Straight Dope Message Board

[dstarfire]

Why does British culture treat electrical outlets as so incredibly dangerous? Is there some historical reason, or is it just part of the general European health and safety culture? ("health and safety" is sort of like the UK equivalent of "political correctness")

On an old episode of QI (a British panel show) the host (and some of the panelists as well) seemed very nervous about bare ends of a speaker wire (which they'd been told and shown was connected to a speaker out jack). And in a youtube video, the host remarked that the shutters over the slot in a multi-socket outlet (for fitting a variety of plug types) were cheap because you could easily poke something stiff like a knitting needle through them, and how the standard British socket was so much safer because it's shutters only unlocked after the ground prong was inserted. Standard Brit plugs have to be coated in a nonconductive material except for a portion at the tip so somebody can't shock themselves on a plug that's not fully inserted. Also, codes prohibit any electrical outlets in the bathroom (aside from a low-power thing for shavers).

Note: not saying it's right or wrong, just why it's so different. The question could as easily be why is America so casual about the dangers of electricity.

[scr4]

Their outlets are 240V, which is far more dangerous than the 120V used in the US.

My understanding is that other European countries that use 240V power require similar safety features on their outlets.

[Dewey Finn]

A related question; in the UK, didn't small electrical devices come without the plug attached, so you had to add one after you bring the device home?

[friedo]

Originally Posted by scr4

Their outlets are 240V, which is far more dangerous than the 120V used in the US.

My understanding is that other European countries that use 240V power require similar safety features on their outlets.

They don't. Other European countries don't have fused power cords or mandatory switched receptacles everywhere. The UK's odd safety requirements are largely a product of the thoroughly demented ring mains system which is nearly unique to those isles.

[leahcim]

Video from Tom Scott on the British plug: https://www.youtube.com/watch?v=UEfP1OKKz_Q

Two interesting bits that might explain safety (in addition to the 240V thing):

(1) Up until 1992 appliances didn't come with plugs attached and you were expected to wire your own plugs -- if every Tom, Dick, and Harry is wiring a plug, the safety features need to be more conspicuous and fool proof. And if nothing else, it puts plug safety on the common man's mind.

(2) The standard was set during a time of copper shortage so houses were wired with a single loop instead of separate circuits, with fuses in the plugs for safety.

Mostly I think it's just the British culture allows for more safety regulations (video on that: https://www.youtube.com/watch?v=CTmLU9VOJlM )

[GMANCANADA]

I asked the same exact question a couple years ago, it became a long thread. Bottom line is that it's not based on any rational thing (like practical safety concerns), mostly just Brit's incredible slowness & resistance to change. Keeping to tradition, even when that tradition is no longer required due to tech (like GFCI receptacles etc), is part of their cultural identity.

https://boards.straightdope.com/sdmb...d.php?t=813795

[ThelmaLou]

I bought an electric teakettle in the UK in 1983 and didn't notice (it was in a box) that it didn't come with a plug--back then you had to add your own over there (as mentioned upthread). Many years later over here, a friend wired it and somehow attached it to the 240 plug that operated my electric stove. But it never quite worked. It never got hot enough to boil water.

Now electric teakettles are all over the US, not so when I made that trip.

[Steven_G]

Originally Posted by GMANCANADA

I asked the same exact question a couple years ago, it became a long thread. Bottom line is that it's not based on any rational thing (like practical safety concerns), mostly just Brit's incredible slowness & resistance to change. Keeping to tradition, even when that tradition is no longer required due to tech (like GFCI receptacles etc), is part of their cultural identity.

https://boards.straightdope.com/sdmb...d.php?t=813795

This is not at all accurate. There are real concerns, for example up to a few years ago (maybe now as well) electrical faults were the cause of a high proportion of domestic house fires. The rest of Europe also uses 220v, but wiring is on a "star/hub" basis, allowing the use of trip fuses on circuits. Post-war UK had a real copper shortage, and the ring main was adopted to help. Maybe it's correct that that needs to be superseded, but no more than the US using 110v with the need for even more conductor, high currents and slow electric kettles

And now all appliances come with a moulded-on plug.

