Every US Electrical Outlet Explained [video]
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That and switches (like light switches): not only we've got way more variety in the EU but they also all feel of better quality.
Both electrical outlets and switches in the US do also look old and dated. Just like they feel when using them: old and outdated.
It's just all really weird, nearly anachronistic.
So, when I arrived in Barcelona and Catalonia, I was pleasantly, mildly surprised that not only had Europe kept pace with us techno-mages in America, but they had some kind of parallel evolution going on, in terms of connectors, interfaces, protocols, etc.
My fiancée was sort of mystified, because my favorite subject of photography was not landmarks or her pretty face, but the circuit breaker box, the rear of her television set, the A/C unit, and any other cool, distinctly Euro-tech instances I could identify around there.
I tried helping her adjust/fix her aerial TV antenna, got zapped a few times; discovered that Catalonian TV antennas are energized with a few volts for whatever reason; decided that Euro-tech is beyond my expertise to tinker with on someone else's behalf, especially a native family.
Thankfully, I didn't have any portable electronics or appliances in my luggage that needed adapters or plugs, but the experience was truly humbling, and eye-opening, and I returned to the United States with a better calibrated worldview.
Competitively the US does well in energy tech and agriculture tech. The US is #2 in wind power, #2 in solar power, #1 in nuclear power, along with being the world's biggest oil & natural gas producer. The US industrial rail system is also an epic scale marvel, while its consumer rail system is pathetic.
It's definitely not elite in most infrastructure (including electrical plugs).
If you were than combined figures put USA behind places like Germany and Spain.
And bringing nuclear into it you get France absolutely trouncing.
So your argument is that “america is a big country”.
Meanwhile Europe standardized bank transfers with IBAN, killed connector type proliferation with by standardizing on USB-C, and routed 3-phase power most homes. Oh, and the metric system. And while Europe has a wide range of cultures and functionality of government, a lot of places have simpler tax forms and a more prescriptive legal system (as opposed to the precedent-dominated Common Law tradition in the US). The German-speaking countries even rewrote spelling to make it simpler.
I view a lot of this stuff as infrastructure investment. We shouldn't have to stumble over the mundane to do interesting things. As others have commented, Europe also had the advantage of adopting some technologies later, but in some cases they just seem to be more aligned with a system of constant (if sometimes frustratingly slow) improvement.
What is the advantage to this? Are there use cases for using all three phases (in one appliance?)?
The difference between one three-phase feeder and three completely separate two-wire circuits is that the three phases, which are 120° apart, share a single neutral conductor. In fact, if the load is perfectly balanced across the phases and currents are sine waves, they will cancel each other out, so neutral will carry no current at all and can be omitted! But in practice, there still usually is a neutral conductor to carry the imbalance (except for specific loads like delta and star motors under certain conditions). In total, we only need 4 wires instead of 6 to carry the same amount of power. That's 1/3 less copper! (Excluding PE of course.)
Now, compared to using a single two-wire circuit rated for three times the current, three-phase also wins by a long shot. (We're again assuming a balanced load and equal power factors.) This is because resistive heat scales with the current squared, so 3 times the current produces 9 times the amount of heat at the same resistance. So, we need to use thicker conductors to lower the resistance. But the area of its cross-section grows quicker than the surface area to dissipate heat, so the maximum current a conductor can safely carry scales sublinearly with its cross-sectional area. For example, 1.5mm² will suffice under most conditions to carry 16A, but for 48A we'll typically need 10mm².
All in all, the rule of thumb is that three-phase AC gets you the same amount of power for roughly 25% less copper compared to single-phase AC!
Some loads also make use of the rotating magnetic field, like motors (see below).
Lastly, lower currents will reduce heating in case of loose connections, reducing the risk of fire. On the other hand, a 400V RMS phase-to-phase shock is a lot more severe than a 230V RMS phase-to-neutral (or phase-to-PE) shock.
Common use cases (load-side):
- Motors. Three phases produce a rotating magnetic field, perfect for simple self-starting motors. (Arguably, this is less relevant today with more modern motor designs, though three-phase induction motors are still widely used.)
- Electric cookers (usually split by cooking zones and oven, like one phase for two zones each, and the third phase for the oven)
- Water heaters (especially those that heat water instantaneously on demand)
- EV charging (even an ancient European three-phase installation is likely able to deliver 11kW of power and can therefore fully charge an EV overnight)
That might because the US was largely electrified by 1950 with the major push before The War during the 1930's via the Rural Electrification Administration. By The War the TVA was up and running and that's where nuclear materials were manufactured for The Bomb.
The US system sensibly uses 110-120V for most uses and then 240V where it really matters.
And... the plug really isn't that big at all.
E.g. [1] is a "Max 10A" power strip, so the cable would heat and potentially melt if a 15-16A load is connected.
