Introduction
This article is about a strange fascination of mine - when you travel around the world one of the first problems you encounter are the different shapes of the power outlets ๐. A question occured to me - do the various designs offer any advantage over others? Can we ask the question, which countries have the best plugs and power socket designs? Why do countries have various power outlets and why is so hard to standardise them โก? This article is my perspective on this matter and our journey starts in the United Kingdom ๐ฌ๐ง.
The brilliant engineering of the British Plug
My journey started with a video by Tom Scott:
The plug used in the UK is the type-G plug - it is easily the most bulky of the plugs used around the world, but with an superb design!
The plug has three pin, where the earth pin is longer than the other two - the reason for this is that all British sockets have built-in shutters, which only open when the earth pin gets inserted. It’s really strange that shutters are not more widespread around the world, because they can save countless children lives. The live and neutral pins are additionally protected with a small plastic protective cover, so the user cannot touch the live pins while plugging the plug in.
Even low-power devices with good insulation (like phone chargers) which do not need a earth pin have a plastic earth pin in order to unlock the shutters. I know what you might be thinking right now - let’s suppose you have a type-C plug from continental Europe, could you insert it in a British plug, assuming you have a screwdriver?
The answer is absolutely! But should you do it? The answer is no (and especially no if you use a Schuko plug - since the earth pins would be left floating). The reason for this is that the UK uses ring circuits, instead of radial circuits. The UK (and other countries which use the type-G standard like Ireland, Kenya and Malaysia) are the only ones using such a circuit design - the original motivation behind it was that ring circuits could save on copper - which was an issue after world war 2.
Ring circuits form a continuous loop, starting and ending at a consumer unit - the outlets are all connected to the same ring, enabling a more even distribution of power. Radial circuits, as used in the rest of the world are designed modularly - each (or sometimes several) outlets are connected directly to the consumer unit, however the circuits use a 32A circuit breaker and this is a problem for plugs rated at 3A, 13A or 16A, since if there is a fault, the breaker will not trip until the current exceeded 32A, sufficient to cause damage to the cable. So how do British plugs solve this issue?
The answer is by incorporating a fuse into the plug itself. In the UK each plug gets sold with its own fuse (typically with 3A, 5A or 13A ratings depending on the device and cable) - so if anything goes wrong, the fuse will blow before any damage can be done (these are very cheap and can easily be changed by the users). Other plugs do not have a fuse and hence you should not plug in a European plug in the UK.
Last but not least, the wiring inside the British plug is very cleverly designed - the wire connecting the earth pin with the cable is always longer than wires connected to the live and neutral pins - so just in case the cable were to be somehow pulled out of the plug, the live and neutral wires would detach first and earth last, preventing any dangerous situation.
Without a question, the British plug has a brilliant design and is incredibly safe!
The drawbacks of the British plug
The British plug of course also has some drawbacks, the most obvious ones are the very large size and the fact that the plug tends to fall down on its back - so people will almost always step on the pins. But British outlets also have some issues which arise from using ring ciricuits:
Since a fault in the ring circuit does not disconnect the electricity of an outlet (as one end would still be connected) it is harder to test a circuit for faults.
Ideally, the ring circuit acts like two radial circuits proceeding in opposite directions around the ring, the dividing point between them dependent on the distribution of load in the ring. If the load is evenly split across the two directions, the current in each direction is half of the total, allowing the use of wire with half the total current-carrying capacity. In practice, the load does not always split evenly, so thicker wire is used; and this is a problem, because ring circuits do not really save all that much wire for the same capacity.
Ring circuits are actually slowly falling out of favour in the UK, especially for higher power device outlets.
I also thought a lot about the fuse, but couldn’t the fuse be moved into the socket, allowing the plug to be smaller? Turns out that’s exactly the case with radial circuits. The breaker in a radial circuit is equivalent to the fuse in the plug, thus allowing the plug to be smaller.
Though I might be a bit critical of ring circuits, I still think that the British plug is superb and a great benchmark for comparing other plugs and sockets around the world. Speaking of the world, let’s cross the pond over to the United States ๐บ๐ธ. But before we do that let’s address the question why the world doesn’t have a single outlet standard
Why doesn’t the world use the same outlet type?
A lot of things across the world are standardised - nearly all nations use the same numerals, the metric system and the same calendar - but what some of the reasons why creating a common standard is so hard?
Frequency
For starters different electrical grids have different alternating current frequencies. North and Central America, Brazil, South Korea, Taiwan and Japan use 60 Hz mains, whereas the rest of the world uses 50 Hz mains. For a lot of devices a slightly different frequency doesn’t present a problem, but there are some that are sensitive to it.
Perhaps worth noting, old analogue encoding systems were very dependent on the frequency of the electrical grid. NTSC was used in the 60 Hz nations and PAL and SECAM in the 50 Hz nations - Brazil interestingly used a 60Hz PAL system. This is also the reason why videogames have NTSC and PAL regions, even though these systems have largely fallen out of use.