[Mijin]

Before people bash brits too much, as someone who travels a lot, I appreciate the design of the sturdy 3-pin plugs:
You almost never see a flash of electricity when plugging devices, and it holds securely in the socket even if there is some pull on the cable. The Chinese and US 3-pin are OK but I think are still not standard in either country IME.
ETA: plus it has a fuse

[friedo]

Originally Posted by Steven_G

This is not at all accurate. There are real concerns, for example up to a few years ago (maybe now as well) electrical faults were the cause of a high proportion of domestic house fires. The rest of Europe also uses 220v, but wiring is on a "star/hub" basis, allowing the use of trip fuses on circuits. Post-war UK had a real copper shortage, and the ring main was adopted to help. Maybe it's correct that that needs to be superseded, but no more than the US using 110v with the need for even more conductor, high currents and slow electric kettles

It's 240, not 220. (I have no idea why this nonsense persists, even among professional electricians. It's never been 220.)

And every residence in the US has 240v service. The North American standard uses a center-tapped neutral to provide 120v (not 110) to small appliance and lighting loads. Large appliances like electric ovens, water heaters, dryers, etc. use 240v. (NOT 220 )

[Grim Render]

Because UK houses then to be crammed tightly together in row after row of attached housing sharing walls I expect. Fires can be much more destructive than in nations with more spaced-out housing.

Which again comes from the most desired parts of the nation being incredibly tightly populated, and the housing being quite old.

I've generally found the Uk to be very slapdash in their attitude to health and safety.

[PatrickLondon]

Originally Posted by Steven_G

Post-war UK had a real copper shortage, and the ring main was adopted to help. Maybe it's correct that that needs to be superseded,.

Having grown up in a house with prewar wiring, where it was all too easy to blow a fuse by loading too much on to the limited number of sockets, and every blown fuse meant traipsing down to the cellar to identify which one had blown, and rewiring it with the right weight of fusewire (assuming someone had remembered to keep the stock up to date and in its proper place), ring mains and fused sockets and plugs were a godsend. And who's going to pay for rewiring all the houses where they still work perfectly well?

[GMANCANADA]

@Steven G. - NEWSFLASH - the war ended 70 years ago!! To suggest that the UK can't update electrical codes in 2019 due to copper shortages from the post war era is ridiculous.

At some point they could have said "for newly built homes, here a new modernized electrical code..."

If you read through the old thread, there are lots of very valid historical reasons (like yours) for why the UK has the standards they do, but no valid reasons at all about why they remain so in 2019.

[Banksiaman]

This thread inspired me to see what the stats were.

This site offers a table [Fig 1] with deaths per million from electrical injuries in Europe.

The range for males runs from 0.2 in Netherlands right up to 25.2 in Uzbekistan [faaaark!]. The UK is 6th lowest at 1.0 per million. Couldn't find a US figure that seemed comparable,

But don't use a toaster in Uzbekistan, if you value your life.

[bob++]

It's a common misconception that Ring Final Circuits were introduced to save copper:

UK fixed wiring circuits, unlike 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.[3]) 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.

The current recommendation is to wire groups of sockets as a spur from the Consumer Unit. The reasoning is that it makes testing and fault finding easier. A connection on a radial circuit will stay live, even if there is a break in the circuit.

[Mijin]

Originally Posted by Grim Render

I've generally found the Uk to be very slapdash in their attitude to health and safety.

Probably not the best thread to make that point, since as implied by my earlier post, the UK socket design is arguably the safest in the world.

[upend]

Originally Posted by GMANCANADA

@Steven G. - NEWSFLASH - the war ended 70 years ago!! To suggest that the UK can't update electrical codes in 2019 due to copper shortages from the post war era is ridiculous.

At some point they could have said "for newly built homes, here a new modernized electrical code..."

If you read through the old thread, there are lots of very valid historical reasons (like yours) for why the UK has the standards they do, but no valid reasons at all about why they remain so in 2019.

but what driver is there to change to something arguably less safe?

[senoy]

Originally Posted by friedo

It's 240, not 220. (I have no idea why this nonsense persists, even among professional electricians. It's never been 220.)

