28 ms·

Why does the USA use 110V and UK use 230-240V? (2014)

207 points by dilawar 3y ago

SeanLuke 3y ago
There were many factually correct, and even historically interesting responses. But not a single response answered the question.
- antegamisou 3y ago
  Welcome to *.stackexchange.com
- wongarsu 3y ago
  I'm not sure there is a good answer, beyond "the US stuck with Edison's 110V, Europe went with 230V because it's cheaper". Both 110V and 230V are reasonable choices. And of course technically the US primarily uses 230V split between two phases. But Europe mostly uses 3-phase 400V, with each phase delivering 230V (because phases are 120° offset to each other), so then we are just talking about 230V vs 400V, and two vs three phases.
  - oblio 3y ago
    > Both 110V and 230V are reasonable choices. Are they, though? With modern appliances, power requirements are going up and 110V is struggling to keep up. One example would be an induction hob. I know that technically US homes can access 230V but they aren't wired for that, probably 99% are wired just for 110V except for maybe a few special lines.
    - wongarsu 3y ago
      Interestingly enough, European oven/hob combos mostly run on 400V 3-phase power. Same for many tankless water heaters. That's certainly one advantage of 230V per phase. It's probably also one factor in the decision to power things by gas vs electric.
      - rootusrootus 3y ago
        But are they more powerful? AFAIK it's pretty common for a European range to be in the 7000-10000 watt range. That's also normal in the US on single phase 240V. And I can go buy a 36000 watt tankless water heater from Home Depot. I think it's a wash, either system can deliver however much power you need. The reason for gas in the US is because people like it. It's been seen as upscale for decades to have a gas cooktop. It also helps that gas water heaters don't require electricity and work in an outage. Our residential natural gas distribution network is extensive and reliable, and it's pretty straightforward to use the same appliances on propane for people out in the sticks.
        vel0city 3y ago
        Depending on the market it can also be cheaper per BTU to heat with gas than with electricity, at least resistive heating. Heat pumps are starting to challenge that math, but with higher upfront costs and more complexity as tradeoffs.
    - michaelt 3y ago
      > With modern appliances, power requirements are going up Things like lightbulbs and TVs and computers and refrigerators are using less power than ever before. Of course, if people are buying electric cars or replacing gas furnaces with electric heat pumps, then you're right on that side of things.
      - oblio 3y ago
        > Things like lightbulbs and TVs and computers and refrigerators are using less power than ever before. Are they, though? Lightbulbs, sure, we won with LEDs. But TVs, especially the huge, high brightness ones we have nowadays? And with the extra computing needed? Computers, same, I only see power usage going up. I mean PCs, we're not comparing things with mainframes here :-) Refrigerators: are they really more efficient? Now add: heat pump, induction stove, electric oven, more powerful AC, humidifiers/dehumidifiers, etc.
        michaelt 3y ago
        Compared to the age of CRTs, modern TVs are much more power efficient. And compared to the age of the Pentium 4 with its 100W+ TDP, laptops now outsell desktop computers by a long way. (I would agree that things like high-end gaming GPUs are using more power than ever before - but they're also a much smaller % of sales than ever before)
        oblio 3y ago
        > Compared to the age of CRTs, modern TVs are much more power efficient. According to the internet a CRT TV used to use about 100W, while a big LCD TV can use more. Regarding desktops, don't forget that these days we have many more electronic device in a home. Smart speakers, home media devices, consoles, etc, etc. Electronics probably use, in aggregate 5-10x what the old family PC used to use, I'd imagine.
        selectodude 3y ago
        A 32” Sony trinitron would pull down about 200W. An 85” LCD will pull down about 150W.
    - wil421 3y ago
      Laundry, stove, and ovens use 240V outlets (assuming no gas). It’s not very common but I know a few people with wood working tools who have installed 240v outlets. Wood framed houses make it easy to change wiring. To change my gas stove/oven back to 240v induction would be a 15 foot run of romex, a new outlet, and probably an updated circuit breaker. Possible for a DIYer to do.
    - vel0city 3y ago
      Every US home I've lived in had 240V access in the kitchen for appliances like electric ranges. They absolutely are wired for that. Practically nobody's house only has 120V.
      - gibspaulding 3y ago
        It sounds like you've always lived in relatively new/high end houses then. Older houses might have a dedicated 240 plug for the dryer and the stove if they're not natural gass, but for everything else there are plenty of homes full of ungrounded 10 amp 120v circuits.
        vel0city 3y ago
        My current house was built in '82. Is that a new house? That's 41 years old at this point. Its a pretty average single family suburban build for the time, not anything especially fancy even for its day. Loads of houses we looked at in the area were built in the 70s and 60s and often had electric 240V appliances in the kitchen. That's about 60 years old, is that a new? A single car garage 1500sqft 3bdr house in a suburb sound like a high end house? And yeah, my house is full of 120V circuits, but once again the house has 240V at the panel and could run 240V anywhere in the house if needed. As you pointed out, they probably do have a 240V plug for the dryer, ergo they've got 240V service at the property, so they could wire the kitchen if there's no wiring already. Once again, practically nobody has only 120V service at their home.
        sbradford26 3y ago
        Yeah the only situation I can think of only 120v being available in a house is if it is a separate unit running off a 120v sub panel from the main building. The other option would be some off grid setups for like a tiny home might only run 120v. That is mostly because anything that would require 240v would be too power hungry to run off of the solar system.
        rootusrootus 3y ago
        That would be by choice, though. My mom's 110 year old house still has some circuits with cloth wiring. But it has a number of new (40-50 year old) circuits that are normal, grounded 5-15 120V. And the kitchen, basement, and garage have 240V receptacles. This is pretty much the same setup as any modern house.
    - sbradford26 3y ago
      Fundamentally the US just wires things differently. If a house has an electric or induction hob(Cooktop) it will be permanently wired for 240v. All your high power devices such as HVAC, ovens, cooktops, and EV chargers have dedicated lines at 240v for them. Every house in the US other than some super niche scenarios has 240V. Yes largely most everything is wired for 120V and only a few special lines at 240v but that is because those are the only things that really require more power.
      - ponector 3y ago
        While in Europe every regular socket has 230V but induction has 400V with 5-wired connection. It is amazing how fast it can boil water!
        bluGill 3y ago
        Power = V*A. You can get any given power output out of any voltage by following the formula. The number of wires is not a factor at all. Number of wires and voltage is a factor in cost of install of course, but nothing else.
        sbradford26 3y ago
        Yes European ones will run on higher voltage but largely they are equally powerful. US Version: https://www.bosch-home.com/us/productslist/cooking-baking/cooktops/induction-cooktops/NITP660SUC#/Tabs=section-technicalspecs/Togglebox=accessories/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.com/us/productslist/cooking-baking/co... UK Version: https://www.bosch-home.co.uk/product-list/cooking-baking/hobs/induction-hobs/PXX975KW1E#/Tabs=section-manuals/Togglebox=accessories/Togglebox=combinables/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.co.uk/product-list/cooking-baking/hob... Largely they have the same power output. While the total power available is actually higher for the US version at 12kW versus 11.1 kW for the UK version. That is because the US version needs to be on a 50 amp 240v circuit versus the max 16 amp circuit for the UK version. Even this Bosch one: https://www.bosch-home.co.uk/product-list/cooking-baking/hobs/venting-hobs/PXX875D67E#/Tabs=section-technical-overview/Togglebox=accessories/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.co.uk/product-list/cooking-baking/hob... Which clearly calls out 400v 3 phase has a lower power output at 7.4 kW. The max output to a single pan/pot typically is going to max out around 3.3-3.7 kW. I don't know the exact reasoning behind that but I assume it might cause issues with cookware if you go much higher than that.
  - deleted 3y ago
    [deleted]
  - johann8384 3y ago
    US Power is typically 240v split-phase, a single phase, not two phases. The transformer is 7200v to 240v. The Neutral line to your house is center tapped on the transformer giving you 120v from Hot to Neutral and 240v from Hot to Hot. I have L14-30 and L5-30 outlets throughout my house and property for example which lets me run higher voltage/amperage workloads more easily. My workshop has an isolation transformer which is 240v primary and 120v secondary. This allows me to run 80A of 120v "stuff" in my workshop but it's a 40A 240v load from the perspective of the main panel in the house.
    - mrcommentwriter 3y ago
      Interesting, I haven’t heard of anyone doing this before. What is the advantage? Assuming 120v loads are split reasonably equally between each leg of the 240v phase, the load will mostly be on the 240v circuit because both legs are connected in series. The neutral back to the transformer is only used to carry the difference between the 120v load on each leg of the phase, and also to keep the system grounded. I guess if you had a panel close to load capacity, as well as a single very high amp 120v device, the transformer could enable some more capacity by ensuring the load was distributed equally between the phases. However at that point a service upgrade would probably be necessary anyway based on the load calculation rules in the code. Also high amp 120v devices are quite rare as far as I know, so I was wondering why you went with this unusual setup.
- JadeNB 3y ago
