The design of Britain's wall sockets | Hacker News Reader

The design of Britain's wall sockets

fastcodesign.com

51 pointsrwmj65 comments

I don't see many advantages over the Schuko plug, used in most of Europe:

https://en.wikipedia.org/wiki/Schuko

The outlets are recessed, so you physically cannot touch any of the pins while they are engaged. For the same reason, ground is on the periphery of the plug and engages before the pins make contact. The Schuko plug and outlet are designed to prevent you from shocking yourself while still being a reasonable size and aesthetically pleasant. The safety shutters mentioned in the video are standard in Schuko outlets in some countries.

It's great that they thought about safety when standardizing the design, and interesting to see precisely which decisions were made and why. However, "Best On Earth" is a bit hyperbolic for a video that makes no mention of a more popular design that embodies all the same safety features (save for the in-plug fuse) in a more convenient form factor.

On the topic of the Schuko plug, I never really understood why there had to be that many variations of it. Being from Denmark, I have more often than not had problems with the ground pin obstructing me from using a Danish plug in other countries. It has often times lead me to either saw off the ground pin, or replace the plug with a two-pin connector without the ground pin - in both cases decreasing the security of the plug for accessibility.

There is no degenerate 2-pin variant of the UK plug to compromise the safety of unearthed devices.

The UK model is the most painful plug to stand on, due to it's propensity to lie 'prongs up' and the particular arrangement of said prongs.

This is a deliberate and oft misunderstood feature of this plug.

In the event of an invasion standing orders are for every British citizen to cut the plugs off their appliances and scatter them in the streets as makeshift caltrops, delaying the enemy advance and crippling any soldier unfortunate enough to have removed his shoes.

Sorry. It's just too big. Electrocutions and fires from plugs are not widespread in the US/Canada. The UK plug is a solution for a dead problem. There is no practical need to continue with plugs bigger than many of the devices they power.

Uk is 240V 13A which is a bit more powerful that the 110 v Us system.

Looking around my place, I don't see any devices that would care. Short of heat devices like kettles and dryers, everything can be run on 110v/15a. So if voltage is the only reason for keeping those brobdingnagian plugs, that too should be revisited.

In the USA, most wall circuits are 120v, 20 amp. Kettles, hair dryers, irons run fine on this, typically 1200-1500 watts each. Clothes dryers, which we are in love with, are a 240v, 30 amp dedicated circuit.

>> most wall circuits are 120v, 20 amp.

The circuits yes, but the outlets/plugs are generally 15a. There are many hospital/industrial grade plugs that are 20a non-continuous, but anything that requires a steady 20a will have a strange t-shaped plug you will never see in a residential setting. If you want 20a most go with twistlock plugs, which are standard in the film/tv/live entertainment industry.

The NEMA 5-20 receptacles are readily available at home improvement stores. To the extent you don't see them in residences, it's because the electricians were cheap. There's scant other reason to not use them on say a dedicated 20A bathroom circuit.

20A outlets are all over the place these days. I'd say they're more common than 15A in commercial settings, and they're not uncommon in houses either. My relatively new house has 20A outlets for all the GFI outlets, but 15A for the rest. Not sure why.

Note that circuit and plug capacity is always listed for non-continuous. That typical 20A wall circuit is only rated for 16A continuous, ditto the 20A outlets, and the standard 15A outlets are only good for 12A continuous.

I don't think kettles, hair dryers, or irons count as continuous draws, so this doesn't really matter unless you're plugging in your clothes dryer, oven, or car.

Kettles and hair dryers are typically 1200-1500 watts because that's all they can draw on a typical American circuit. A quick look at these items on amazon.co.uk shows that they have much more powerful stuff. Every British electric kettle I see there draws 3000W, so will boil water in half the time.

240V is not the reason. The continental Europe also has 240V and 16, 10 or 6A. All that with a sane plug size.

Higher voltage should actually make plugs smaller. Higher voltage means that you can deliver the same amount of power with less current. An American appliance which pulls 10A will only need to pull 5A in a European version. Conductor and plug size pretty much doesn't care about voltage, but scales with current drawn.