And every residence in the US has 240v service. The North American standard uses a center-tapped neutral to provide 120v (not 110) to small appliance and lighting loads. Large appliances like electric ovens, water heaters, dryers, etc. use 240v. (NOT 220 )

It actually averages about 117 at point of usage. 120 is the 'shooting for' point at the site of delivery. It actually ranges from 114-126. Due to wire losses in the home, anywhere between 108 and 126 at the outlet is within spec. Technically speaking, regs will allow as low as 110 at delivery and 104 at the outlet, but those are supposed to be only in rare situations and if common should be considered a problem to be rectified.

[SamuelA]

Originally Posted by bob++

It's a common misconception that Ring Final Circuits were introduced to save copper:

The current recommendation is to wire groups of sockets as a spur from the Consumer Unit. The reasoning is that it makes testing and fault finding easier. A connection on a radial circuit will stay live, even if there is a break in the circuit.

So this means no more new ring mains? Those always did seem like a neat way to save copper since you get current able to flow down both halves of the main and you can have very high current draw from any given socket on the main. This in turn means that there's no problem running a vacuum cleaner, use very high power and rapid kettles and induction hobs and so on.

[Grim Render]

Originally Posted by Mijin

Probably not the best thread to make that point, since as implied by my earlier post, the UK socket design is arguably the safest in the world.

Yes, it is a peculiar exception to the rule.

[Really Not All That Bright]

Originally Posted by GMANCANADA

I asked the same exact question a couple years ago, it became a long thread. Bottom line is that it's not based on any rational thing (like practical safety concerns), mostly just Brit's incredible slowness & resistance to change. Keeping to tradition, even when that tradition is no longer required due to tech (like GFCI receptacles etc), is part of their cultural identity.

https://boards.straightdope.com/sdmb...d.php?t=813795

That wasn't the bottom line at all. Ring mains might be a bad idea, but mandatory switched receptacles are among the most obviously good ideas there are. US Type A electrical plugs and sockets are possibly the worst-designed objects in common use (Type B is slightly better). I think part of the misunderstanding is the belief that having a socket switch is only useful because it saves power. On the contrary, the most useful aspect of the switch is that the plug doesn't begin drawing current as soon as you plug it in. Anyone who's plugged a North American TV into a socket that's hidden behind some furniture has probably been shocked at some point, because the plug and socket are live as soon as the pins go in. Generally not fatal with 120V mains, but pretty fucking unpleasant.

[filmstar-en]

Wikipedia is most forthcoming on the subject. The UK standard was created by a committee formed for the purpose and headed by a remarkable woman electrical engineer who was very concerned about electrical safety in the home but very aware of liberating effect on the lives of women of electrically powered appliances in the home.

There is surely a movie script there?

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

The standard was devised during a time in the UK when everything was centrally planned for the war effort. I guess in the US the standards were arrived at as a result of patent wars.

Did the UK end up with a better standard because of this?

I think so. The UK plug is remarkably safe and solid design. No sparky accidental disconnections.

[yabob]

Originally Posted by Banksiaman

This thread inspired me to see what the stats were.

This site offers a table [Fig 1] with deaths per million from electrical injuries in Europe.

The range for males runs from 0.2 in Netherlands right up to 25.2 in Uzbekistan [faaaark!]. The UK is 6th lowest at 1.0 per million. Couldn't find a US figure that seemed comparable,

But don't use a toaster in Uzbekistan, if you value your life.

BTW, that doesn't seem to correlate with plug type and voltages:

https://www.worldstandards.eu/electr...ge-by-country/

Netherlands - 230V, C/F type plugs. Uzbekistan is 220V, C/F plugs. Most of Europe, in fact, uses C and F type:

https://www.worldstandards.eu/electr...s-and-sockets/

I think the major factor is probably public education concerning safe use of electrical devices, not the connector type. Actually, I like the F type plug from the standpoint of convenience - it's not polarized, so you don't have fumble around figuring out which way it goes into the socket, but it's still a grounded plug design.

[RaftPeople]

Originally Posted by Really Not All That Bright

On the contrary, the most useful aspect of the switch is that the plug doesn't begin drawing current as soon as you plug it in. Anyone who's plugged a North American TV into a socket that's hidden behind some furniture has probably been shocked at some point, because the plug and socket are live as soon as the pins go in. Generally not fatal with 120V mains, but pretty fucking unpleasant.