  Do you know the answer? (Of course your remark makes sense even if you don't, but, if you do, then I'd love to know.)
- tyingq 3y ago
  The one explaining that Edison's DC system they were competing with, in the US, was using ~100v DC. And the public disinformation campaign characterizing AC as unsafe. Including attacking anything higher than approximately 100v as unsafe. That seemed like it answered the question to me.
- refurb 3y ago
  "Edison's lamps were 100V" is in one of the answers.
  - Ekaros 3y ago
    And to me this seems most obvious answers. With possibility that you had other resistive loads at that voltage already sold. And people would be rather gross if they had to replace them.
- wiredfool 3y ago
  So, not only is the UK 230v, it's also wired in a ring (i.e., your circuit isn't a branch from your junction box, it's a full loop). So, for a given power capacity, you can use much less copper. (from the wiki: https://en.wikipedia.org/wiki/Electrical_wiring_in_the_United_Kingdom https://en.wikipedia.org/wiki/Electrical_wiring_in_the_Unite...) UK fixed wiring circuits, unlike those found in almost all other countries, make widespread use of ring circuit designs, as well as radial circuit designs often seen in other countries. (This was one of the recommendations of the Electrical Installations Committee, convened in 1942 as part of the Post War Building Studies programme, which in 1944 determined that the ring final circuit offered a more efficient and lower cost method to support a greater number of sockets.[6]) It continues to be the usual wiring method for domestic and light commercial socket and device wiring in the UK. Lighting circuits, which typically have lower power requirements, are usually radially wired, confusingly sometimes called "loop" wiring. So, the why is: More power, less copper, and that's really useful when you're resource constrained because someone has declared war on you and is blockading your coast, or you're recovering from that.
- jqpabc123 3y ago
  There is not one single all encompassing answer. Safety was one significant concern. 230-240V is more likely to stop a person's heart. 220 is available in most US homes for specific cases where it is more practical. Speaking from experience, I don't think it is uncommon for a person to have been electrically shocked at some point in their lives --- often when they were a child.
  - wongarsu 3y ago
    Maybe common in the US. Europe takes plug and outlet design more serious (as a consequence of 230V), and while the UK plug and continental Europe's Schuko plug are very different both make it basically impossible to accidentally shock yourself.
    - jqpabc123 3y ago
      Plugs are only part of the safety issue. Wire insulation deteriorates over time. Rodents like to chew through it. Water can find it's way in through plumbing or roof leaks. Higher voltage is more likely to start a fire in these instances.
      - izacus 3y ago
        Are there any stats showing that Europe has more issues with electricutions and electrical fires?
        jqpabc123 3y ago
        According to the European Fire Safety Alliance: The total number of fires of electrical origin in the EU is estimated to be 273,000 per year. According to the US National Fire Protection Assocation: Fire departments responded to an estimated average of 46,700 home fires involving electrical failure or malfunction each year in 2015–2019. Stats aside, which do you think will cause a bigger spark, 110 or 220? https://www.europeanfiresafetyalliance.org/publications/white-paper-residential-electrical-safety/ https://www.europeanfiresafetyalliance.org/publications/whit... https://www.nfpa.org/News-and-Research/Data-research-and-tools/Electrical/Electrical https://www.nfpa.org/News-and-Research/Data-research-and-too...
noobermin 3y ago
I moved from the US to Singapore which uses 230, and that coupled with the humid environment makes things a lot less unsafe. That plus old HDB electrical work isn't always the best. Getting shocked and damaging electronics because a socket is lose is very common here, and can be life threatening. I never had to worry about this (at least as much). Floating ground here on the other hand is device or even life threatening which is a real issue as most chargers especially recent GaN ones do NOT have a ground prong.
- jraph 3y ago
  > that coupled with the humid environment makes things a lot less unsafe Safer? Why?
  - noobermin 3y ago
    When I am fly by night posting I do be using those double negatives. I meant less safe.
- zuppy 3y ago
  this is not an issue in Europe. what kind of plugs do you use in Singapore? the EU plug doesn't let you get shocked when pulling the cord. i am willing to bet it's because of that, not because of 220 vs 110. it has never been an issue in my life and i don't get shocked ... ever. edit: after a quick research i thing the reason is the socket: https://www.everyworks.com/reasons-why-your-singapore-electrical-socket-stopped-working/ https://www.everyworks.com/reasons-why-your-singapore-electr... we don't use this, we have a small hole inside ours and it's impossible to touch the live while the plug is connected
  - mnd999 3y ago
    Should be the same for type G, the pins are shielded such that it shouldn't be possible for them to have exposed metal and be live at the same time.
  - ketzu 3y ago
    Apparently they use british Type G plugs. ( https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#/media/File:World_map_of_electrical_mains_power_plug_types_used.svg https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#/me... )
mhandley 3y ago
As a Brit, the best thing about 230v is being able to run a 3kW kettle to make my tea. I took this for granted until I moved to the US.
- the_mitsuhiko 3y ago
  With induction stoves getting more popular that’s less of an issue nowadays.
  - swarnie 3y ago
    Still, putting the stove on to make a cup of tea seems wrong.
    - ThatMedicIsASpy 3y ago
      yeah but it is 5 times faster than a kettle
    - the_mitsuhiko 3y ago
      That seems purely emotional. An induction stove heats faster than a kettle at almost the same efficiency.
      - Tuna-Fish 3y ago
        No, it really does not. A typical induction stove has ~2kW of power on each element, and is ~20% less efficient at heating water than the resistive kettle. This makes it about half as fast at boiling water.
        oblio 3y ago
        You made me check and adjust my other comment: https://www.aeg.co.uk/kitchen/cooking/hobs/induction-hob/ikb64401fb/ https://www.aeg.co.uk/kitchen/cooking/hobs/induction-hob/ikb... 3.7kW for the main element. Also, why would it be less efficient? Due to the distance?
jraph 3y ago
(edit: this comment is quite useless, I need to leave it to keep the discussion understandable) Interested in the answer which I don't have. That said, UK is wired to the continent, which runs at 230V, 50 Hz. Everyone runs at the exact same frequency (same fluctuations) at any moment across the whole continent for technical reasons. (edit: UK is actually not synchronized with the continent, I didn't know that either). I guess having the about the same voltage as the rest of the continent is at least convenient (edit: apparently it's not exactly the same?). So I guess the question is US vs the European continent. Curious about the rest of America (North and South).
- mytailorisrich 3y ago
  It's almost North America (and some friends) vs rest of the world, really: https://en.wikipedia.org/wiki/Mains_electricity_by_country https://en.wikipedia.org/wiki/Mains_electricity_by_country
  - deleted 3y ago
    [deleted]
- HPsquared 3y ago
  UK interconnections to the continent are via HVDC links; the UK grid is not synchronous with the continental grid.
- ourlordcaffeine 3y ago
  The uk grid is not synchronized with the european grid, it is just HVDC interconnected. You are right about the european grid, it is synchronized
- baz00 3y ago
  Picking a small point from your comment I find interesting, the voltages vary considerably across Europe depending on all sorts of factors. In the UK at least it's from around 216 to 253 volts. Mine is sitting at 249 now.
- deleted 3y ago
  [deleted]
thrdbndndn 3y ago
TIL UK (or EU) uses 230V, not 220V like my country.
- oblio 3y ago
  Po-ta-toe - po-ta-toh. You can use 220V stuff with 230V plugs. There are fluctuations for each network, anyway. Which country are you talking about?
  - thrdbndndn 3y ago
    China.
- alex3305 3y ago
  In The Netherlands the allowed voltage tolerance is 10% by law. So everything between 207V and 253V should be fine. And we also had 220V until 1989.
- jonatron 3y ago
  UK actually uses 240V, which happens to be within +10% of 230V.
  - soneil 3y ago
    This is my favourite story about standardization. It used to be the continent used 220V, and the UK used 240V, until we standardized on 230V. The UK defines this as 230V -6% +10% (i.e. 216.2V – 253.0V), and nominal supply is 240V The continent defines this as 230V -10% +6% (i.e. 207.0V - 243.8V), and nominal supply is 220 or 230 by region. We called this harmonisation - in reality it's more like agreeing to disagree. We just fudged the tolerances until everyone was happy. (To put some context around this - most sites don't receive nominal supply. The actual voltage delivered depends on your distance to the local substation. Typically they over-deliver such that sites closest are a little over, sites furthest are a little under. If they actually delivered ±0%, sites at the edge of their network would be further from nominal. So end-user equipment should be built to expect variation.)
Egoist 3y ago
Some devices can also be more efficient when using 230V. Eg: PSUs https://electronics.stackexchange.com/questions/469913/computer-power-supplies-usually-have-higher-efficiency-on-230v-than-on-115v-why https://electronics.stackexchange.com/questions/469913/compu...
HPsquared 3y ago
The 50Hz and 60Hz is quite noticeable. I'm used to hearing mains hum at 50 Hz, so hearing it at 60 Hz sounds a little different. (You can sometimes hear it in audio recordings etc). 50 Hz is about a G, and 60 Hz is about a B-flat. Video comparison: https://youtu.be/pMtn-loUrg8 https://youtu.be/pMtn-loUrg8
- dvh 3y ago
  There was a video recently where YouTuber diodegonewild was fixing old power supply, he turned it on, listened to it and said "the transformer has DC offset on it, because it's humming at 50Hz, the magnetostriction doesn't care about polarity, healthy transformer hums at 100Hz, I think one of the diodes in bridge rectifier is bad" and he was right. https://www.youtube.com/watch?v=bWxS2njU-JI&t=355s https://www.youtube.com/watch?v=bWxS2njU-JI&t=355s