[1] https://www.silvan.dk/produkt/stikdaase-m-ledning-4-udtag-u_...
But in France, the 16A shuko outlets are on a max 20A breaker, which means you can still overload a 16A power strip, but I guess there's enough margin there that the regulator considers that to be OK.
Although at least at my work we had someone come in and replace all the power strips with ones that have a 16A resettable breaker thing built in. So maybe I'm commercial spaces it's different.
Here's the larger one: https://www.bauhaus.dk/stikdase-u-jord-4r-10a-5-m-hvid
With an earth: (Danish plug) https://www.bauhaus.dk/stikdase-m-jord-3r-10a-5-m-hvid
IIRC, the US electrified first. So a lot of its standards are kinda the first attempt, but they've stuck because the switching costs are too great. Other countries had the benefit of being able to improve on an existing system.
But I'm not sure if that really applies to plugs (IIRC British [giant] and Japanese [no grounding] ones are worse). But my understanding is the US 110v thing is kinda limiting, and 220v is way better.
> Plugs don't fit properly: they simply feel loose.
Let me guess: it was in a hotel? Hotel plugs are shit and worn out, because they get used far more heavily than pretty much anywhere else.
> Or you need to use super bulky, non-sensical, plugs.
For what? The only bulky US plugs are for weird things like dryers and electric ovens.
120V is safer (not "safe", "safer"[1]) than 240V. And for the times when 240V (or 208V) is a better fit, we have that available to us relatively easily.
> For what? The only bulky US plugs are for weird things like dryers and electric ovens.
Or the locking plugs, but I think that still fits your point: These are high-voltage and/or high-current things, which aren't being unplugged/plugged too much.
But those are the situations where we then use 3-phase 400V
> Curious why you’d need/want whole home gfi
Because the danger they protect against is not confined to bathrooms and the outdoors!
An RCD (GFCI) trips quickly when there is an imbalance between outgoing and returning current exceeding a certain threshold, indicating that some current is likely leaking to earth. A little more than 30mA AC through the body sustained for a couple of seconds can kill someone, but is not enough to trip a regular circuit breaker!
Wetness increases conductivity and therefore the risk of a dangerous electric shock, but a faulty appliance or damaged cable elsewhere exposing you to mains voltage can be life-threatening too!
So, why shouldn't we protect the entire house?
> I'm assuming [...] if there’s a short on any circuit power to the entire house is cut
Small nitpick: a GFCI/RCD doesn't trip because of a line-to-neutral short circuit, it only trips if some current "escapes" to somewhere else. Though it is true that nowadays we often install RCBOs which combine residual-current, overload, and short-circuit protection.
But your concern about nuisance trips is somewhat justified. If there is really only one RCD serving the entire house, which is very common for older installations, a ground fault will cause a larger outage.
Newer installations, however, typically use multiple RCBOs to reduce the blast radius. And really old installations, where small current leaks are more common, might not have an RCD anyway.
Also, in my experience, it's just not a problem in practice. I can count the number of nuisance RCD trips I've had in my life on one hand. And genuine faults are similarly rare. Other kinds of power outages are far more common.
> GFI outlets provide a very localized layer of safety [...] can be extraordinarily sensitive
I fully agree that this is an advantage.
A standard 30mA RCD or RCBO, as would be installed in Europe, should disconnect within 40ms at 150mA, but might take longer at lower currents. That could still be quite a substantial electrical shock. (I'm not qualified to say exactly how dangerous it still is, but I can attest to the fact that it can still hurt pretty bad even if the RCD trips.) A 5mA GFCI, as is typical in the US, provides a much larger safety margin. I guess nuisance trips would be a much bigger problem if the detection threshold for RCDs was lowered to 5mA.
So maybe we can agree that the perfect solution would be to have GFCI outlets everywhere? Because as it stands, you either have crude protection everywhere, or good protection limited to a few outlets.
One last note: Whether you have GFCI outlets or RCDs in your electrical panel, make sure to test them regularly via the test button! A faulty protection is no protection, and it's better to be safe than sorry.
Edit: One more thing worth keeping in mind is that, all else being equal, 230V drives almost twice the current as 120V, making the shock more dangerous and residual-current protection even more important.
Meh, gfci outlets aren’t that expensive so if you’re a super vigilant home owner you could easily put one on every circuit in your house. But modern code calls for them in the laundry room, garage, bathrooms and kitchen, so for all practical purposes you almost do have them on every circuit.
For the whole house or circuit, that’s exactly what breakers are for.
For the risk of shock from an electrified appliance, that’s what the ground is for and is a very reliable solution provided that it’s actually done correctly. Unfortunately a lot of builders and electricians cut corners and either don’t ground or don’t do it properly.
