is not a mass market device already designed, tested and certified. You will probably need to rig something up yourself.
  • this leads to the question how much current/power you need. (You mention a couple of outlets. With typical 120V/15A outlets we are looking at almost 2 kW per outlet. So you need a rectifier/inverter combo capable of 6-10 kW... quite a bit of juice.) Special, us-type breakers, at least one breaker panel to mount them, us-style RCDs, and an appropriate gauge cables come on top.
  • you will probably need to install all that stuff yourself as probably no professional electrician will be able or willing to install that for you.
  • and kiss goodby to any kind of fire insurance for that building as this kind of setup is nowhere close to any valid electrical code.

Nevertheless, from a technical perspective, doing something like that is possible and honestly not really complicated. So if you decide to go that route please let us know how it turns out.

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    \$\begingroup\$ You don't have to tinker the device from a "230V to dc converter and a dc to 120V/60 Hz inverter". There are several industrial products available that will be installed by a professional electrician, that meet the regulations and that are accepted by fire insurances. \$\endgroup\$
    – Uwe
    Apr 22, 2022 at 15:07
  • \$\begingroup\$ That's good, since I don't want "insurance". anyway. I just don't do stupid things that burn the house down. I haven't burned a house down yet. \$\endgroup\$
    – electrical
    Feb 21 at 2:57
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I wont exactly answer the question here, but I will warn you (as someone who has had property in Europe) that the European electrical regulations are very strict in many countries (UK / France / Germany / Switzerland especially). In some of the European countries it is also a requirement to get your home's electrical installation inspected every 'X' years, or when the home changes hands. If the installation fails an inspection (Google 'EICR inspection' in the case of UK), the electrician could theoretically disconnect your entire home from the grid until those issues are resolved!

The other issue is property and contents insurance. If you have non-standard wiring for the country regulations and specifications, you'll be left un-insured regardless of the policy inclusions/exclusions (and therefore could lose the entire value of your investment and home!)

I would suggest the simpler option of just buying European standard appliances which come with all the appropriate regulations, and equipment which comes with a transformer (laptops, cameras, and other low voltage items) often allows 110v-240v voltage input anyway. The rest just bite the bullet!

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  • \$\begingroup\$ In response to the last paragraph: If it outputs DC, it's not a transformer. There's usually a transformer somewhere inside it, but the whole thing is a power supply or an AC-DC converter, not a transformer. \$\endgroup\$
    – Hearth
    Apr 22, 2022 at 17:02
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It is very very simple - and I have done it. And I am even a native European :-)

  1. I bought an American record player - and the internal motor required 60 hz (and 120v) to run correctly.
  2. Just for fun, I decided to make an “American outlet” with the correct voltage (120v) and correct frequency (60hz)
  3. On this homepage, I bought a 2kw frequency converter. 2kw is the normal max capacity for a single outlet. https://www.gohz.com/2kva-frequency-converter
  4. I built the frequency converter into a closet behind the outlet.
  5. If needed, more outlets can be connected, and the only thing missing will be the American flag (Stars and stripes) on the wall, to make the illusion about being in America complete :-)
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  • \$\begingroup\$ $2200 is a bit crazy. Sounds more like a clever sales pitch. I could replace all my American electronics for less than the cost of the device. And most American electronics only need an adapter that costs 50 cents because they're compatible with 110-240 50/60hz \$\endgroup\$
    – electrical
    Feb 21 at 2:49

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