sph 3y ago
Relevant Technology Connections video: "The US electrical system is not 120V" https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4
PrimeMcFly 3y ago
Better yet why does the UK use those ridiculous cumbersome over-designed plugs? Or, even more curious, why are so many British authorities so bizarrely (to the point it's funny) protective over electricity, fining people and threatening to call police on people who try to charge their phones in train stations, for example?
- jraph 3y ago
  > cumbersome over-designed It's a pain they are not the same as the rest of Europe, but what is cumbersome and over-designed about UK plugs? Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway? (same distance between the 2 pins, but the pins are a bit thinner and the ground is in the opposite way).
  - PrimeMcFly 3y ago
    > It's a pain they are not the same as the rest of Europe, but what is cumbersome and over-designed about UK plugs? The size is definitely cumbersome. Look how much bigger they are than US/EU/AU plugs, basically any other countries plugs. I'd call having a fuse in the plug itself over-designed. > Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway? I have the same question about AU plugs. Literally the same as the US plugs (newer ones that don't have one side larger at least), just at an angle.
    - jonatron 3y ago
      The fuse in the plug is necessary to protect the wiring on ring circuits.
      - PrimeMcFly 3y ago
        Other countries get by just fine without it.
        wongarsu 3y ago
somat 3y ago
Really all residential connections in the US are 220V split phase. The nice thing about split phase is that it is easy to well... split and run two linked 110V circuits, so most houses will have a few 220V items(ovens, airconditioner) and the rest wired half with phase A the other half with phase B. all of our consumer items expect this 110V As to why split phase.... I am not really sure. Really, I wish a three phase residential had become normal instead. All the advantages of split phase but now your motors don't have to suck. I have heard a three phase residential connection is common in some parts of Germany, lucky bastards. One interesting side note is how the US last mile distribution layout is different than germany. The US uses a lot more smaller transformers, really one per street. while germany uses fewer larger transformers, one per neighborhood. not sure which one is better I bet the german layout is more efficient. but I will note it is a lot easier to keep spares and change out a small transformer.
- dfox 3y ago
  The split phase arrangement comes from Edison's DC systems. For large installations they found out that the losses were unacceptable and solved thet by running the lighting on 220V with sets of two 110V bulbs in series, usually combined with some somewhat funky wiring scheme in order to even more reduce the required wiring cross-section (it is somewhat reminiscent of later British ring mains construction and strikingly similar to various arrangements for powering long LED strips). This is also the reason why it is somewhat common for the US commercial lighting to use 220V. Three phase for residental connection is pretty much a standard everywhere with 230/400V system. Only small flats and really small houses get single phase. This is because the 230/400V output of the larger distribution transformer is inherently threephase and this gets distributed to essentially all the points of connection and the only reason why there are single phase residental connection is that they are slightly cheaper (both in terms of fixed monthly payment for capacity and in terms of initial installation costs). While in US the input to the typical residental pole/pedestal mounted local distribution transformer is already single phase, so you cannot really get three phases without running additional wires to the substation (and probably also having you own dedicated distribution transformer) and thus in a residantal area you are simply stuck with split-phase.
nzach 3y ago
My understanding is that this choice is a balancing act between having good efficiency for long distances transmissions (230v) and having a lower peak load in the grid (110v) for desely populated areas. But I'm no expert in this matter. Where I live (Brazil) is commom to have both. In the big cities you will find 110v and outside that you are more likely to find 220v. And yes, it is a pain if you move from a 220v city to a 110v one. But besides that most people don't care about having 2 standards. For anyone interested there is a semi-relevant TechnologyConnections video[0] where he discusses the popularity of kettles as way to heat water in the US. [0] - https://www.youtube.com/watch?v=_yMMTVVJI4c https://www.youtube.com/watch?v=_yMMTVVJI4c
- johann8384 3y ago
  The lines in your neighborhood that feed your house are 7200v, that goes into a transformer in the yard or on the pole which provides 240v to your house. Larger transmission lines are 38000 volts. There are other voltages in place as well.
ChrisArchitect 3y ago
(2014)
chociej 3y ago
Nobody's pointed it out yet, so I'll mention it: US voltage is 120 V (240 V phase to phase), not 110 V. And while 115 V is within service tolerances specified by ANSI C84.1 (114 V to 126 V), that's not the nominal value.
- ezfe 3y ago
  While it's true, the US does supply 120V±5%, appliances and equipment are operable on a much wider range. For example, my laptop charger is rated for 100-240V, which is not uncommon.
  - p1mrx 3y ago
    120V-5% is still greater than 110V. Power supplies are rated for 100V because that's the voltage in Japan. Though the tolerance would probably be useful for running a really long US extension cord.
    - MichaelZuo 3y ago
      Technically they function fine as low as 95V for the worst case scenario, if they're well built.
      - Moru 3y ago
        My old computer started burning in some internal cabling about 30 years ago. Turns out our power wasn't 230 V when the power company came and set up a machine to make a graph. Some times of the day it could be much lower and that made my ancient atari converted to a towerbox to burn the cable to the harddrive on booting.
      - Kirby64 3y ago
        Nothing to do with well built usually, just designed to work in all regions (specifically, Japan, which has 100V power for because of... reasons).
  - analog31 3y ago
getarofilter 3y ago
[dead]
lprd 3y ago
I spent about a decade in Europe and really enjoyed learning about how their electrical grid works. The ability to directly plug most appliances without needing to buy extra adapters was amazing. Boiling water also took half the amount of time. If memory serves, Thomas Edison used a 110v DC power supply to create a system of electricity for people. Meanwhile, Nikola Tesla invented the three-phase 240v Alternating Current (AC). Tesla was clearly a man ahead of his time (even by today's standards). tldr; Europe's grid is vastly superior to America's.
- gattilorenz 3y ago
  “The ability to directly plug most appliances without needing to buy extra adapters was amazing” unless you live in Italy, Switzerland, France (they have a socket with the ground sticking out I think), Poland, the UK, Denmark… it’s getting better and better due to the use of DC and the reduced need for grounding, though
- mixmastamyk 3y ago
  There’s a special plug for the oven, no adapter needed.
consp 3y ago
It's not all that weird though. Until the 1970's we had (in NL) 127 in some and 220v in other places which could either be 127v to ground, 220v to ground or 220v line-to-line. By around mid 2000's everything was switched to 230/400v for standardization in Europe, so it's not that long ago we still had some lower voltages.
rinron 3y ago
Here is a really great video that goes over the history https://www.youtube.com/watch?v=7yRGvMgieEU https://www.youtube.com/watch?v=7yRGvMgieEU Sometimes we think about the technical reasons and forget of the human and the developmental process that can sometimes have an effect on how things are today. spoiler for the video - its because too many 110v light bulbs were already in place by the time 220v ones were made and it was too expensive/difficult to change. kind of reminds me of why the US never switched to metric.
- rootusrootus 3y ago
  > why the US never switched to metric Pretty much exactly why the UK didn't. What, you say? The UK uses metric, right? Yes, in much the same way as the US does. Officially, the US gov't stance is metric. And in technical areas as well as much of the consumer space, metric is everywhere. What isn't really changing is layperson preference for units. People are comfortable with feet, yards, miles, Fahrenheit, etc. Just like the UK still using miles, and many normal people measuring weight in stones. Inertia is a pretty important consideration, and not invalid. Imagine trying to convince the UK to drive on the correct side of the road at this point. ;-)
throw0101b 3y ago
Kathy Loves Physics & History did a video on this, and the reason is basically legacy: * https://www.youtube.com/watch?v=7yRGvMgieEU https://www.youtube.com/watch?v=7yRGvMgieEU Edison originally purchased others' dynamos, especially Wallace-Farmer, which was 110V (DC): * https://americanhistory.si.edu/collections/search/object/nmah_705221 https://americanhistory.si.edu/collections/search/object/nma... * https://en.wikipedia.org/wiki/Moses_G._Farmer https://en.wikipedia.org/wiki/Moses_G._Farmer So Edison's long-legged Mary-Ann was also 110V: * https://www.collectorsweekly.com/stories/82967-thomas-edison-dynamo-long-legged-mary-a https://www.collectorsweekly.com/stories/82967-thomas-edison... * https://edison.rutgers.edu/life-of-edison/inventions?view=article&id=530:electric-generator&catid=91 https://edison.rutgers.edu/life-of-edison/inventions?view=ar... * https://americanhistory.si.edu/collections/search/object/nmah_1287625 https://americanhistory.si.edu/collections/search/object/nma... Light bulbs in the early 1900s were first designed for lower voltages, and the grid slowly raised things over time, but at some point they couldn't go any higher because it would start blowing things, so they were 'stuck' in the 110-120V range.
vonwoodson 3y ago
Because, Freedom. And, because America. **=== Now, I'm going to go talk to My Fellow 'Mericans about continuing to not use the metric system.
- otherme123 3y ago
  I am european. Regarding to the metric system, IMO americans are wrong. But regarding to electricity, americans have it better than Europe: France, UK, Italy, Switzerland, Denmark and Germany have their own sockets, and that after a recent spread of the german Schuko. We shouldn't lecture americans about changing things to use a standard.