To me seems like people are hating on a pretty great system. Put differently, if all you had was a whole house GFCI and someone invented an outlet GFCI that enabled localized fault detection at very low levels it would seem like an advancement. Funny to hear people want to go backwards.
Ground does not protect against every shock hazard! Devices can fail in many ways where live parts are exposed without contacting the grounded casing. Also, imagine a little child poking a metal stick into the outlet. Now you'd better hope that outlet has GFCI. Modern code does not call for it in a child's bedroom, does it?
Edit: To be fair, modern receptacles should be tamper-resistant, but then imagine a child reaching into a lightbulb socket, or cutting through a wire, or the insulation on a wire becoming damaged, etc. pp.
> for all practical purposes you almost do have [GFCI] on every circuit
But there are still gaps! I got shocked by an old clothes iron once (and I'm glad it tripped the RCD at the panel). Bedrooms and living rooms can have electrical faults too!
Another advantage of RCD at the panel is that it protects all downstream parts of the panel and all circuit wiring too! A lot of fatalities come from people working on live wiring. (In fact, many electrocution deaths are electrical contractors.) Now sure, they almost certainly weren't following correct safety procedures, but still, a lot of them could have been saved by an RCD. Some people probably die changing their light bulbs. That's preventable by installing an RCD at the panel, so that the entire circuit is protected, not just everything plugged into a GFCI outlet.
> To me seems like people are hating on a pretty great system. [...] localized fault detection [...] would seem like an advancement
I agree that localized fault detection, all else being equal, is an advancement. But if it comes at the cost of no GFCI protection at all on other circuits, I'm not sure it's worth the tradeoff.
Hundreds of people in the US die every year from low voltage electrical shocks. This number used to be a lot higher before GFCI was common, but it likely could be lower still if GFCI was required everywhere.
Obviously it would be best to have broad coverage and localized tripping, but if I had to pick one, I'd choose broad coverage. Calling it "going backwards" misses the concern of how much is protected, rather than just how localized the impact is when there is a fault.
It trips whenever hot wire gets exposed and touched by anything other than return wire. So basicaly it protects against any failure of insulation of the hot wire. At the latest when you come in contact with it in any manner.
I'd call both the British and the Schuko better. But they both come with tradeoffs. The British plug is huge, in part because of the built-in fuse. The Schuko is aesthetically less clean because the outlet is not flush, and because the plug is reversible you can't design around polarity. Both excellent plugs that are huge improvements over the US plug design in most ways, but both come with their own tradeoffs
See also: https://plugsocketmuseum.nl/GB-foldingPlug1.html
My international travel "brick" for laptop + phone is an Anker PowerPort Atom III Slim, which is flat multi-port charger with an IEC-320-C8 input. For the Continent, I plug in a "0cm cable" that's a Europlug nub. For US and UK/I, a NEMA cord with a compact BS1363 "shaver adapter" with a 1A fuse in it. Really wish I could get something flatter to be the adapter! Maybe I'll have to make one.
I appreciate that they seem to put some effort into the design of their UK only products, instead of just shipping a US/Cn shaped charger with a BS1363 plug grafted on
I tried that once and the fit was so tight I thought I'd break both the plug and the outlet.
The look can be improved by using receding covers. I am sure they exist for Schuko outlets, here is one for a type E socket (CEE 7/5, usually compatible with Schuko AKA 7/3, using 7/7 plugs): https://www.domomat.com/53812-prise-de-courant-affleurante-o...
As a side note, the type E is polarized, though on occasion you can find modified 7/7 plugs that accept both orientations (I see this most commonly on PLC adapters). IEC 60906-1 was designed to replace Schuko but was not adopted.
Most people in the US will go their whole lives without having an issue related to this or knowing anyone who did. This is one of those problems that mostly only exists as a post-hoc justification for an already held belief.
Regardless, the typical outlet is not GFCI protected just due to the math of volume of new construction vs old construction vs service life. We're probably close to 50% coverage in new builds, more in low room count/wall area apartments. Tamper proof outlets are a better solution for this non-problem anyway.
> Yeah until you have kids. Before GFCI were a code requirement, electrical incidents were a constant source of injuries and fatalities.
Isn't GFCI only required in wet areas (e.g. kitchen and bathroom)? And even if they're not more widely required, code requirements aren't retroactive, so I'd imagine the vast majority of houses will be missing GFCI from a large number of outlets.
Austrian electrical code is even more strict, every time a renter changes or the home is sold, electrical wiring has to be brought fully up to current code.
More efficient with copper certainly, but 110V is safer: cf. Ohm's Law. Lower voltage penetrates skin less readily, so you're more likely to escape unscathed from a 110V zap.
