https://electronics.stackexchange.com/questions/115200/why-does-the-usa-use-110v-and-uk-use-230-240v Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Visit Stack Exchange [ ] Loading... 1. + Tour Start here for a quick overview of the site + Help Center Detailed answers to any questions you might have + Meta Discuss the workings and policies of this site + About Us Learn more about Stack Overflow the company, and our products. 2. 3. current community + Electrical Engineering help chat + Electrical Engineering Meta your communities Sign up or log in to customize your list. more stack exchange communities company blog 4. 5. Log in 6. Sign up Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It only takes a minute to sign up. Sign up to join this community [ano] Anybody can ask a question [ano] Anybody can answer [an] The best answers are voted up and rise to the top Electrical Engineering 1. Home 2. 1. Public 2. Questions 3. Tags 4. Users 5. Unanswered 3. Teams Stack Overflow for Teams - Start collaborating and sharing organizational knowledge. [teams-illo-free-si] Create a free Team Why Teams? 4. Teams 5. Create free Team Teams Q&A for work Connect and share knowledge within a single location that is structured and easy to search. Learn more about Teams Why does the USA use 110V and UK use 230-240V? Ask Question Asked 9 years, 2 months ago Modified 4 years, 6 months ago Viewed 159k times 30 \$\begingroup\$ Why does the USA use 110V and UK use 230-240V? What are the advantages? Explain me with calculation. Why do they use different frequencies like 50Hz, 60Hz? What is the reason? * power-supply * power * transformer * power-electronics * transmission-line Share Cite Follow edited Jun 14, 2014 at 7:58 starblue's user avatar starblue 6,46222 gold badges2121 silver badges3535 bronze badges asked Jun 13, 2014 at 6:57 user43153's user avatar user43153user43153 42122 gold badges55 silver badges66 bronze badges \$\endgroup\$ 6 * 11 \$\begingroup\$ USA uses 230-240 VAC, too. The only difference is that we ground it in the center, creating "split" phases, reducing the peak voltage relative to ground and making it easier to interface low-power loads. But high-power loads (stoves, water heaters, clothes dryers, etc.) operate across the full voltage, reducing the current required. \$\endgroup\$ - Dave Tweed Jun 13, 2014 at 12:06 * \$\begingroup\$ @Raggles Car hits pole and there may be 7.2kV wire on the street. Tree falls on line and here we go - little disaster. Thats kind of dumb for me. Here where I live we have 15 or 30kV lines too, but in my town - there are just few lines like this, they are far from roads, trees etc. \$\endgroup\$ - Kamil Jun 13, 2014 at 18:44 * \$\begingroup\$ Can mention that not only the UK, but most (all?) countries in Europe uses 220-240V/50-60Hz. \$\endgroup\$ - Baard Kopperud Jun 14, 2014 at 10:52 * 5 \$\begingroup\$ 230 V is used in whole Europe, but only 50 Hz and not 60 Hz. \$\endgroup\$ - Uwe Mar 28, 2017 at 20:24 * \$\begingroup\$ @DaveTweed Interesting. My kitchen hobs use two 220V phases (I guess that means 440V?). Does that mean that there's no equivalent in the US market? \$\endgroup\$ - WhyNotHugo 6 hours ago | Show 1 more comment 7 Answers 7 Sorted by: Reset to default [Highest score (default) ] 21 \$\begingroup\$ You should not be surprised that they use different voltages and frequencies, you should be surprised that there are only two big voltage/frequency standards. When electricity was first introduced each producer provided a different voltage and frequency (or even DC instead of AC). Gradually producers merged, governments set standards, and market pressure demanded that appliances could be used everywhere. This lead to the current situation, where the pressure for a world standard is counterbalanced by the invested interests. For the same amount of energy 110V requires more current, hence thicker wires. 230V requires better isolation. In some rare situations 220V might be more dangerous to touch. I don't think 50 or 60 Hz makes any significant difference. (An iron core for a transformer might be a little smaller at 60 Hz. But iron cores are soooo last century...) Share Cite Follow answered Jun 13, 2014 at 7:14 Wouter van Ooijen's user avatar Wouter van OoijenWouter van Ooijen 48.4k11 gold badge6363 silver badges136136 bronze badges \$\endgroup\$ 10 * 6 \$\begingroup\$ About safety I once did a little math and it seemed that 110V versus 230V is the difference between life and death. \$\endgroup\$ - Vladimir Cravero Jun 13, 2014 at 7:31 * 17 \$\begingroup\$ In some circumstances it might. In other circumstances it might mean the difference between death and death. \$\endgroup\$ - Wouter van Ooijen Jun 13, 2014 at 7:33 * 2 \$\begingroup\$ Yeah of course if you bite a 50V wire while your feet are deep in the