  - vonwoodson 3y ago
    There's nothing "wrong" about being The Best! #FREEDOM #TheseColorsDontRun #Merica
bloomingeek 3y ago
"In some rare situations 220V might be more dangerous to touch." Uh huh, here's an idea, go ahead and test that out for yourself!
- Faaak 3y ago
  And with 30mA GFCIs, the risk is greatly diminished
1970-01-01 3y ago
>Why do they use different frequencies like 50Hz, 60Hz? I've never found a technical answer for the 50Hz vs 60Hz question. It does seem to be an arbitrary standard.
- michaelrpeskin 3y ago
  My guess: in the old days when electricity was new, power conversion was done with Rotary converters which were basically a fused motor-generator. To change voltage you had different winding and number of poles. So if you were at 60 Hz, you have the magic of being divisible by a lot of numbers and you could easily go up down by common integer values. Then when Europe was standardizing, they wanted to be all metric, and 50 was close enough to 60 and still could become 100 by doubling. I don't know, those are just pure guesses. I think when you come from the engineering/tinkering side of things, you like units with easy integer fractions (12 inches in a foot is really easy to work with at human scale). When you come from the science side of things, you like easy decimals and that's why metric wins there.
tomohawk 3y ago
In the US, you can have electric receptacles in bathrooms. In fact, code requires it. You can plug in 120V electronics and appliances no big deal. In the UK, this is not allowed because 240V is not a good idea in bathrooms.
- kypro 3y ago
  Most bathrooms in UK hotels will have two pin 115v & 230v outlets for shavers. You can get them installed in homes too I believe, but most residential properties don't have them. They really are just for shavers though. You can't run anything high power without blowing the fuse. I believe Americans often use hairdryers in bathrooms. We definitely can't do that. That said, we do have electric showers in UK bathrooms but legally those need to have a kill switch installed.
- tzs 3y ago
  But it is allowed in most of the rest of Europe. I believe they do require those to have GFCI (as does the US since 1975). Does the UK disallow them even with GFCI?
hot_gril 3y ago
Every comment in this thread is mentioning a different angle of advantage/disadvantage between the two. I've given up on determining the winner, but that's ok, I'm just learning a lot about home power distribution.
- mrguyorama 3y ago
  There is no winner. It's a simple API, with many correct answers. The US ossified on it's system, and different European countries did the same. It's just a standard "Emacs vs VIM" flamewar.
  - rootusrootus 3y ago
    > The US ossified on it's system Though it is crass, I'll say it. A silver lining to the tremendous infrastructure damage caused by world wars in Europe is that ossification was interrupted.
  - hot_gril 3y ago
    Well if you compare it to emacs vs vim, that's making me think there is a correct answer.
    - bluGill 3y ago
      There is, but you are wrong... Hang on, let me go find my old flame war cheat sheet I need to throw a few more insults at you. /s
- rootusrootus 3y ago
  > I've given up on determining the winner That's because there is no winner. Nobody is doing something in the US that is impossible in Europe, or vice versa. There are upsides to both approaches, and different trade-offs, but everyone is getting enough power.
- darknavi 3y ago
  Tom Scott has a fun video not on voltage but on the merits of the wall sockets them selves: https://www.youtube.com/watch?v=UEfP1OKKz_Q https://www.youtube.com/watch?v=UEfP1OKKz_Q
codedokode 3y ago
I would like the voltage to be lowered even more, to 70 Volts. The reason is that 240V is very dangerous and can easily kill a human. But it seems governments care only about saving aluminium in wires rather than lives.
- mcpackieh 3y ago
  > But it seems governments care only about saving aluminium in wires rather than lives. That's needlessly inflammatory. Both the US and UK governments have numerous electrical standards and regulations designed to keep people safe despite unsafe power levels in residential wiring. You might argue that they aren't doing enough in this regard, but to say they only care about saving metal just isn't true.
- mdekkers 3y ago
  Death by electrocution is incredibly rare in the EU, what are you talking about? Data, or hold your peace.
  - codedokode 3y ago
    Here is a recent case, for example [1] [1] https://www.dailymail.co.uk/news/article-12042495/Italian-girl-16-electrocuted-death-bath-phone-friend.html https://www.dailymail.co.uk/news/article-12042495/Italian-gi...
- vel0city 3y ago
  > But it seems governments care only about saving aluminium in wires rather than lives. I go even further on trying to save aluminum in my wires by not using any aluminum wires. Aluminum wiring is pretty rare in the US and largely considered a nightmare to work with.
  - rootusrootus 3y ago
    > Aluminum wiring is pretty rare in the US and largely considered a nightmare to work with. Yeah, you basically only find aluminum wiring used today for the feeder, and for circuits larger than 60A. And that's mainly due to cost, copper is pretty expensive.
perfectstorm 3y ago
i wish 240V was more common. i can't charge my EV at a reasonable rate and it would cost me $15k+ to install a 240V in my detached garage (requires trenching).
- tzs 3y ago
  Could you do the trenching yourself? I don't know where you are, but in the US a walk-behind trencher rents for under $500 per day [1] [2] [3] [4]. [1] https://www.sunbeltrentals.com/equipment-rental/earth-moving/trenchers/walk-behind-trenchers/ https://www.sunbeltrentals.com/equipment-rental/earth-moving... [2] https://www.compactpowerrents.com/rental-equipment/trencher/24-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/... [3] https://www.compactpowerrents.com/rental-equipment/trencher/36-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/... [4] https://www.compactpowerrents.com/rental-equipment/trencher/48-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/...
- deleted 3y ago
  [deleted]
- Anon_Forever 3y ago
  >i wish 240V was more common More common where? Your main service panel is 240V. Do you only have a single 120V circuit feeding your garage?
jahnu 3y ago
Even stranger than that, Japan has two grids, one at 50Hz and one at 60Hz!
- askvictor 3y ago
  ...which were completely isolated, until Fukushima led to power shortages so they hurriedly linked /are linking the two with DC interconnects.
kelnos 3y ago
I found it somewhat funny that the question included: >Explain me with calculation. As with many things related to technology, decisions are very often made for seemingly arbitrary (or political, or economic, or competitive-advantage) reasons, not because of some calculation that was done that proved a decision optimal.
hooch 3y ago
How does ChatGPT come anywhere close in usefulness compared to the breadth and fan-out of facts, opinion, supports and counter-arguments offered by this format?
sleepybrett 3y ago
similar story to railroad gauges
temporallobe 3y ago
I’ve lived in UK, Europe, and the US and I don’t really see a problem with either system. The 120V system is perfectly sufficient for most cases, even refrigerators and other large appliances. I suppose the one advantage a 220V system has is that you can put a stove or dryer anywhere, and you can run certain appliances, such as steamers and irons with way more power. On the other hand I find the UK’s plugs to be comically large compared to the US’s petite counterparts. Some European houses even have a few 3-phase 380V outlets for heavy duty equipment, which would be exceedingly rare in the US.
- rekoil 3y ago
  > Some European houses even have a few 3-phase 380V outlets for heavy duty equipment, which would be exceedingly rare in the US. My European 50m² apartment has two.
dim13 3y ago
Old joke: why USA use 110V and UdSSR 220V? Answer: because half of it will be stollen in transition anyway.
ralferoo 3y ago
The world is pretty standardised into these two now, but that can't always have been the case. In the early 1980s, my dad found an old valve keyboard / organ thing at some jumble or car-boot sale that probably dated at least from the 1950s, and being curious I used to regularly take it to bits. One thing that was weird is that there was an input voltage selector on it, but it was a round thing with contacts arranged in a circle and a plug that would bridge one contact to the centre contact. The range of input voltages was 60VAC to 240VAC, and there were probably 10 or 12 different voltages in that range. Unfortunately, this was also how I destroyed the keyboard part (but not the separate valve amplifier that I continued to use for at least another decade) because the 60VAC was next to the 240VAC and I accidentally bridged it to 60VAC and fed it 240VAC. All the valves were powered at 4x what they should have been and there was a bang and nothing worked after that. In retrospect, I should probably have kept it as probably only a few valves took the brunt of power surge, but even then valves were hard to get hold of and these weren't all the same (my memory is fuzzy, but there were probably 30+ valves in the keyboard, I only pulled a few to look at them and they were obviously different), so we just decided it was something that didn't need to be repaired. But anyway, long story aside - there must have been some demand for such a wide range of input voltages for the power supply, or they wouldn't have come up with a selector switch with so many possible options.
ralferoo 3y ago
Oh, another fun fact... Historically, the UK was 240V and Europe was 220V. This was later standardised across Europe as nominal 230V +- 10%, and AFAIK both UK and mainland Europe carried on as they were without actually changing anything!
stikypad 3y ago
220 VAC allows higher gauge (thinner) wires for the same wattage consumption and more watts per circuit for the same amperage (more powerful appliances and/or more concurrent appliances without tripping a breaker). And the UK in particular has far safer plugs than the US, with a fuse in every plug, partially insulated plug leads, and blocking shutters on the sockets. So basically we could use less copper, have safer homes, and simplify power supply design since we (and a handful of other holdouts) are basically the only countries using 100-120 VAC rather than 210-230 VAC, which would lower costs and reduce waste.

