Shaver sockets

[swill453]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

Scott.

[Mike4]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

Scott.

A very good question I've often wondered too.

I wonder all the more because my shaver works equally well plugged into either voltage socket. How does that happen?!

[pje16]

because they don't need 240V shoved up them to work

[mc2fool]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

Because it's unlikely your American/Japanese/etc visitors will be bringing their own washing machine or vacuum cleaner in their luggage.

I wonder all the more because my shaver works equally well plugged into either voltage socket. How does that happen?

'Cos, like your laptop and other portable devices, it's cheaper to make them for "universal" supplies, i.e. 100-240V 50-60Hz, than it is not, and, of course, they want them to be usable anywhere.

[swill453]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

Because it's unlikely your American/Japanese/etc visitors will be bringing their own washing machine or vacuum cleaner in their luggage.

I'd say hairdryers/straighteners are just as likely, but not catered for.

Scott.

[mc2fool]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

Because it's unlikely your American/Japanese/etc visitors will be bringing their own washing machine or vacuum cleaner in their luggage.

I'd say hairdryers/straighteners are just as likely, but not catered for.

Scott.

Too much power. A typical hair dryer is 2000watts.

My hi-fi, bought some decades ago when I lived in the USA, is 110v and I have a 500W 110v-240v transformer for it. It's the size of a bag of sugar and weighs twice as much. There's just no way you could get that into a standard sized wall socket, or even behind most walls (let alone the heat problem), and that's just a quarter of the power. Shavers are only a few watts so the transformer is tiny and can be easily fitted inside a standard pattress.

Solid state ones may be smaller, but still ... try googling for a 2kw 110-240v converter or transformer and you'll see what I mean.

[Lootman]

Why on earth are bathroom shaver sockets dual voltage? How often does the 115V bit get used?

Is it for Americans? Why do we cater for them for razors but no other appliances?

In a few London hotels I have seen 110 volt US-style wall sockets by the desk, clearly designed for directly plugging in US laptops and similar devices.

The average American traveller is not going to buy an adaptor just for the UK, where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

[csearle]

The average American traveller is not going to buy an adaptor just for the UK, where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

That's what makes us so quirky and quaint. If it were not for quirky and quaintness¹ they wouldn't bother visiting! In fact I'd go so far as to say Americans are drawn to these islands primarily because of our plugs.

C.
¹ And that they feel they don't need to learn a different language.

[gryffron]

Because they can. Because it's easy and costs virtually nothing.

A shaver socket is floating voltage. Not tied to earth. Prevents you electrocuting yourself when it's wet. Or at least, it helps. This is implemented with a transformer. If you're going to provide a transformer for floating earth anyway, you might as well add an extra tap on it for 110v. It's simple. An extra feature that helps it sell and costs virtually nothing to implement. So why wouldn't any manufacturer include it?

Gryff

[csearle]

Prevents you electrocuting yourself when it's wet. Or at least, it helps.

Yes you could still kill yourself if you managed to grab hold of L in one hand and N in the other. But if you managed to grab hold of L in one and an earthed pipe in the other then there would be no circuit, so no (potentially lethal) current would flow. C.

[AF62]

where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Other than in Ireland, Sri Lanka, Kuwait, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Jordan, Macau, Brunei, Malaysia, Singapore, Kenya, Uganda, Nigeria, Iraq, Tanzania, Zambia and Zimbabwe.

[stewamax]

....we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Quirky yes - sensible even more so, since the sockets are shuttered - if the earth pin is not inserted the line (aaarrgh) and neutral remain shuttered

[Lootman]

where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Other than in Ireland, Sri Lanka, Kuwait, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Jordan, Macau, Brunei, Malaysia, Singapore, Kenya, Uganda, Nigeria, Iraq, Tanzania, Zambia and Zimbabwe.

Yes, some parts of the former Empire. Everywhere else has round pins of one form or another.

....we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Quirky yes - sensible even more so, since the sockets are shuttered - if the earth pin is not inserted the line (aaarrgh) and neutral remain shuttered

I am no electrician but I learned somewhere that we have an earth pin only because our appliances are not double-insulated. In the US 2-pin sockets are very common and somehow people there don't get electrocuted all the time.