Voltage dictates size, just not during normal operation. [Don't do this] Turn on a toaster and turn off the lights. Then yank out the toaster's plug, fast, [Don't do this] as if you tripped over the cord. [Don't do this] You'll see a blue flash, two arcs from the plug to the outlet, possibly merging into a single arc between terminals. The last thing anyone needs is such an arc sustaining for more than a nanosecond, or across terminals in the outlet. Higher voltage plugs need larger distances between metal parts to prevent sustained arcs.

This why if you smell gas you shouldn't ever unplug anything.

That's very much a secondary effect at household voltage levels with typical equipment, though. A NEMA 6-15 outlet has no more separation between the blades than a 5-15, for example.

Look at American films and tv no one ever has a proper electric kettle - they use those ones with a whistle you put on the stove just like my gran did 50 years ago.

And if electric cars take off you will want to charge them on a cooker circuit

> Uk is 240V 13A which is a bit more powerful that the 110 v Us system.

Actually UK is 230V and North America is 120V.

https://en.wikipedia.org/wiki/Mains_electricity_by_country

UK is nominally 230V to standardise with the rest of Europe but actually 240V as it always was:

"Following voltage harmonisation, electricity supplies within the European Union are now nominally 230 V ±10% at 50 Hz.[6] For a transition period (1995–2008), countries that had previously used 220 V changed to a narrower asymmetric tolerance range of 230 V +6%/−10% and those (like the UK) that had previously used 240 V changed to 230 V +10%/−6%.[7] No change in voltage is required by either system as both 220 V and 240 V fall within the lower 230 V tolerance bands (230 V ±10%)."

https://en.wikipedia.org/wiki/Mains_electricity#Standardisat...

I don't know if 240V is actually being phased out now it's post-2008 but the mains of everywhere I've lived since 2008 has definitely still been 240V.

Survivor bias.

We once (edit: still do) had round-pin 15 amp plugs that were even larger.

But then at the same time we had smaller 5 amp plugs with 3 pins and even 2 amp plugs with 2 pins.

Then there were the Bakelite Y adaptors you could pop into lamp sockets in the ceiling to power a radio or similar low current device - they were used in houses that only had light circuits, no ring main. Those houses would have started with DC circuits, and would have had gutta-percha insulation on solid copper in the ceiling voids.

So that many decades ago, you could have 3 different plug standards in one house AND still see the jets and taps for gas lamps!

My point being: we might get away with a smaller plug, but the transition would take a few decades. The full story is below. I'd forgotten about the 30A 3-phase plugs...

https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets:_Br...

For what it's worth, Ireland, Hong Kong and Singapore also use this socket type (among others). As someone who grew up with these sockets and moved to the US, I have definitely found the British type to be far more robust. The sockets in my US apartment have terrible grip, with my laptop charger often sliding out, which certainly soundly happen with the British style.

Check the receptacles. They are probably worn. Replacing them with better quality ones will solve that problem. New construction uses cheap crap, GE, Leviton, Eagle typically. Pass & Seymour,Hubbell,Bryant are examples of premium brands.

Yes, but we Brits don't need receptacles. This this problem doesn't arise.

Land of hope and glory...

I went to East Africa for the first time in 2013 and was surprised to see British style plugs on Zanzibar. But how could it be otherwise, since electricity would have been installed under British rule in the first half of the 20th century...

It's a good subject, but the article neglects that the reason for the fuse is the rather high current "ring main" which was a copper-saving measure.

If you don't need the fuse in the plug, the Schuko plug is pretty nice too.

Honestly, as far as mains connectors go, I'm a huge fan of Schuko for two very big reasons:

There's no polarization, so you get away from that faux-safety reasoning behind "well, neutral should never be hooked up to a switch" nonsense with non-fixed equipment. This extends too to equipment with faulty designs, like toasters lacking double-pole switches. It should really go without saying that you should always unplug the device from the wall if you intend to service it.

In addition, Schuko separates the electrical connection from the mechanical connection. This has the obvious benefit that a failure in either won't become a safety concern. Readers from the US will likely understand why this is huge in the context of things like wall warts. (;

Exactly. The high current, if combined with unevenly split loads, improperly installed or maintained wiring, excessive use of spurs etc. can actually mean a greater risk of (fire) damage due to overload compared to 'star'-like circuits carrying less current per segment. https://en.wikipedia.org/wiki/Ring_circuit has some of the gory details.