207 points by dilawar 3y ago

There were many factually correct, and even historically interesting responses. But not a single response answered the question.

antegamisou 3y ago
Welcome to *.stackexchange.com
wongarsu 3y ago
I'm not sure there is a good answer, beyond "the US stuck with Edison's 110V, Europe went with 230V because it's cheaper". Both 110V and 230V are reasonable choices. And of course technically the US primarily uses 230V split between two phases. But Europe mostly uses 3-phase 400V, with each phase delivering 230V (because phases are 120° offset to each other), so then we are just talking about 230V vs 400V, and two vs three phases.
- oblio 3y ago
  > Both 110V and 230V are reasonable choices. Are they, though? With modern appliances, power requirements are going up and 110V is struggling to keep up. One example would be an induction hob. I know that technically US homes can access 230V but they aren't wired for that, probably 99% are wired just for 110V except for maybe a few special lines.
  - wongarsu 3y ago
    Interestingly enough, European oven/hob combos mostly run on 400V 3-phase power. Same for many tankless water heaters. That's certainly one advantage of 230V per phase. It's probably also one factor in the decision to power things by gas vs electric.
    - rootusrootus 3y ago
      But are they more powerful? AFAIK it's pretty common for a European range to be in the 7000-10000 watt range. That's also normal in the US on single phase 240V. And I can go buy a 36000 watt tankless water heater from Home Depot. I think it's a wash, either system can deliver however much power you need. The reason for gas in the US is because people like it. It's been seen as upscale for decades to have a gas cooktop. It also helps that gas water heaters don't require electricity and work in an outage. Our residential natural gas distribution network is extensive and reliable, and it's pretty straightforward to use the same appliances on propane for people out in the sticks.
      - vel0city 3y ago
        Depending on the market it can also be cheaper per BTU to heat with gas than with electricity, at least resistive heating. Heat pumps are starting to challenge that math, but with higher upfront costs and more complexity as tradeoffs.
  - michaelt 3y ago
    > With modern appliances, power requirements are going up Things like lightbulbs and TVs and computers and refrigerators are using less power than ever before. Of course, if people are buying electric cars or replacing gas furnaces with electric heat pumps, then you're right on that side of things.
    - oblio 3y ago
      > Things like lightbulbs and TVs and computers and refrigerators are using less power than ever before. Are they, though? Lightbulbs, sure, we won with LEDs. But TVs, especially the huge, high brightness ones we have nowadays? And with the extra computing needed? Computers, same, I only see power usage going up. I mean PCs, we're not comparing things with mainframes here :-) Refrigerators: are they really more efficient? Now add: heat pump, induction stove, electric oven, more powerful AC, humidifiers/dehumidifiers, etc.
      - michaelt 3y ago
        Compared to the age of CRTs, modern TVs are much more power efficient. And compared to the age of the Pentium 4 with its 100W+ TDP, laptops now outsell desktop computers by a long way. (I would agree that things like high-end gaming GPUs are using more power than ever before - but they're also a much smaller % of sales than ever before)
        oblio 3y ago
        > Compared to the age of CRTs, modern TVs are much more power efficient. According to the internet a CRT TV used to use about 100W, while a big LCD TV can use more. Regarding desktops, don't forget that these days we have many more electronic device in a home. Smart speakers, home media devices, consoles, etc, etc. Electronics probably use, in aggregate 5-10x what the old family PC used to use, I'd imagine.
        selectodude 3y ago
        A 32” Sony trinitron would pull down about 200W. An 85” LCD will pull down about 150W.
  - wil421 3y ago
    Laundry, stove, and ovens use 240V outlets (assuming no gas). It’s not very common but I know a few people with wood working tools who have installed 240v outlets. Wood framed houses make it easy to change wiring. To change my gas stove/oven back to 240v induction would be a 15 foot run of romex, a new outlet, and probably an updated circuit breaker. Possible for a DIYer to do.
  - vel0city 3y ago
    Every US home I've lived in had 240V access in the kitchen for appliances like electric ranges. They absolutely are wired for that. Practically nobody's house only has 120V.
    - gibspaulding 3y ago
      It sounds like you've always lived in relatively new/high end houses then. Older houses might have a dedicated 240 plug for the dryer and the stove if they're not natural gass, but for everything else there are plenty of homes full of ungrounded 10 amp 120v circuits.
      - vel0city 3y ago
        My current house was built in '82. Is that a new house? That's 41 years old at this point. Its a pretty average single family suburban build for the time, not anything especially fancy even for its day. Loads of houses we looked at in the area were built in the 70s and 60s and often had electric 240V appliances in the kitchen. That's about 60 years old, is that a new? A single car garage 1500sqft 3bdr house in a suburb sound like a high end house? And yeah, my house is full of 120V circuits, but once again the house has 240V at the panel and could run 240V anywhere in the house if needed. As you pointed out, they probably do have a 240V plug for the dryer, ergo they've got 240V service at the property, so they could wire the kitchen if there's no wiring already. Once again, practically nobody has only 120V service at their home.
        sbradford26 3y ago
        Yeah the only situation I can think of only 120v being available in a house is if it is a separate unit running off a 120v sub panel from the main building. The other option would be some off grid setups for like a tiny home might only run 120v. That is mostly because anything that would require 240v would be too power hungry to run off of the solar system.
      - rootusrootus 3y ago
        That would be by choice, though. My mom's 110 year old house still has some circuits with cloth wiring. But it has a number of new (40-50 year old) circuits that are normal, grounded 5-15 120V. And the kitchen, basement, and garage have 240V receptacles. This is pretty much the same setup as any modern house.
  - sbradford26 3y ago
    Fundamentally the US just wires things differently. If a house has an electric or induction hob(Cooktop) it will be permanently wired for 240v. All your high power devices such as HVAC, ovens, cooktops, and EV chargers have dedicated lines at 240v for them. Every house in the US other than some super niche scenarios has 240V. Yes largely most everything is wired for 120V and only a few special lines at 240v but that is because those are the only things that really require more power.
    - ponector 3y ago
      While in Europe every regular socket has 230V but induction has 400V with 5-wired connection. It is amazing how fast it can boil water!
      - bluGill 3y ago
        Power = V*A. You can get any given power output out of any voltage by following the formula. The number of wires is not a factor at all. Number of wires and voltage is a factor in cost of install of course, but nothing else.
      - sbradford26 3y ago
        Yes European ones will run on higher voltage but largely they are equally powerful. US Version: https://www.bosch-home.com/us/productslist/cooking-baking/cooktops/induction-cooktops/NITP660SUC#/Tabs=section-technicalspecs/Togglebox=accessories/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.com/us/productslist/cooking-baking/co... UK Version: https://www.bosch-home.co.uk/product-list/cooking-baking/hobs/induction-hobs/PXX975KW1E#/Tabs=section-manuals/Togglebox=accessories/Togglebox=combinables/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.co.uk/product-list/cooking-baking/hob... Largely they have the same power output. While the total power available is actually higher for the US version at 12kW versus 11.1 kW for the UK version. That is because the US version needs to be on a 50 amp 240v circuit versus the max 16 amp circuit for the UK version. Even this Bosch one: https://www.bosch-home.co.uk/product-list/cooking-baking/hobs/venting-hobs/PXX875D67E#/Tabs=section-technical-overview/Togglebox=accessories/Togglebox=manuals/Togglebox=accessoriesOthers/ https://www.bosch-home.co.uk/product-list/cooking-baking/hob... Which clearly calls out 400v 3 phase has a lower power output at 7.4 kW. The max output to a single pan/pot typically is going to max out around 3.3-3.7 kW. I don't know the exact reasoning behind that but I assume it might cause issues with cookware if you go much higher than that.
- deleted 3y ago
  [deleted]
- johann8384 3y ago
  US Power is typically 240v split-phase, a single phase, not two phases. The transformer is 7200v to 240v. The Neutral line to your house is center tapped on the transformer giving you 120v from Hot to Neutral and 240v from Hot to Hot. I have L14-30 and L5-30 outlets throughout my house and property for example which lets me run higher voltage/amperage workloads more easily. My workshop has an isolation transformer which is 240v primary and 120v secondary. This allows me to run 80A of 120v "stuff" in my workshop but it's a 40A 240v load from the perspective of the main panel in the house.
  - mrcommentwriter 3y ago
    Interesting, I haven’t heard of anyone doing this before. What is the advantage? Assuming 120v loads are split reasonably equally between each leg of the 240v phase, the load will mostly be on the 240v circuit because both legs are connected in series. The neutral back to the transformer is only used to carry the difference between the 120v load on each leg of the phase, and also to keep the system grounded. I guess if you had a panel close to load capacity, as well as a single very high amp 120v device, the transformer could enable some more capacity by ensuring the load was distributed equally between the phases. However at that point a service upgrade would probably be necessary anyway based on the load calculation rules in the code. Also high amp 120v devices are quite rare as far as I know, so I was wondering why you went with this unusual setup.
JadeNB 3y ago
Do you know the answer? (Of course your remark makes sense even if you don't, but, if you do, then I'd love to know.)
tyingq 3y ago
The one explaining that Edison's DC system they were competing with, in the US, was using ~100v DC. And the public disinformation campaign characterizing AC as unsafe. Including attacking anything higher than approximately 100v as unsafe. That seemed like it answered the question to me.
refurb 3y ago
"Edison's lamps were 100V" is in one of the answers.
- Ekaros 3y ago
  And to me this seems most obvious answers. With possibility that you had other resistive loads at that voltage already sold. And people would be rather gross if they had to replace them.
wiredfool 3y ago
So, not only is the UK 230v, it's also wired in a ring (i.e., your circuit isn't a branch from your junction box, it's a full loop). So, for a given power capacity, you can use much less copper. (from the wiki: https://en.wikipedia.org/wiki/Electrical_wiring_in_the_United_Kingdom https://en.wikipedia.org/wiki/Electrical_wiring_in_the_Unite...) UK fixed wiring circuits, unlike those found in almost all other countries, make widespread use of ring circuit designs, as well as radial circuit designs often seen in other countries. (This was one of the recommendations of the Electrical Installations Committee, convened in 1942 as part of the Post War Building Studies programme, which in 1944 determined that the ring final circuit offered a more efficient and lower cost method to support a greater number of sockets.[6]) It continues to be the usual wiring method for domestic and light commercial socket and device wiring in the UK. Lighting circuits, which typically have lower power requirements, are usually radially wired, confusingly sometimes called "loop" wiring. So, the why is: More power, less copper, and that's really useful when you're resource constrained because someone has declared war on you and is blockading your coast, or you're recovering from that.
jqpabc123 3y ago
There is not one single all encompassing answer. Safety was one significant concern. 230-240V is more likely to stop a person's heart. 220 is available in most US homes for specific cases where it is more practical. Speaking from experience, I don't think it is uncommon for a person to have been electrically shocked at some point in their lives --- often when they were a child.
- wongarsu 3y ago
  Maybe common in the US. Europe takes plug and outlet design more serious (as a consequence of 230V), and while the UK plug and continental Europe's Schuko plug are very different both make it basically impossible to accidentally shock yourself.
  - jqpabc123 3y ago
    Plugs are only part of the safety issue. Wire insulation deteriorates over time. Rodents like to chew through it. Water can find it's way in through plumbing or roof leaks. Higher voltage is more likely to start a fire in these instances.
    - izacus 3y ago
      Are there any stats showing that Europe has more issues with electricutions and electrical fires?
      - jqpabc123 3y ago
        According to the European Fire Safety Alliance: The total number of fires of electrical origin in the EU is estimated to be 273,000 per year. According to the US National Fire Protection Assocation: Fire departments responded to an estimated average of 46,700 home fires involving electrical failure or malfunction each year in 2015–2019. Stats aside, which do you think will cause a bigger spark, 110 or 220? https://www.europeanfiresafetyalliance.org/publications/white-paper-residential-electrical-safety/ https://www.europeanfiresafetyalliance.org/publications/whit... https://www.nfpa.org/News-and-Research/Data-research-and-tools/Electrical/Electrical https://www.nfpa.org/News-and-Research/Data-research-and-too...