Mildly funny story:
I was in 7th grade Electronics class using the oscilloscope at my desk when it was time to put everything away. I tried to unplug it but the outlet was really tight and it only came about half way out. I thought to myself "man, I need a better grip on that thing" and proceeded to wrap my hand around it with my fingers touching the prongs.

After I let go due to the shock, I had a little laugh that I made that mistake in Electronics class.

[SanVito]

Originally Posted by Grim Render

Yes, it is a peculiar exception to the rule.

I think we're going to need some cite for this 'rule' which only you seem to think exists

[Really Not All That Bright]

The only thing I can think of is that cost and historic preservation sometimes outweigh safety - such as when a listed building doesn't get a fire escape because it would require modifying the fabric of the building. That's hardly a UK-specific thing, though (see - every building in Italy).

[Mk VII]

At one time there existed a considerable number of two-pin 2A, three-pin 3A and 5A (and indeed 15A, though that was usually only found on electric stoves) sockets in houses, many of which were built before electricity was common in the home.
As a result manufacturers could never tell what kind of plug an appliance would require, and so left it with bare wires. You would get the retailer to fit a plug, or the more proficient could do it themselves (we always did).
My house, built in 1951, came with 5A sockets all on separate spurs going back to the fusebox. All except for one, which was tried into the ground floor lighting circuit, because some electrician couldn't be bothered to do his job properly. Later my father added a ring main with BS1336 13A sockets, which we thought was a great advance and much safer.

You can still get the old sockets, if you know where to look, and I've even seen a recently refurbished house where new ones have been fitted. Though I can't think why they used them.

[ticker]

Originally Posted by Mk VII

You can still get the old sockets, if you know where to look, and I've even seen a recently refurbished house where new ones have been fitted. Though I can't think why they used them.

You sometimes get a lighting circuit installed with small round-pin plugs so you can control table and floor standing lamps from a wall socket. They use a different plug to discourage you plugging in high-power appliances which would trip the breaker.

[Steven_G]

Originally Posted by friedo

It's 240, not 220. (I have no idea why this nonsense persists, even among professional electricians. It's never been 220.)

Typo. Officially its 230v

[Steven_G]

Originally Posted by bob++

It's a common misconception that Ring Final Circuits were introduced to save copper:

But your citation supports the "misconception". Cheaper and more efficient due to using a lower quantity of expensive materials to get the desired effect.

[Melbourne]

Originally Posted by Really Not All That Bright

That wasn't the bottom line at all. Ring mains might be a bad idea, but mandatory switched receptacles are among the most obviously good ideas there are. US Type A electrical plugs and sockets are possibly the worst-designed objects in common use (Type B is slightly better). I think part of the misunderstanding is the belief that having a socket switch is only useful because it saves power. On the contrary, the most useful aspect of the switch is that the plug doesn't begin drawing current as soon as you plug it in. Anyone who's plugged a North American TV into a socket that's hidden behind some furniture has probably been shocked at some point, because the plug and socket are live as soon as the pins go in. Generally not fatal with 120V mains, but pretty fucking unpleasant.

We have switched sockets in Aus, but actually my TV is plugged into a power board behind the TV. I've never been shocked by it.

We don't use sockets for lighting in Aus, as we did in Arizona in the 60's, so in Melbourne we've never had sockets controlled by a separate wall switch as we did in Phoenix.

[GMANCANADA]

@ Really not at all that bright -
I have no disagreement about the plug design, but I struggle with the individually switched wall receptacles being a "good" idea. When I was last in the UK, I was told unanimously that they were there to save electricity. When I posted this question previously I was informed they were actually for safety, so that one could switch the receptacle off if the appliance caught fire (although it seems to me that is very rare). Now you're saying that they're used for safety when you put in / out plugs? But I thought the plug design was the safest in the world - why then is this redundancy needed?

If this is such a "good" safety feature why doesn't anyone know about it? It seems to me the ignorance of it's purpose defeats the purpose.

BTW - I have never once been shocked by an appliance while using my "world worst design" North American style plug - every house I've lived in for the last 25 years has GFCI receptacles which prevent that. Do they not have these mandated in the UK? If so, are the plugs, switches and GFCI now triple super, hyper, mega safety redundancies?