The attached video explains the ring main.

Also, modern overhead lights in the eu switch with low voltage to the switch, further decreasing risk and copper use as a thinner gauge could be used.

It also seems like British wall sockets have switches on the wall itself. It seemed pervasive to me, but I don't know if that is a law, standard practise, or just luck.

However it is great because you can always turn something off at the wall, without having to remove the plug from the wall. I'm sure that repeated unplugging in situations without a wall switch cause more problems for electrical safety/wear and tear.

I love the integrated switch on the wall as a concept. I'd love to switch off my microwave between uses because its VFD and internal clock being constantly on makes little sense to me. This sort of draw would be an impediment to an off-grid or hybrid power system, constantly draining the supply.

Agree with everything in the article, but one downside: it really, really hurts to step on one. US plugs can't really ever end up with the prongs facing upwards when unplugged, whereas UK plugs are extremely likely to.

OP mentioned that in the very last word of the article.

https://en.wikipedia.org/wiki/Caltrop

British plugs have always reminded me of "Fisher-Price my first power socket". It's amazing to see for example, an iPhone lightning adapter, a design iterated upon to be ever smaller and sleeker, attached to this ham fisted plug on the other end.

I like extension cords that include both 230V and USB sockets, so you don't have to use power adapters for every device. Makes me wonder if electrical infrastructure could some day be updated to match modern usage patterns.

Here's an example picture, I'm sure these exist in all countries: http://www.airam.fi/fileadmin/tuotekuvat/vapaa-aika/2441532_...

Some friends with camper vans were recently discussing whether to get 240v for their respective vans. The guy at the garage wasn't recommending it because of a lack of a 'use case'.

I would like to see the UK ring main revisited to provide a useful USB power ring main where devices can negotiate current demands, e.g. to power a laptop without dropping the voltage for anything else plugged in to the 5v DC. How would a modern day government set a standard for that?

It isn't 1930 anymore. You can't use past electrical systems as an argument of why your nation has the best plug.

Aside from the fact that ring mains should probably be eliminated, and it's hard to trust cheap appliances to have properly safety-rated fuses in the plugs today, I don't see what else has changed.

The UK doesn't have safety laws? Or are you buying everything from Alibaba? In the US, a UL listed product will be safe.

Well, I'm in the US, though I think the UK plug is great. I've found tons of products even sold on amazon which are not UL listed. And most consumers don't realize how bad these things can be.

A lot of cheap stuff sold on Amazon is just stuff relisted off of Alibaba for a nice profit. In the US, UL compliance is voluntary for insurance reasons. If you go to Walmart or equivalent, most or all things will be UL listed.

Why? what solution would you replace it with?

The cheap tat sold on ebay is often terrifying if you're using UK wiring.

To be fair, there's nothing in the Part P regulations saying that you have to have a ring main. When I had my house rewired, I had the electrician put in radial circuits for the new wiring, so at least half of my outlets are now in a star topology.

Why fuses in the device?

Shouldn't you have RCCBs in your installation?

In new installations, you have both.

It's a nice story, but in modern times it's massively over engineered and really not practical.

I get that the voltages are higher but even that is a bit silly. In many ways the US system makes a lot more sense. 110V for most things and then 220V only for things that really need it (electric dryer, oven and such).

Well, in Europe we have 220V rated at 16A for most things (including electric dryers), and a 3-phase connector with up to 400V @ 32A only for things that really need it (oven) [1]. The higher voltage allows for less bulky connectors, cables and electric kettles which heat water in a reasonable amount of time. And honestly, the European systems (Schuko [2] and the UK plugs) look a lot safer than their US counterparts.

[1] https://en.wikipedia.org/wiki/IECEE [2] https://en.wikipedia.org/wiki/Schuko

Many US plugs are now designed with a guard, such that both main prongs must be present before the socket will open and allow either prong to enter (sticking a fork in one side won't open it). Voltages present at outlets in the US is also half of UK (and most of the world, I believe). Under most circumstances, it is not hazardous. It doesn't feel good to be hit with it, but it generally will not kill you or cause permanent damage. Notice I said most circumstances. There are a few things that can make even lower voltages lethal, such as the presence of water, a person with existing cardiac issues, or a small child, for example.