noobermin 3y ago

I moved from the US to Singapore which uses 230, and that coupled with the humid environment makes things a lot less unsafe. That plus old HDB electrical work isn't always the best. Getting shocked and damaging electronics because a socket is lose is very common here, and can be life threatening. I never had to worry about this (at least as much). Floating ground here on the other hand is device or even life threatening which is a real issue as most chargers especially recent GaN ones do NOT have a ground prong.

jraph 3y ago
> that coupled with the humid environment makes things a lot less unsafe Safer? Why?
- noobermin 3y ago
  When I am fly by night posting I do be using those double negatives. I meant less safe.
zuppy 3y ago
this is not an issue in Europe. what kind of plugs do you use in Singapore? the EU plug doesn't let you get shocked when pulling the cord. i am willing to bet it's because of that, not because of 220 vs 110. it has never been an issue in my life and i don't get shocked ... ever. edit: after a quick research i thing the reason is the socket: https://www.everyworks.com/reasons-why-your-singapore-electrical-socket-stopped-working/ https://www.everyworks.com/reasons-why-your-singapore-electr... we don't use this, we have a small hole inside ours and it's impossible to touch the live while the plug is connected
- mnd999 3y ago
  Should be the same for type G, the pins are shielded such that it shouldn't be possible for them to have exposed metal and be live at the same time.
- ketzu 3y ago
  Apparently they use british Type G plugs. ( https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#/media/File:World_map_of_electrical_mains_power_plug_types_used.svg https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#/me... )

mhandley 3y ago

As a Brit, the best thing about 230v is being able to run a 3kW kettle to make my tea. I took this for granted until I moved to the US.

the_mitsuhiko 3y ago
With induction stoves getting more popular that’s less of an issue nowadays.
- swarnie 3y ago
  Still, putting the stove on to make a cup of tea seems wrong.
  - ThatMedicIsASpy 3y ago
    yeah but it is 5 times faster than a kettle
  - the_mitsuhiko 3y ago
    That seems purely emotional. An induction stove heats faster than a kettle at almost the same efficiency.
    - Tuna-Fish 3y ago
      No, it really does not. A typical induction stove has ~2kW of power on each element, and is ~20% less efficient at heating water than the resistive kettle. This makes it about half as fast at boiling water.
      - oblio 3y ago
        You made me check and adjust my other comment: https://www.aeg.co.uk/kitchen/cooking/hobs/induction-hob/ikb64401fb/ https://www.aeg.co.uk/kitchen/cooking/hobs/induction-hob/ikb... 3.7kW for the main element. Also, why would it be less efficient? Due to the distance?

jraph 3y ago

(edit: this comment is quite useless, I need to leave it to keep the discussion understandable) Interested in the answer which I don't have. That said, UK is wired to the continent, which runs at 230V, 50 Hz. Everyone runs at the exact same frequency (same fluctuations) at any moment across the whole continent for technical reasons. (edit: UK is actually not synchronized with the continent, I didn't know that either). I guess having the about the same voltage as the rest of the continent is at least convenient (edit: apparently it's not exactly the same?). So I guess the question is US vs the European continent. Curious about the rest of America (North and South).

mytailorisrich 3y ago
It's almost North America (and some friends) vs rest of the world, really: https://en.wikipedia.org/wiki/Mains_electricity_by_country https://en.wikipedia.org/wiki/Mains_electricity_by_country
- deleted 3y ago
  [deleted]
HPsquared 3y ago
UK interconnections to the continent are via HVDC links; the UK grid is not synchronous with the continental grid.
ourlordcaffeine 3y ago
The uk grid is not synchronized with the european grid, it is just HVDC interconnected. You are right about the european grid, it is synchronized
baz00 3y ago
Picking a small point from your comment I find interesting, the voltages vary considerably across Europe depending on all sorts of factors. In the UK at least it's from around 216 to 253 volts. Mine is sitting at 249 now.
deleted 3y ago
[deleted]

thrdbndndn 3y ago

TIL UK (or EU) uses 230V, not 220V like my country.

oblio 3y ago
Po-ta-toe - po-ta-toh. You can use 220V stuff with 230V plugs. There are fluctuations for each network, anyway. Which country are you talking about?
- thrdbndndn 3y ago
  China.
alex3305 3y ago
In The Netherlands the allowed voltage tolerance is 10% by law. So everything between 207V and 253V should be fine. And we also had 220V until 1989.
jonatron 3y ago
UK actually uses 240V, which happens to be within +10% of 230V.
- soneil 3y ago
  This is my favourite story about standardization. It used to be the continent used 220V, and the UK used 240V, until we standardized on 230V. The UK defines this as 230V -6% +10% (i.e. 216.2V – 253.0V), and nominal supply is 240V The continent defines this as 230V -10% +6% (i.e. 207.0V - 243.8V), and nominal supply is 220 or 230 by region. We called this harmonisation - in reality it's more like agreeing to disagree. We just fudged the tolerances until everyone was happy. (To put some context around this - most sites don't receive nominal supply. The actual voltage delivered depends on your distance to the local substation. Typically they over-deliver such that sites closest are a little over, sites furthest are a little under. If they actually delivered ±0%, sites at the edge of their network would be further from nominal. So end-user equipment should be built to expect variation.)

Egoist 3y ago

Some devices can also be more efficient when using 230V. Eg: PSUs https://electronics.stackexchange.com/questions/469913/computer-power-supplies-usually-have-higher-efficiency-on-230v-than-on-115v-why https://electronics.stackexchange.com/questions/469913/compu...