Regarding "what's the harm": in talking with a couple of electricians I know, they said they cost of the receptacle would be significantly higher but the cost of wiring every receptacle in a house so each could be individually switched would also be dramatically higher. (Can any Doper electricians confirm or deny this?)

I'd suggest the driver behind these so-called "worlds best safety measures" is a very powerful electricians guild lobby group who have a vested self-interest over-engineering safety features. They make a lot of money (and suck that money out of the public's pockets and the UK economy) by promoting fear.

[echoreply]

Other than the size drawback, UK outlets do seem superior to the US.

What about light switches? Many, most, all? of the kitchens and bathrooms (loos?) use pull cords to turn the lights on and off, instead of a standard wall mounted light switch. I think there is still some fear of electricity going on with that, though I'm happy to have it explained how a non-conductive pull cord from a ceiling mounted switch is an important safety feature around water.

Originally Posted by ThelmaLou

I bought an electric teakettle in the UK in 1983 and didn't notice (it was in a box) that it didn't come with a plug--back then you had to add your own over there (as mentioned upthread). Many years later over here, a friend wired it and somehow attached it to the 240 plug that operated my electric stove. But it never quite worked. It never got hot enough to boil water.

I imported a UK kettle to the US specifically to remove the UK plug and install a NEMA 6-20P on it. Then I could plug it into a 240V 20amp outlet intended for a window AC in my old condo. If I ever redo the kitchen in my house I'll add a 240 outlet. It worked fantastic and boils water in about a third the time of a regular US 120v kettle. It's a difference of about 2800 watts in the UK to 1500 watts in the US, which is a big deal when you want a cuppa.

[SamuelA]

Originally Posted by GMANCANADA

Regarding "what's the harm": in talking with a couple of electricians I know, they said they cost of the receptacle would be significantly higher but the cost of wiring every receptacle in a house so each could be individually switched would also be dramatically higher. (Can any Doper electricians confirm or deny this?)

I'd suggest the driver behind these so-called "worlds best safety measures" is a very powerful electricians guild lobby group who have a vested self-interest over-engineering safety features. They make a lot of money (and suck that money out of the public's pockets and the UK economy) by promoting fear.

The switch is built into the receptacle itself. It's not a separate component requiring additional labor to wire in.

By U.S. prices, a light switch is about $1, and a basic electrical outlet is also about a dollar. So it would be $2 for a combo switched outlet. You also need a slightly larger box so maybe another buck in materials there.

Even with slightly higher prices in Britain, and accounting for even higher prices before the 2000s with Chinese mass manufacturing, it wouldn't have made much difference.

[Magiver]

The UK shutter socket design has migrated over to the US and is code for new construction in my area. they don't add that much to construction cost.

The plug is a great idea but having consumers install them made no sense at all. Not even a little.

what I would like to see, and I think it's British thing, are junction boxes with built in busses. Instead of pig-tailing wire with wire nuts you just connect them to a bus. Really cleans up the real estate behind sockets and switches. The closest I've found are wago lever nuts. I'd like them built into the box.

[friedo]

Those wago nuts are great.

An even simpler solution might be to just get some small subpanel bus bars and install those in a junction box. Dunno if it would meet code tho.

[bob++]

One big advantage of having a switch on a power socket is that you can turn the power to an appliance off without pulling the plug out. It is generally recognised that one of the most painful things around is to step on an upturned plug top with bare feet

These things evolve over time: When I was a young man in the 50s/60s plugs had round pins and sockets and no switches. Getting a shock by touching a live pin was not uncommon. Most light switches were metal and not earthed, so shocks from badly wired light switches were common too. Stragely, now that they are all earthed, shocks from static are common; not so lethal though.

Typically, a house would be wired with one light in the middle of the ceiling and one single power socket. Of course, as appliances became more available, people just made 'Christmas trees' of adaptors to run the new TV, the old wireless (radio), a 3Kw electric fire, a floor lamp, and on wash days, an electric iron. When I lived in 'digs' the power socket was on a meter that I had to feed with coins, so I did my ironing and even heated the room, by plugging everything into the light socket.

With all this, and remember that everyone had to fit their own plugs, you can see the potential for shocks and fires - it's no wonder that the rules were tightened up and dire warnings given out on public media.