water you have no chance, but if I recall it right making some "real life, common" assumptions lead to what I said. \$\endgroup\$ - Vladimir Cravero Jun 13, 2014 at 7:35 * 3 \$\begingroup\$ 50Hz is just above the limit of when the eye will detect flicker, an important concideration with old-style light-bulbs and such. Can mention that for a while in some industiral towns (at least in Norway), frequence was decided by what was best for the industry - eg. melting aluminium. So some places they used 25Hz, and you could see the lights flicker - and the required size of the transformers... (lower freq., more iron). \$\endgroup\$ - Baard Kopperud Jun 14, 2014 at 10:50 * 4 \$\begingroup\$ @BaardKopperud - "an important concideration with old-style light-bulbs and such" - Exactly backwards, unless you consider fluorescents "old-style". A more reasonable view of "old-style" (at least as far as line frequency selection is concerned) is incandescents, and those puppies have enough thermal inertia in the filaments that there is no perceptable flicker at 50 Hz, or even at 30 Hz. \$\endgroup\$ - WhatRoughBeast Feb 19, 2019 at 23:35 | Show 5 more comments 7 \$\begingroup\$ The same reason we still pave roads that go around buildings that were knocked down half a century ago. Historically someone, or some group, picked a number in each country, others followed suit, and it became "a standard". Now we are stuck with them. Each has it's advantages and disadvantages. You can argue them forever. Share Cite Follow answered Mar 28, 2017 at 18:36 Trevor_G's user avatar Trevor_GTrevor_G 46.4k88 gold badges6868 silver badges151151 bronze badges \$\endgroup\$ 1 * \$\begingroup\$ There is an even more wonderful example of how such things stick and then it's too expensive to change. Eastern Japan uses a 50 Hz grid (historically built by German companies), while western Japan uses 60 Hz (American). There's no way to consolidate them now. npr.org/2011/03/24/134828205/... \$\endgroup\ $ - 9000 4 hours ago Add a comment | 6 \$\begingroup\$ It's hard to be definitive. But before AC power distribution was widely adopted, there was a bitter battle in the United States between Edison and Westinghouse about DC versus AC power distribution . Edison's DC system used +110V, 0V and -110V . There was a campaign by Edison to portray AC as dangerous, even going so far as to introduce an electric chair powered by AC electricity as an execution device, thereby demonstrating the "danger of AC". Once AC was widely accepted as being superior to DC for power distribution, 110V became the standard for AC distribution presumably because it used the "safer" Voltage level of the DC system. After metal filament lamps became feasible, 220V became common in Europe because of the lower distribution costs. As for 50Hz versus 60Hz.. well that's just the Metric system. Share Cite Follow edited Jun 13, 2014 at 11:16 answered Jun 13, 2014 at 9:19 akellyirl's user avatar akellyirlakellyirl 4,11711 gold badge1616 silver badges3030 bronze badges \$\endgroup\$ 7 * 2 \$\begingroup\$ 50 vs. 60Hz is actually not a metric system issue, but a choice to be able to easily multiply/divide the mains frequency into or out of clocks. 60Hz divides much easier mechanically as it has many divisors. \$\endgroup\$ - user36129 Jun 13, 2014 at 10:06 * 1 \$\begingroup\$ Could be one reason but quoting from school-for-champions.com/science/... "With the backing of the Westinghouse Company, Tesla's AC system became the standard in the United States. Meanwhile, the German company AEG started generating electricity and became a virtual monopoly in Europe. They decided to use 50Hz instead of 60Hz to better fit their metric standards" \$\endgroup\$ - akellyirl Jun 13, 2014 at 11:16 * 1 \$\begingroup\$ Actually, the original Edison incandescent lamps were nominally 100 volts. 110 was chosen as the distribution voltage to allow for line drops (a major problem with early DC power systems such as Edison built.) \$\endgroup\$ - WhatRoughBeast Jun 13, 2014 at 12:44 * \$\begingroup\$ Amazing how the metric system affects every little thing, from the mains frequency to the name of hamburgers. \$\endgroup\$ - dim May 26, 2016 at 9:28 * 1 \$\begingroup\$ Side note: "AC was [...] superior to DC for power distribution" at the time, when power stations served smaller areas, copper was cheap, and you didn't have high-power electronics that could convert DC to AC and back whenever you needed to step down the voltage. (An AC transformer can sit in a cabin or on a utility pole for years with little to no maintenance; a DC motor-generator cannot.) These days, HVDC lines are in fact deployed in some places. \$\endgroup\$ - Alex Shpilkin 12 hours ago | Show 2 more comments 5 \$\begingroup\$ The 110V issue is simply that once Tesla and Westinghouse proved long