In Ireland, on worksites, the corded tools are 110VAC/50Hz (115V, 120V... mains/2 on a transformer-- and 'mains' varies wildly according to my several years of data captures in a range between 214-240).
Speaking of copper efficiency, the British Isles do all kinds of silly things like running ring mains to enable the use of smaller conductors for higher loads on domestic electrical sockets, and notionally to provide a safety factor.
But in all seriousness they are comprehensively safer. The earthing and exposed live benefits are shared by most EU plugs, but as a bonus you've got:
- Built in fuse that can be sized to the appliance, not the socket
- Sliding gates on live and neutral that stop your 5 year old jamming a fork in there
- The gate is moved by the earth pin, ensuring it's long enough to make first contact
- An internal wiring arrangement that avoids floating the whole appliance at live if a cable is forcibly ripped out
Yes, it's a bit bigger but I can't recall this having caused even one dead child worth of inconvenience across my life.
They are however, even worse than Lego to step on in the night. I'll concede that as their one true weakness
It's nice that they're mandatory though.
Yes, that is the intended purpose of the fuse - To stop a faulty appliance drawing excessive current and starting a fire.
The benefit of the per appliance fuse is that a 3A appliance can have a 3A fuse, rather than the full 13A the socket is rated to provide. No difference for a dead short, but easily the difference between fire and no fire for a stalled motor.
Can I ask why you think a ring main is more likely to cause a fire if overloaded? I think this could be a misconception, but I'm curious to hear your thoughts
You can have 240V for any plug in the house in the US: install a double-pole breaker at one end, and a NEMA 6 plug at the other.
The US uses 240V in a number of situations: it's used for kitchen ranges, clothes dryers, external AC/HP units, and recent EV charging. Are there other places where it's needed? (Personally I wouldn't mind having it for tea kettles.)
But how many other applications need >2000W of power delivery that 220V would allow?
Tea kettles, space heaters, some power tools (e.g. I've got an electric power washer that uses like 14A, and it was too weak to run an attachment I'd hoped to use with it.).
Also, I think countries that have 220V at the wall have access to 440V for when Americans would use 240V, so they can have even faster EV chargers, etc.
Did anyone say Schuko?
Also, I have noticed that at the (very large) medical center where all my doctors are, all outlets are installed "upside-down". These are the regular outlets where things like PCs are plugged in, and is true both in new and in very old buildings. Anyone have any idea why they would do that?
When I rented a house, I went through and tested every outlet, light and switch and labeled them documenting their control and circuit. It seems like that should be standard for homes when they're built.
So, ground side up is usually safer.
I do not recall hearing a explanation of why the US naturally installs things to be more dangerous.
Our next data center, for the HPC portion, may end up getting 480 VAC to the rack, with each outlet getting 277 VAC (one phase plus neutral and ground). If you order a generic Dell server, you'll find they now have power supply options for 277VAC.
What's the outlet? The D-Grid 400 (SDG 400). So, there's another outlet to add to the list!
(Haven't had to look at the NEMA outlet chart in years. I once had to specify a computer room back when DEC was a company. DEC used about five different connectors - some 110V, some 220V, some 3-phase, various current ratings. Needed custom-fabricated raceways with all the correct outlets.
Plus the electrical people at the aerospace company insisted on putting a hulking big copper busbar tied to ground on top of each raceway, and all cabinets were grounded to that. That was to give RF noise a very low resistance path to ground. Much RF R&D took place in that building, and things which blithered all over the RF spectrum were seriously annoying to the RF engineers. Computer grounding used to be a big deal, before everybody started using differential signals for almost everything.)
The way those old outlets work is you get two hots and a ground. No neutral. This is fine for simple appliances that run wholly on 220v and utilize mechanical controls (so like all old appliances) but as you start adding complexity in the appliance you start wanting to use 120v control circuitry stuff (i.e. a cost saving hack by the device manufacturer) and this opens the door for the appliance to be live at 120v if the case is bonded to the ground and your ground wire in the cord is broken. Or it opens the door for the case of the appliance to be floating and live at 120v if there's a short to it.
With appliances manufactured for global markets these days that accept all manner of input voltages and run any controls off of some DC powered circuit board this isn't really a problem anymore but with the way people worship rules like religion I'm sure in the year 3026 we'll still be reading comments like yours.
Protective ground is never supposed to carry current unless there's a fault. The neutral in a 3-prong dryer plug is the return for the 120V motor, so it carries current.
I've had an open neutral on my house. A tree slowly grew enough to take out the drop to the house, and it broke the neutral first. The computers were fine but smoke came out of the washing machine, which saw overvoltage.
[1] https://epicelectrical.com/3-prong-vs-4-prong-dryer-outlet/
unrelated to 1st paragraph - I like as well Mustard, B1M, Wendover Productions