[SanVito]

I remember plug wiring being a mandatory class during one of our physics lessons in my girl's school in the mid 80s.

Even though we now have plugs fitted as standard, it's amazing how often this useful skill comes into its own, such as fitting a plug to a vintage shop sign the other week.

[Mk VII]

I would expect to have switches on all sockets, unless they were things that are 'always on'. There's no upside to not having one.

Wiring a plug correctly is one of the life skills everyone should possess.

I too, can remember 'digs' where there was just a single gas ring to cook on, and no electrical socket at all in the room, just one out on the landing. The place hadn't been updated since the 1940s, right in the centre of town, too. This was in the 1980s.

[Colophon]

Originally Posted by friedo

It's 240, not 220. (I have no idea why this nonsense persists, even among professional electricians. It's never been 220.)

Actually it's officially 230V, nowadays. Before 2003 it was nominally 240V in the UK and 220V in mainland Europe, but now it's 230V in both. However there is a 10% wiggle room either side so in effect nothing changed. Cite.

[filmstar-en]

The lady with the lovely hair, Dr Suzannah Lipscomb, talks to some experts about how hazardous it was in the early days of electricity in the home.

https://www.youtube.com/watch?v=i7kxUyvkXjw

[DrCube]

Originally Posted by friedo

It's 240, not 220. (I have no idea why this nonsense persists, even among professional electricians. It's never been 220.)

And every residence in the US has 240v service. The North American standard uses a center-tapped neutral to provide 120v (not 110) to small appliance and lighting loads. Large appliances like electric ovens, water heaters, dryers, etc. use 240v. (NOT 220 )

I wouldn't say "never", at least in the US. Edison settled on a 110V standard, to ensure 100V at the point of delivery. I have no experience with 110/220/440 standards, but I've seen them on old electrical drawings. We nominally use 120/240/480 in the US now, but I think in the past 110/220/440 was common, with possible intermediate values of 115/230/460, and the language is still used by a lot of people who talk about it. I know I was confused because I had heard it both ways, until I had to work on low voltage stuff and read the local power company's service manual.

[PatrickLondon]

Originally Posted by bob++

Stragely, now that they are all earthed, shocks from static are common; not so lethal though.

Tell me about it. Every damn winter, until I finally put inline switches on all the table lamps.

[yabob]

Originally Posted by filmstar-en

The lady with the lovely hair, Dr Suzannah Lipscomb, talks to some experts about how hazardous it was in the early days of electricity in the home.

https://www.youtube.com/watch?v=i7kxUyvkXjw

The first US president to live in the White House after it was wired for electricity in 1891 was Benjamin Harrison. He and his wife refused to touch the light switches for fear of being electrocuted - they made the domestic staff do it. That may have been an overreaction (as well as possibly saying something about his attitude towards the domestic staff if he thought it wasn't safe to operate the light switches). But, yeah, 19th century electric wiring was not very safe, and it was also often used in horribly unsafe ways, as there was an explosion of new gadgets powered off home electricity.

[md2000]

I was in a fairly new hotel in Las Vegas (The Venetian) in 2002. I plugged in my charger for my fancy new digital camera before going to bed. The next morning, a mile down the strip, I realized the battery had almost no charge. Checking later, the culprit was the wall socket. The room light switch by the door turned the bottom socket of the dual socket on and off, the top socket was always live. At one point, someone unaware of this setup had moved the table lamp to the top socket, leaving the bottom socket empty. So I'd plugged in the charger, we went to bed and turned off the room lights, and the charger went off.

This is a not-uncommon North American setup - where a room, typically a living room, has provision for a free-standing or swag lamp (remember those?) it would be driven by a socket in the room that was controlled by a wall switch near the entrance to the room. But... I don't remember running across other setups where the one socket is switched but not the other. that take some interesting wiring.

[Pantastic]

Originally Posted by Really Not All That Bright

Anyone who's plugged a North American TV into a socket that's hidden behind some furniture has probably been shocked at some point, because the plug and socket are live as soon as the pins go in. Generally not fatal with 120V mains, but pretty fucking unpleasant.