Interestingly, it is useful to know which sampling rate to use (multiples of 25 or 30 Hz) in video recording, because it can prevent flickering in your video if you sync your frequency with the frequency of the lights (which use the AC frequency)
Voltage
The far more pressing problem however is voltage. There are largely two kinds of countries, those whose mains have around 110/120 V and those whose mains are around 230/240 V. This is a big problem however, because plugging a 110/120 V device into a 230/240 V outlet, will destroy the device (blow its internal protection fuse).
Why do some nations use 110/120 V and others 230/240 V? Well mainly because the US was first to introduce a modern electrical grid and using lower voltages at that time made more sense (especially as the cables were not as strong), but as time passed on wires could carry greater voltages and the demand for higher power devices increased, which is why Europe (and later the rest of the world) adopted 230/240 V.
But even the US nowadays uses 240 V in homes (especially for higher power devices), but it splits the 240 V with a neutral wire in the middle to 120 V and -120 V. This does have the benefit of being safer, as the shocks only give half the current compared to shocks in the rest of the world, however the maximum power that can be drawn from the outlets before the breaker pops is of course smaller. But even in places like Europe, there are 400 V (and up to 1000 V) and up to 800 A and 500 Hz plugs, especially used in the industry, but also for high power applications like powering a mobile home - the best example being the international CEE 17.
Home circuitry
As already discussed most countries use radial circuits, while a handful use ring circuits.
So in conclusion, it’s really hard to standardise outlets, not only because we’d all need to change our sockets and plugs, but also because the very energy grip would have to be adapted to a common standard and that is not very economical.
Sockets around the world
Type-A and Type-B outlets
In the US ๐บ๐ธ, Canada ๐จ๐ฆ, Mexico ๐ฒ๐ฝ, Japan ๐ฏ๐ต and central America most plugs and sockets are of types A and B (the difference is in the Earth pin - type B has it unlike type A). These are some of the oldest outlet and plug designs - they were patented already in 1904 by Harvey Hubbel - in fact type A power outlets (those without Earth) are not installed in new buildings in the US and Canada anymore. Their main advantage is their super compact size (so much so that I will take the Type A and B cables as a size benchmark), however the plugs are sadly probably the least safe. The outlets are not inset and the pins have no protective covers, meaning that a half-inserted plug can still shock the user.
The plugs are rated at 15A and are typically used with 110 or 120 V and 60Hz AC electricity. Also here is an interesting video explaining why the plugs have two holes:
Type-C outlets (Europlugs)
The type C plug is best known around the world as the Europlug ๐ช๐บ, it is an unearthed two-pin hexagonoid plug roughly the size of the American Type-A plug, but slightly broader and more flat. It is the most widespread plug in the world and is typically rated up to 3A - so it is mostly used for low-power appliances like phone chargers, shavers and the alike.
Unlike all the plugs presented thus far, all Europlugs are unpolarised (so the devices must have polarity protection) - which means that you’re free to turn the plug around however you want - making the plug also very practical, especially if the cable is designed to go perpendicular to the pins - the Europlug presents a great benchmark for usability.
There is also a 10/16A version of the plug that is used for higher-power applicances which do not need Earth protection, though I feel a bit uneasy about higher-power appliances being unearthed.
A neat feature of these plugs is that they don’t have their own outlets - type C plugs are always used with other outlet types that are compatible with it, like types E,F and J.
Type-F (Schuko) outlets
A very popular plug type is also the German-based ๐ฉ๐ช Type-F Schuko-plug (Schuko stands for Schutzkontakt). It is also among the oldest plugs in the world - the Earth clips are on the side and yes just like the type C plug, the Schuko plug can be turned around at will, which is incredibly useful given that sometimes you just want your cable to go somewhere else, especially if the socket is behind some furniture.
All Schukos are rated at 16A thus allowing them power high-power appliances like washing machines.
Type-F outlets also have two very neat features:
- The sockets are inset, meaning that you cannot touch the pins, because you physically need to push the plug into the opening, blocking any space for fingers - this also provides the benefit that the plug sits in the socket mechanically and cannot be twisted or easily pulled out, except in one direction.
- The sockets which use shutters (and it’s a shame they are not widespread) will only let the plug in, when both pins get pushed through - this is a really cool feature as it prevents children from sticking needles or the alike into the plugs.
German ๐ฉ๐ช engineering is truly brilliant and doesn’t get enough credit. The biggest drawback of the plug however is its size - it’s not as big as the British plug, but still quite massive, probably to have a circular shape - but I think that this is somewhat redundant.
Plugs similar to Type-F (Type-E, Type-H, Type-K, Type-O)
The Type-E plug is used in countries like France ๐ซ๐ท, Belgium ๐ง๐ช, Tunisia ๐น๐ณ, Poland ๐ต๐ฑ and the Czech Republic ๐จ๐ฟ (and some old outlets in Switzerland ๐จ๐ญ used it), it differs from the Type-F plug in that the socket has a Earth pin - this is very unique among the world standards. What is worth noting about the plug is that most European plugs are compatible with both type-E and type-F sockets - that’s the reason why even in Germany the Schuko has a hole in it.