It appears also that the half-insulated conductors would present less surface area for contact with the mating outlet, possibly increasing resistance, which could be a problem with a high current load. Or is the mating outlet somehow designed to mitigate this?

My main complaint with the outlets in the USA is the contacts in the receptacle lose their grip over time, sometimes to the point of not even making connection with the inserted plug. Under a high-amperage load, this causes the outlet to heat up(due to increased resistance), even when the load is below the outlet's rating.

I believe these "tamper resistant" receptacles are actually required by electrical code, because apparently the NFPA has solved all the real problems [0]. A socket that sometimes decides to not "open" and bends up the plug's prongs is a terrible idea. And being able to stick in bare wires or test probes is a feature.

Contact mating happens at a few individual points, so the total area probably doesn't matter as much for conductivity.

[0] See also AFCIs, which greatly increase the cost of a circuit, leading to fewer circuits with more load on each one. Furthermore, each breaker is now running who-knows-what closed software. Somehow, an upgradability requirement was left out of the mandate.

I believe you are correct, for new construction.

Yes, thankfully we have the NFPA. Interestingly, I just attended a high-angle rescue course last week, taught by a highly trained firefighter with more than a few actual rescues under his belt. He explained that for he and his collegues, NFPA was generally agreed to be an acronym for No F*cking Practical Application.

Whenever practical, I avoid the tamper-resistant outlets. Many times just getting them to accept a plug is a challenge.

For those of you who didn't grow up in the US, touching the live ends of a partially plugged-in cord (and the corresponding sensation of having medium-voltage electricity rolling through your fingers) is an experience most people have had.

Just to add another anecdote to the mix: I've lived in the US all my life and I've never even heard of this happening.

Are these advantages reflected in electrocution and house fire rates?

Electrocution related to the plug happens too rarely to be statistically analyzed. This comes up in the parallel infinite arguments about 120 vs 240 volts, and 50 Hz vs 60 Hz.

In both countries more than half of electrocution deaths are pretty horrific overkill industrial accident or crane vs power line where the difference between two million times too much power flowing thru the body vs four million times too much power don't have much of an effect on the end result. Likewise a lot of home deaths need correction for alcohol and stupidity.

Isn't stupidity exactly what this plug is trying to solve? A toddler is stupid, there is no reason to allow him to electrocute himself. Darwin awards can be handed out to adults, but not to small children.

Public Information Film: Fix Things Properly.

https://www.youtube.com/watch?v=5N0ATdDdwKg

I fail to see how it has any security advantage over the continental types E anf F.

I'd love to see something like USB become the standard for supplying power. It would work for pretty much everything except heavier appliances, and remove the need for most things to have their own adapter. It would be much more efficient, and as a Brit, kinder on the feet.

And electrical saftey isn't what it was: a friend has an electric train set from the 30s which runs directly from the mains. A 60 watt lightbulb is wired up to the tracks to indicate when they're live, and the sparks and ozone smell when it's running is something to behold.

the main problem with 2-pin US NEMA-1 plug is its asymmetry of the blades, they have exactly the same thickness but with different width, I often make a mistake when I try to plug it in, if you rotate the plug and if you push hard, the plug fits in but the blade gets damaged. Australian ones are better, they have thin blades but wont go into socket if you rotate the plug.

Well this is the new UK standard from 1947. Before that was the considerably less safe type D plug.. still in use by former colonies.

They barely fit in a suitcase, so they're completely unsuitable for a nomad lifestyle (including jet-setting professionals). If they were at least flat, you might argue for them, but they're just a honking big cube, more or less.

http://www.themu.co.uk/

Down-voted? Almost anywhere else in the first world you travel from the US, the required adapter is about the size and shape of a matchbook, and easily slips into a side pocket of your roll-on bag or laptop case. For these UK monstrosities, there's no such hope, so you have to put them in the main body of your roll-on, and because of their 3-D nature, they interfere with the normal bin-packing of shirts and pants. Try it some time; I'm speaking from experience. And if you want to take two, you're really screwed.

Does the design improve surveillance security? Looks like the insulated plug prongs and the ground pin enablement features would help resist server plug capture devices for seizing servers while powered up.

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