distance AC transmission feasible, the #1 issue driving the proliferation of electrification was lighting in houses, replacing the gas and oil lighting that was a major fire hazard of the day. Edison's lamps were 100V, but a lamp does not care if it gets AC or DC. So our AC distribution system, AT THE RESIDENTIAL LEVEL, was designed to take advantage of the existing installed base and inventory availability of Edison's lamps. Then as personal appliances began proliferating, they were designed to take advantage of the 110VAC lighting circuits already used in houses and the concept cemented itself into our culture to where there was no going back. The 50/60Hz issue is different and is not "metric" at all (what's metric about the number 50?). Despite Westinghouse/Tesla having championed it, AC only really took off here once Edison gave in to the inevitability. Edison, despite having investing in AEG as Europe began electrifying, was reluctant to allow a system in which Europeans could enter our market by selling electrical products here. So after also experimenting with different frequencies (40Hz was the first major industrial installation, at the Folsom Power House in California), Edison and Steinmetz settled on 60Hz, partly because of the flicker issue, then also because it would make European equipment incompatible. He wanted it all to himself... which is the same motivation behind his initial push to discredit AC distribution in the first place. He wanted DC because he owned the US patent rights to his DC dynamo (even though he actually bought his first one, for proof of concept, from Werner von Siemens. Yes, THAT Siemens... Siemens had not patented it in the US). So if DC had won, we would have had Edison DC dynamos every 5 miles or so. Only the rich would be able to afford it, and they would all be paying Edison for the privilege. Tesla's egalitarianism ruined his vision. Share Cite Follow answered Mar 28, 2017 at 18:25 JRaef's user avatar JRaefJRaef 3,5511111 silver badges1212 bronze badges \$\endgroup\$ Add a comment | 3 \$\begingroup\$ This was extensively covered in The Simpsons: You know, Europe's no place for a six-year-old. He can handle 110 volt, but 220 would kill him. Jokes aside, once you pick a value and produce a substantial amount of compatible devices, the price of switching to a different value becomes prohibitively high. Share Cite Follow answered Mar 29, 2017 at 7:41 Dmitry Grigoryev's user avatar Dmitry GrigoryevDmitry Grigoryev 25.6k55 gold badges4545 silver badges106106 bronze badges \$\endgroup\$ Add a comment | 2 \$\begingroup\$ We learnt that it was about resources. Europe had abundant iron and was short of copper, hence 50Hz. Whereas (mistakenly) America and particularly Pennsylvania, had a surplus of copper, hence 60Hz. 110v, 60Hz has 4 times distribution loss compared with 220V (power loss = I squared R) That is why American wire is so much thicker and the overhead (not underground) distribution puts on such a spectacular display when a pole mounted transformer goes up. Also, lights flicker at twice the AC frequency, one flash on the positive half cycle and one flash on the negative half cycle, not at the supply frequency Share Cite Follow answered Apr 3, 2018 at 9:40 Max Townshend's user avatar Max TownshendMax Townshend 2111 bronze badge \$\endgroup\$ 3 * 1 \$\begingroup\$ I understand the correlation between current and losses. But the link between raw material resources and frequency choice needs more explanation. \$\endgroup\$ - dim Apr 3, 2018 at 11:53 * \$\begingroup\$ What does it mean to mistakenly have a surplus of copper? Do you mean that it was mistakenly believed that there was a surplus of copper? \$\endgroup\$ - LSpice 12 hours ago * \$\begingroup\$ Whatever voltage the home user needs, 110 or 220, shouldn't really impact the design of transmission lines beyond what actually connects the final transformer to the consumer. \$\ endgroup\$ - Nick T 7 hours ago Add a comment | 2 \$\begingroup\$ In the UK wiring was available nationwide in the late 1950's. The rest of europe followed shortly after the US. Because it took the UK a bit of time to catch up, they had time to learn an important thing about the previous experience with household electricity - wiring houses was expensive! They had to use a lot of wire and by doubling the voltage they reduced the current to half thus reducing the wire gauge needed. The AC freq. is a bit better known story... Up until 1890 there was no standard for the mains freq. (obviously) AEG who had a monopoly on electricity production in Europe set the standard at 40Hz, however a bit later on they had noticed lamps flicker at that freq. so they increased it to 50Hz which was fine. Westinghouse learned about this becoming a standard but they figured the lights still flicker a