I have lived my entire life in the US and have plugged in many appliances, and have never been shocked plugging a plug into a properly functioning socket. Where do you get the idea that shocking yourself while plugging in appliances is common in the US? (I have been shocked when there was some kind of fault where the screw holding the socket in place was electrified, but that's not the fault of plug design). The idea of plugging in a TV by somehow holding the metal prongs of the plug is bizarre, I'm not sure what would even prompt someone to do that instead of just holding it by the plastic part.

Originally Posted by bob++

One big advantage of having a switch on a power socket is that you can turn the power to an appliance off without pulling the plug out. It is generally recognised that one of the most painful things around is to step on an upturned plug top with bare feet

This is why my appliances all either have an off switch or are something you don't turn off (like an alarm clock). The idea of leaving appliances with unplugged plugs sitting around is just weird to me, and the majority of plugs that I use are in locations where getting to the plug itself is difficult (behind a couch, bed, table, etc).

[kferr]

I have a George Foreman grill that doesn't have its own power switch so a switched socket is really useful.

[casdave]

The current recommendation is to wire groups of sockets as a spur from the Consumer Unit. The reasoning is that it makes testing and fault finding easier. A connection on a radial circuit will stay live, even if there is a break in the circuit.

I'm gonna need a cite here because the current recommendation is to evaluate each circuit in the design stage and decide upon the method of installation based upon allowed disconnection times - and this can vary according to many situations such as length of run, current to be supplied, environment and protective device - that's just a short list.

The spur circuit to which you refer is in fact called a radial circuit and is not a common method of installation - being usually confined to specific purpose outlets such as supply to your garage, outdoor waterproof outlets etc

So, if you can quote me the IEEE On Site Guide or the current wiring regulations that give this advice as a default instead of an option I would be really grateful.

Ring circuits offer more flexibility post installation because they make it possible to run radial spurs from them - a serious limitation of a radial circuit is that if you need to add more services there is a strong possibility that you cannot because you may have runs that are too long which will lead to unacceptable disconnection times, or even (though unlikely and somewhat counter intuitively) the volt drop across the run is not acceptable or perhaps the possibility of overloading the conductors closest to the source (the reason being that installation is often done at the very limits of acceptability in new build)


As for our plugs, if you are non UK then you may not be aware of our protective device arrangements. In a ring main the protective device is most likely to be 40amp to 60 amp - so if you develop a fault in an appliance whose power cord rating is 13 amp - well you can see the problem, so instead we also have a fuse in the plug itself. This means power cords can be rated for as little as 3 amps because we install a 3 amp fuse to protect that appliance..

The protective device in the mains box is there to protect the wiring, not the appliance.

Nowadays we use Residual current devices, these are similar to the US version of GFCI however, GFCI tended to be voltage operated whereas Residual current devices are, you guessed it - current operated, and were far more sensitive and also discriminate better - that is, you get far fewer false trip outs and also the protective device nearest to the fault is more likely to trip out, instead of a fault blacking out the who house through less discriminating devices.

I believe that the sensitivity of GFCI has caught up over the years, but you could only operate Residual Current Devices (RCDs) in an installed earth system.

Another hugely significant difference between UK systems is that we use installed earths - so we have a 3 wire system. I know that many appliances are 2 wire because they are classed as double insulated but the wiring back to the main dist board is still 3 wire.

There are pros and cons to this approach, but it is easier to protect from certain fault conditions by detecting current flow to ground and protective device fault disconnection is faster.

The UK system is less likely to lead to fires caused by fault current overload - there are many situations where a fault current can flow and overheat a device such that it will burn, and yet the overcurrent is not sufficient to trip the protective device in the dist board, this is why having the fuse in the plug is far better.

[Pushkin]

Originally Posted by Dewey Finn

A related question; in the UK, didn't small electrical devices come without the plug attached, so you had to add one after you bring the device home?

Years ago yes.

It's why Dad kept a supply in the garage. Also why you couldn't leave anything electrical he didn't recognise as his in there, he'd whip the plug off nice and quickly for you.

[ToughLife]

having the fuse in the plug is far better.

not really, fuse is obvious overkill.
The entire world ( with some exceptions)
lives without fuses in the plugs.
The fridge that burnt Greenfield Tower down had a 3a fuse.
Didn't help much, did it ?