HPsquared 3y ago

The 50Hz and 60Hz is quite noticeable. I'm used to hearing mains hum at 50 Hz, so hearing it at 60 Hz sounds a little different. (You can sometimes hear it in audio recordings etc). 50 Hz is about a G, and 60 Hz is about a B-flat. Video comparison: https://youtu.be/pMtn-loUrg8 https://youtu.be/pMtn-loUrg8

dvh 3y ago
There was a video recently where YouTuber diodegonewild was fixing old power supply, he turned it on, listened to it and said "the transformer has DC offset on it, because it's humming at 50Hz, the magnetostriction doesn't care about polarity, healthy transformer hums at 100Hz, I think one of the diodes in bridge rectifier is bad" and he was right. https://www.youtube.com/watch?v=bWxS2njU-JI&t=355s https://www.youtube.com/watch?v=bWxS2njU-JI&t=355s

sph 3y ago

Relevant Technology Connections video: "The US electrical system is not 120V" https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4

PrimeMcFly 3y ago

Better yet why does the UK use those ridiculous cumbersome over-designed plugs? Or, even more curious, why are so many British authorities so bizarrely (to the point it's funny) protective over electricity, fining people and threatening to call police on people who try to charge their phones in train stations, for example?

jraph 3y ago
> cumbersome over-designed It's a pain they are not the same as the rest of Europe, but what is cumbersome and over-designed about UK plugs? Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway? (same distance between the 2 pins, but the pins are a bit thinner and the ground is in the opposite way).
- PrimeMcFly 3y ago
  > It's a pain they are not the same as the rest of Europe, but what is cumbersome and over-designed about UK plugs? The size is definitely cumbersome. Look how much bigger they are than US/EU/AU plugs, basically any other countries plugs. I'd call having a fuse in the plug itself over-designed. > Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway? I have the same question about AU plugs. Literally the same as the US plugs (newer ones that don't have one side larger at least), just at an angle.
  - jonatron 3y ago
    The fuse in the plug is necessary to protect the wiring on ring circuits.
    - PrimeMcFly 3y ago
      Other countries get by just fine without it.
      - wongarsu 3y ago

somat 3y ago

Really all residential connections in the US are 220V split phase. The nice thing about split phase is that it is easy to well... split and run two linked 110V circuits, so most houses will have a few 220V items(ovens, airconditioner) and the rest wired half with phase A the other half with phase B. all of our consumer items expect this 110V As to why split phase.... I am not really sure. Really, I wish a three phase residential had become normal instead. All the advantages of split phase but now your motors don't have to suck. I have heard a three phase residential connection is common in some parts of Germany, lucky bastards. One interesting side note is how the US last mile distribution layout is different than germany. The US uses a lot more smaller transformers, really one per street. while germany uses fewer larger transformers, one per neighborhood. not sure which one is better I bet the german layout is more efficient. but I will note it is a lot easier to keep spares and change out a small transformer.

dfox 3y ago
The split phase arrangement comes from Edison's DC systems. For large installations they found out that the losses were unacceptable and solved thet by running the lighting on 220V with sets of two 110V bulbs in series, usually combined with some somewhat funky wiring scheme in order to even more reduce the required wiring cross-section (it is somewhat reminiscent of later British ring mains construction and strikingly similar to various arrangements for powering long LED strips). This is also the reason why it is somewhat common for the US commercial lighting to use 220V. Three phase for residental connection is pretty much a standard everywhere with 230/400V system. Only small flats and really small houses get single phase. This is because the 230/400V output of the larger distribution transformer is inherently threephase and this gets distributed to essentially all the points of connection and the only reason why there are single phase residental connection is that they are slightly cheaper (both in terms of fixed monthly payment for capacity and in terms of initial installation costs). While in US the input to the typical residental pole/pedestal mounted local distribution transformer is already single phase, so you cannot really get three phases without running additional wires to the substation (and probably also having you own dedicated distribution transformer) and thus in a residantal area you are simply stuck with split-phase.

nzach 3y ago

My understanding is that this choice is a balancing act between having good efficiency for long distances transmissions (230v) and having a lower peak load in the grid (110v) for desely populated areas. But I'm no expert in this matter. Where I live (Brazil) is commom to have both. In the big cities you will find 110v and outside that you are more likely to find 220v. And yes, it is a pain if you move from a 220v city to a 110v one. But besides that most people don't care about having 2 standards. For anyone interested there is a semi-relevant TechnologyConnections video[0] where he discusses the popularity of kettles as way to heat water in the US. [0] - https://www.youtube.com/watch?v=_yMMTVVJI4c https://www.youtube.com/watch?v=_yMMTVVJI4c

johann8384 3y ago
The lines in your neighborhood that feed your house are 7200v, that goes into a transformer in the yard or on the pole which provides 240v to your house. Larger transmission lines are 38000 volts. There are other voltages in place as well.

ChrisArchitect 3y ago

(2014)

chociej 3y ago

Nobody's pointed it out yet, so I'll mention it: US voltage is 120 V (240 V phase to phase), not 110 V. And while 115 V is within service tolerances specified by ANSI C84.1 (114 V to 126 V), that's not the nominal value.

ezfe 3y ago
While it's true, the US does supply 120V±5%, appliances and equipment are operable on a much wider range. For example, my laptop charger is rated for 100-240V, which is not uncommon.
- p1mrx 3y ago
  120V-5% is still greater than 110V. Power supplies are rated for 100V because that's the voltage in Japan. Though the tolerance would probably be useful for running a really long US extension cord.
  - MichaelZuo 3y ago
    Technically they function fine as low as 95V for the worst case scenario, if they're well built.
    - Moru 3y ago
      My old computer started burning in some internal cabling about 30 years ago. Turns out our power wasn't 230 V when the power company came and set up a machine to make a graph. Some times of the day it could be much lower and that made my ancient atari converted to a towerbox to burn the cable to the harddrive on booting.
    - Kirby64 3y ago
      Nothing to do with well built usually, just designed to work in all regions (specifically, Japan, which has 100V power for because of... reasons).
- analog31 3y ago

getarofilter 3y ago

[dead]

lprd 3y ago

I spent about a decade in Europe and really enjoyed learning about how their electrical grid works. The ability to directly plug most appliances without needing to buy extra adapters was amazing. Boiling water also took half the amount of time. If memory serves, Thomas Edison used a 110v DC power supply to create a system of electricity for people. Meanwhile, Nikola Tesla invented the three-phase 240v Alternating Current (AC). Tesla was clearly a man ahead of his time (even by today's standards). tldr; Europe's grid is vastly superior to America's.

gattilorenz 3y ago
“The ability to directly plug most appliances without needing to buy extra adapters was amazing” unless you live in Italy, Switzerland, France (they have a socket with the ground sticking out I think), Poland, the UK, Denmark… it’s getting better and better due to the use of DC and the reduced need for grounding, though
mixmastamyk 3y ago
There’s a special plug for the oven, no adapter needed.

consp 3y ago

It's not all that weird though. Until the 1970's we had (in NL) 127 in some and 220v in other places which could either be 127v to ground, 220v to ground or 220v line-to-line. By around mid 2000's everything was switched to 230/400v for standardization in Europe, so it's not that long ago we still had some lower voltages.

rinron 3y ago

Here is a really great video that goes over the history https://www.youtube.com/watch?v=7yRGvMgieEU https://www.youtube.com/watch?v=7yRGvMgieEU Sometimes we think about the technical reasons and forget of the human and the developmental process that can sometimes have an effect on how things are today. spoiler for the video - its because too many 110v light bulbs were already in place by the time 220v ones were made and it was too expensive/difficult to change. kind of reminds me of why the US never switched to metric.

rootusrootus 3y ago
> why the US never switched to metric Pretty much exactly why the UK didn't. What, you say? The UK uses metric, right? Yes, in much the same way as the US does. Officially, the US gov't stance is metric. And in technical areas as well as much of the consumer space, metric is everywhere. What isn't really changing is layperson preference for units. People are comfortable with feet, yards, miles, Fahrenheit, etc. Just like the UK still using miles, and many normal people measuring weight in stones. Inertia is a pretty important consideration, and not invalid. Imagine trying to convince the UK to drive on the correct side of the road at this point. ;-)

throw0101b 3y ago

Kathy Loves Physics & History did a video on this, and the reason is basically legacy: * https://www.youtube.com/watch?v=7yRGvMgieEU https://www.youtube.com/watch?v=7yRGvMgieEU Edison originally purchased others' dynamos, especially Wallace-Farmer, which was 110V (DC): * https://americanhistory.si.edu/collections/search/object/nmah_705221 https://americanhistory.si.edu/collections/search/object/nma... * https://en.wikipedia.org/wiki/Moses_G._Farmer https://en.wikipedia.org/wiki/Moses_G._Farmer So Edison's long-legged Mary-Ann was also 110V: * https://www.collectorsweekly.com/stories/82967-thomas-edison-dynamo-long-legged-mary-a https://www.collectorsweekly.com/stories/82967-thomas-edison... * https://edison.rutgers.edu/life-of-edison/inventions?view=article&id=530:electric-generator&catid=91 https://edison.rutgers.edu/life-of-edison/inventions?view=ar... * https://americanhistory.si.edu/collections/search/object/nmah_1287625 https://americanhistory.si.edu/collections/search/object/nma... Light bulbs in the early 1900s were first designed for lower voltages, and the grid slowly raised things over time, but at some point they couldn't go any higher because it would start blowing things, so they were 'stuck' in the 110-120V range.

vonwoodson 3y ago

Because, Freedom. And, because America. **=== Now, I'm going to go talk to My Fellow 'Mericans about continuing to not use the metric system.

otherme123 3y ago
I am european. Regarding to the metric system, IMO americans are wrong. But regarding to electricity, americans have it better than Europe: France, UK, Italy, Switzerland, Denmark and Germany have their own sockets, and that after a recent spread of the german Schuko. We shouldn't lecture americans about changing things to use a standard.
- vonwoodson 3y ago
  There's nothing "wrong" about being The Best! #FREEDOM #TheseColorsDontRun #Merica

bloomingeek 3y ago

"In some rare situations 220V might be more dangerous to touch." Uh huh, here's an idea, go ahead and test that out for yourself!