bit so they increased the freq. to 60Hz. In the following years they started wiring the entire US and motors and other devices were designed for that freq. so it was not easy to change it any longer. Share Cite Follow edited Feb 20, 2019 at 2:41 Dave Tweed's user avatar Dave Tweed 168k1717 gold badges228228 silver badges393393 bronze badges answered Jun 14, 2014 at 9:27 user34920's user avatar user34920user34920 1,87222 gold badges2222 silver badges4444 bronze badges \$\endgroup\$ 2 * \$\begingroup\$ This is all pretty vague and unsupported. I've read that two-thirds of UK rural dwellings were connected by 1938 . Some of it doesn't even make sense. For example, if the rest of Europe 'followed shortly after the US' why did they go for 220V? \$\endgroup\$ - user207421 Jun 14, 2014 at 10:39 * \$\begingroup\$ @user207421 Can't say anything about Western Europe, but the Russian Empire originally used 110V in the 1880s; the Soviet Union variously used 120 or 127V ( = 220V / [?]3) and ultimately switched to 220V ( = 380V / [?]3) over several decades starting in the 1930s (presumably for efficiency reasons). That was further tweaked to 230V ( = 400V / [?]3) in Russia in the 2000s, although given line loss in the apartment wiring in practice you get anywhere from 225V normally to 215V on a particularly bad day. \$\endgroup\$ - Alex Shpilkin 11 hours ago Add a comment | Highly active question. Earn 10 reputation (not counting the association bonus) in order to answer this question. The reputation requirement helps protect this question from spam and non-answer activity. Not the answer you're looking for? Browse other questions tagged * power-supply * power * transformer * power-electronics * transmission-line or ask your own question. * The Overflow Blog * Fighting comment spam at Facebook scale (Ep. 602) * What it's like being a professional workplace bestie (Ep. 603) * Featured on Meta * Moderation strike: Results of negotiations * Our Design Vision for Stack Overflow and the Stack Exchange network Linked 0 Why is the domestic power supply almost universally supplied at 230V? 0 using 50hz frequency in ac current Related 2 Does using 220V-110V transformer matter? 1 230 and 240 transformer leads 4 Why 220V and 110V? 3 Given the current and voltage of a consumer electronic device, how to calculate its power draw? 2 Why are EI-cores (shell-type) most common for power transformers? 0 Step down transformer for a 1 HP Kitchenaid mixer 5 Relation between transformer core material and application frequency 1 Converting a DeWalt charger from 110V to 220V, rational of component selection from the guide Hot Network Questions * Indispensable, Essential, "Tool of the trade", "Staple item" * How would you say "I can't help but wonder whether..." in Latin? * Why are radio telescopes often built into natural depressions? * What do Americans say instead of "can't be bothered"? * Rotation constraints overwrite inherited scale * Blockchain pruned node still downloading old blocks * Calculate the Distance to a Line Segment * Would it be possible to make a custom zoomable world map (kinda like google maps)? * First appearance of the "four triangles and a square" proof of the Pythagorean Theorem * Should I send an email to African American colleagues given a recent nearby targeted crime? * Is Saturday considered a weekday or weekend, or something else? * Sustainable eating habits as a pilot * What RPM to check timing? * Is tropylium cyclopentadienide possible? * How you get any work done is beyond me? * may(=possibility) vs. can(=possibility) * Coworker hiding and stealing lab material * Exercise asking what a transistor circuit does * Why error An internal server error has occurred Error ID: 1065883952-6153 (1010177878) happens? * Salary hike for Teaching * Small dents on bicycle frame * Is wearing a mask in public a no-no (making one looks weird)? * Was there a German embassy open in 1941 Lisbon? * Is the liquid inside the canned chickpeas meant for consumption? more hot questions Question feed Subscribe to RSS Question feed To subscribe to this RSS feed, copy and paste this URL into your RSS reader. [https://electronics.] * Electrical Engineering * Tour * Help * Chat * Contact * Feedback Company * Stack Overflow * Teams * Advertising * Collectives * Talent * About * Press * Legal * Privacy Policy * Terms of Service * Cookie Settings * Cookie Policy Stack Exchange Network * Technology * Culture & recreation * Life & arts * Science * Professional * Business * API * Data * Blog * Facebook * Twitter * LinkedIn * Instagram Site design / logo (c) 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. rev 2023.8.29.43607 Your privacy By clicking "Accept all cookies", you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Accept all cookies Necessary cookies only Customize settings