The Type-H plug is used in Israel ๐ฎ๐ฑ and the sockets are also compatible with Europlugs. Curiously Israel changed the shape of the plugs from a design reminiscent of the Australian Type-I looking shape to a more round shape.
The Type-K plug is used in Denmark ๐ฉ๐ฐ and Greenland - the socket makes a sympathic happy face.
The Type-O plug is used only in Thailand ๐น๐ญ and has the same dimensions as the type E/F-plugs (which is why they can be used there, but shouldn’t because the ground pins can’t connect to the hole) but the socket is not inset and the pins have protective covers.
The old British standard (Type-D and Type-M)
India ๐ฎ๐ณ and South Africa ๐ฟ๐ฆ use the Type-D and Type-M plugs. Shape and size-wise they are very similar to the British plug, except that the pins are round. The Indian plug is smaller and rated at only 6 A, while the South African plug is enormous and rated at 16 A.
You can still find these outlets in really old British buildings that survived the war. I think that these two plugs easily have the most disadvantages, they are very big when compared to the Type-A plug, have the least safety features, especially when compared to the British plug, and also don’t offer the usefulness of the Europlug.
Type-I
This type of plug and sockets is used in an interesting combination of countries - Australia ๐ฆ๐บ, New Zealand ๐ฆ๐บ, Argentina ๐ฆ๐ท and China ๐จ๐ณ. It is essentially a mix of the old British plug and the round design of the type F-like plugs. It is rated for 10A and 15A and is a surprisingly small plug, smaller than the Schuko and slightly but not much bigger than the American plug - fun fact, this plug was designed by the same person that designed the type-A plug, but it never took off in the US.
Plugs in Italy and Chile (Type-L)
The type-L outlet is the most chaotic outlet in the world, it is used in Italy ๐ฎ๐น, Uruguay ๐บ๐พ and Chile ๐จ๐ฑ. Design-wise it is a Europlug, but with an extra earth pin between the two - it’s actually a very logical design - but there are two versions of the plug the 10A and 16A versions and they have different sizes including the spacing between the pins and the pin width itself.
The problem is that the 16A Type-L outlet is not compatible with 10A Type-L plugs and vice versa - and since Schuko plugs are very widespread in Europe, Italy often uses bipasso sockets which support all three socket types. I feel like the Italian plug has a good design on paper, but a weak execution.
Type-J
Now we come to one of my favourite plugs, the Swiss ๐จ๐ญ type-J plug. The plug is a larger version of the Europlug (which is compatible with Swiss outlets) but it has an extra Earth pin. The plug is rated at 10 A and has all the neat features of the British plug, except of course for the fuse (but in a radial circuit, the fuse is effectively replaced by the breaker in the consumer unit), but with inset outlets, which provides a very strong mechanical grip and additional safety against shocks.
What I find really neat about the sockets is that since they are so small, that three sockets can be placed on one outlet, whereas only a single socket would fit in the UK and EU and two in the US.
Why Type-N is my favourite socket type
And now we come to the international type-N plug, my favourite plug and socket design (and not only because I love international things ๐๐).
It was designed in Europe ๐ช๐บ and was meant to replace all other outlets for 240V nations and make sure that the EU nations would all harmonise their plugs and sockets. Sadly this adoption never took off in Europe. However this didn’t stop South Africa ๐ฟ๐ฆ and Brazil ๐ง๐ท from adopting this plug as their own (though note that most of Brazil is using 220V 60Hz and in some states the plug is used with 110V 60Hz rated at 10A and 20A, thus deviating a bit from the standard).
The plug is almost identical to the Swiss plug, except that the Earth pin is closer to the line connecting the live and neutral pins, making the plug smaller and of the size of the Europlug. This makes this it even thinner than the American type-B plug and even though its pins are slightly thinner than those of the Schuko, the plug is rated at 16 A - making it even more powerful than the Swiss plug. It has all the safety features of the British plug (except for the fuse, which is now moved to the consumer unit), it always falls on its sides, preventing people from stepping on the pins and has inset sockets preventing any electrical shocks and providing a strong mechanical grip. Type-N outlets support the Europlug and just like with the Schuko the shutters to the outlet can only be opened, if a plug is inserted through both the live and neutral pins at the same time.
Thanks to modern injection moulding technology, which did not exist when most other plug types were originally designed, the very recent type N standard is more compact, robust and safe than any other plug/socket system in the world and it is thus my favourite design.
South Africa recently replaced its old dangerous and huge Type-M plugs and I think they made a very good decision, if you’re interested in even more arguments in favour of the international outlets, I can really recommend this video (it also discusses British, Indian and German plugs):
Conclusion
There are a lot of differences between electrical distributions around the world, especially when it comes to voltages and radial/ring circuits, so its unlikely the world will ever agree on a single outlet, so travelling adapters are likely to stay.
But with that said there are a lot of interesting safety and usability features incorporated into some of the plugs and sockets - I think it’s hard to say which plug is best, but I really love the types F ๐ฉ๐ช๐ช๐บ, G ๐ฌ๐ง, J ๐จ๐ญ and N ๐ฟ๐ฆ๐ง๐ท plugs and sockets with the international type-N being my favourite โฅ๏ธ๐๐.