Faaak 3y ago
And with 30mA GFCIs, the risk is greatly diminished

1970-01-01 3y ago

>Why do they use different frequencies like 50Hz, 60Hz? I've never found a technical answer for the 50Hz vs 60Hz question. It does seem to be an arbitrary standard.

michaelrpeskin 3y ago
My guess: in the old days when electricity was new, power conversion was done with Rotary converters which were basically a fused motor-generator. To change voltage you had different winding and number of poles. So if you were at 60 Hz, you have the magic of being divisible by a lot of numbers and you could easily go up down by common integer values. Then when Europe was standardizing, they wanted to be all metric, and 50 was close enough to 60 and still could become 100 by doubling. I don't know, those are just pure guesses. I think when you come from the engineering/tinkering side of things, you like units with easy integer fractions (12 inches in a foot is really easy to work with at human scale). When you come from the science side of things, you like easy decimals and that's why metric wins there.

tomohawk 3y ago

In the US, you can have electric receptacles in bathrooms. In fact, code requires it. You can plug in 120V electronics and appliances no big deal. In the UK, this is not allowed because 240V is not a good idea in bathrooms.

kypro 3y ago
Most bathrooms in UK hotels will have two pin 115v & 230v outlets for shavers. You can get them installed in homes too I believe, but most residential properties don't have them. They really are just for shavers though. You can't run anything high power without blowing the fuse. I believe Americans often use hairdryers in bathrooms. We definitely can't do that. That said, we do have electric showers in UK bathrooms but legally those need to have a kill switch installed.
tzs 3y ago
But it is allowed in most of the rest of Europe. I believe they do require those to have GFCI (as does the US since 1975). Does the UK disallow them even with GFCI?

hot_gril 3y ago

Every comment in this thread is mentioning a different angle of advantage/disadvantage between the two. I've given up on determining the winner, but that's ok, I'm just learning a lot about home power distribution.

mrguyorama 3y ago
There is no winner. It's a simple API, with many correct answers. The US ossified on it's system, and different European countries did the same. It's just a standard "Emacs vs VIM" flamewar.
- rootusrootus 3y ago
  > The US ossified on it's system Though it is crass, I'll say it. A silver lining to the tremendous infrastructure damage caused by world wars in Europe is that ossification was interrupted.
- hot_gril 3y ago
  Well if you compare it to emacs vs vim, that's making me think there is a correct answer.
  - bluGill 3y ago
    There is, but you are wrong... Hang on, let me go find my old flame war cheat sheet I need to throw a few more insults at you. /s
rootusrootus 3y ago
> I've given up on determining the winner That's because there is no winner. Nobody is doing something in the US that is impossible in Europe, or vice versa. There are upsides to both approaches, and different trade-offs, but everyone is getting enough power.
darknavi 3y ago
Tom Scott has a fun video not on voltage but on the merits of the wall sockets them selves: https://www.youtube.com/watch?v=UEfP1OKKz_Q https://www.youtube.com/watch?v=UEfP1OKKz_Q

codedokode 3y ago

I would like the voltage to be lowered even more, to 70 Volts. The reason is that 240V is very dangerous and can easily kill a human. But it seems governments care only about saving aluminium in wires rather than lives.

mcpackieh 3y ago
> But it seems governments care only about saving aluminium in wires rather than lives. That's needlessly inflammatory. Both the US and UK governments have numerous electrical standards and regulations designed to keep people safe despite unsafe power levels in residential wiring. You might argue that they aren't doing enough in this regard, but to say they only care about saving metal just isn't true.
mdekkers 3y ago
Death by electrocution is incredibly rare in the EU, what are you talking about? Data, or hold your peace.
- codedokode 3y ago
  Here is a recent case, for example [1] [1] https://www.dailymail.co.uk/news/article-12042495/Italian-girl-16-electrocuted-death-bath-phone-friend.html https://www.dailymail.co.uk/news/article-12042495/Italian-gi...
vel0city 3y ago
> But it seems governments care only about saving aluminium in wires rather than lives. I go even further on trying to save aluminum in my wires by not using any aluminum wires. Aluminum wiring is pretty rare in the US and largely considered a nightmare to work with.
- rootusrootus 3y ago
  > Aluminum wiring is pretty rare in the US and largely considered a nightmare to work with. Yeah, you basically only find aluminum wiring used today for the feeder, and for circuits larger than 60A. And that's mainly due to cost, copper is pretty expensive.

perfectstorm 3y ago

i wish 240V was more common. i can't charge my EV at a reasonable rate and it would cost me $15k+ to install a 240V in my detached garage (requires trenching).

tzs 3y ago
Could you do the trenching yourself? I don't know where you are, but in the US a walk-behind trencher rents for under $500 per day [1] [2] [3] [4]. [1] https://www.sunbeltrentals.com/equipment-rental/earth-moving/trenchers/walk-behind-trenchers/ https://www.sunbeltrentals.com/equipment-rental/earth-moving... [2] https://www.compactpowerrents.com/rental-equipment/trencher/24-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/... [3] https://www.compactpowerrents.com/rental-equipment/trencher/36-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/... [4] https://www.compactpowerrents.com/rental-equipment/trencher/48-trencher/ https://www.compactpowerrents.com/rental-equipment/trencher/...
deleted 3y ago
[deleted]
Anon_Forever 3y ago
>i wish 240V was more common More common where? Your main service panel is 240V. Do you only have a single 120V circuit feeding your garage?

jahnu 3y ago

Even stranger than that, Japan has two grids, one at 50Hz and one at 60Hz!

askvictor 3y ago
...which were completely isolated, until Fukushima led to power shortages so they hurriedly linked /are linking the two with DC interconnects.

kelnos 3y ago

I found it somewhat funny that the question included: >Explain me with calculation. As with many things related to technology, decisions are very often made for seemingly arbitrary (or political, or economic, or competitive-advantage) reasons, not because of some calculation that was done that proved a decision optimal.

hooch 3y ago

How does ChatGPT come anywhere close in usefulness compared to the breadth and fan-out of facts, opinion, supports and counter-arguments offered by this format?

sleepybrett 3y ago

similar story to railroad gauges

temporallobe 3y ago

I’ve lived in UK, Europe, and the US and I don’t really see a problem with either system. The 120V system is perfectly sufficient for most cases, even refrigerators and other large appliances. I suppose the one advantage a 220V system has is that you can put a stove or dryer anywhere, and you can run certain appliances, such as steamers and irons with way more power. On the other hand I find the UK’s plugs to be comically large compared to the US’s petite counterparts. Some European houses even have a few 3-phase 380V outlets for heavy duty equipment, which would be exceedingly rare in the US.

rekoil 3y ago
> Some European houses even have a few 3-phase 380V outlets for heavy duty equipment, which would be exceedingly rare in the US. My European 50m² apartment has two.

dim13 3y ago

Old joke: why USA use 110V and UdSSR 220V? Answer: because half of it will be stollen in transition anyway.

ralferoo 3y ago

The world is pretty standardised into these two now, but that can't always have been the case. In the early 1980s, my dad found an old valve keyboard / organ thing at some jumble or car-boot sale that probably dated at least from the 1950s, and being curious I used to regularly take it to bits. One thing that was weird is that there was an input voltage selector on it, but it was a round thing with contacts arranged in a circle and a plug that would bridge one contact to the centre contact. The range of input voltages was 60VAC to 240VAC, and there were probably 10 or 12 different voltages in that range. Unfortunately, this was also how I destroyed the keyboard part (but not the separate valve amplifier that I continued to use for at least another decade) because the 60VAC was next to the 240VAC and I accidentally bridged it to 60VAC and fed it 240VAC. All the valves were powered at 4x what they should have been and there was a bang and nothing worked after that. In retrospect, I should probably have kept it as probably only a few valves took the brunt of power surge, but even then valves were hard to get hold of and these weren't all the same (my memory is fuzzy, but there were probably 30+ valves in the keyboard, I only pulled a few to look at them and they were obviously different), so we just decided it was something that didn't need to be repaired. But anyway, long story aside - there must have been some demand for such a wide range of input voltages for the power supply, or they wouldn't have come up with a selector switch with so many possible options.

ralferoo 3y ago

Oh, another fun fact... Historically, the UK was 240V and Europe was 220V. This was later standardised across Europe as nominal 230V +- 10%, and AFAIK both UK and mainland Europe carried on as they were without actually changing anything!

stikypad 3y ago

220 VAC allows higher gauge (thinner) wires for the same wattage consumption and more watts per circuit for the same amperage (more powerful appliances and/or more concurrent appliances without tripping a breaker). And the UK in particular has far safer plugs than the US, with a fuse in every plug, partially insulated plug leads, and blocking shutters on the sockets. So basically we could use less copper, have safer homes, and simplify power supply design since we (and a handful of other holdouts) are basically the only countries using 100-120 VAC rather than 210-230 VAC, which would lower costs and reduce waste.