[mc2fool]

where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Other than in Ireland, Sri Lanka, Kuwait, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Jordan, Macau, Brunei, Malaysia, Singapore, Kenya, Uganda, Nigeria, Iraq, Tanzania, Zambia and Zimbabwe.

Yes, some parts of the former Empire. Everywhere else has round pins of one form or another.

Except for the USA where they use quirky 2 flat pin plugs and sockets that you never see elsewhere. (Ok, N. & central American, Japan, and a few US "colonies" like Samoa, Marshall Island, etc).

I am no electrician but I learned somewhere that we have an earth pin only because our appliances are not double-insulated. In the US 2-pin sockets are very common and somehow people there don't get electrocuted all the time.

Well when I lived in the US in the 1980s pretty much all sockets were "type B", 2 flat pins plus a round pin for earth, and pretty much all appliances had a type B plug, other than lights, which had a just-the-2-flat-pins type A plug. Indeed:

"Since 1965, ungrounded type A outlets are not permitted anymore in new constructions in the United States and Canada, but they can still be found in older buildings."

"Type A and B plugs are not insulated (i.e. the pin shanks are not sleeved; they do not have a black covering towards the plug body like type C, G, I, L or N plugs) and the outlets are not recessed into the wall, which means that if a the plug is pulled halfway out, its prongs are still connected to the socket. Type A and B sockets are notoriously dangerous, since the distance between the receptacle and a partially pulled-out plug is big enough to touch the pins with your fingers or with a metal object such as a teaspoon."

https://www.worldstandards.eu/electricity/plugs-and-sockets/ab/ (Even has a short video to demonstrate...)

[csearle]

I am no electrician but I learned somewhere that we have an earth pin only because our appliances are not double-insulated. In the US 2-pin sockets are very common and somehow people there don't get electrocuted all the time.

I imagine some appliances in the US are not double insulated? Fridges, white goods, lathes, etc. No reason they couldn't be made double insulated but that would be very unlike our equipment here and in the EU. I imagine these come with three pins only so that they don't fit into the two-pin sockets? Conversely I imagine only double insulated equipment is supplied with two-pin plugs?

Some of the houses in Germany are essentially giant shaver sockets, in that the 230V power lines come into the attic, are transformed 1:1 via a biggish isolating transformer whose secondary winding is connected to line and neutral. This is called electrical separation. The Earth connections, if present, in the sockets are connected to an Earth stake. So just like a shaver socket if an occupant straddles between either line or neutral and earth then no appreciable current flows because there is no circuit¹.

Chris
¹ It is not the safest of arrangements because if two faults occur a dangerous situation could arise. So I believe they have equipment in them to monitor the insulation so that automatic disconnection occurs before a second fault can happen.

[Lootman]

where we use quirky 3-pin square plugs and sockets that you never see elsewhere.

Other than in Ireland, Sri Lanka, Kuwait, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Jordan, Macau, Brunei, Malaysia, Singapore, Kenya, Uganda, Nigeria, Iraq, Tanzania, Zambia and Zimbabwe.

Yes, some parts of the former Empire. Everywhere else has round pins of one form or another.

Except for the USA where they use quirky 2 flat pin plugs and sockets that you never see elsewhere. (Ok, N. & central American, Japan, and a few US "colonies" like Samoa, Marshall Island, etc).

I am no electrician but I learned somewhere that we have an earth pin only because our appliances are not double-insulated. In the US 2-pin sockets are very common and somehow people there don't get electrocuted all the time.

Well when I lived in the US in the 1980s pretty much all sockets were "type B", 2 flat pins plus a round pin for earth, and pretty much all appliances had a type B plug, other than lights, which had a just-the-2-flat-pins type A plug. Indeed:

"Since 1965, ungrounded type A outlets are not permitted anymore in new constructions in the United States and Canada, but they can still be found in older buildings."

"Type A and B plugs are not insulated (i.e. the pin shanks are not sleeved; they do not have a black covering towards the plug body like type C, G, I, L or N plugs) and the outlets are not recessed into the wall, which means that if a the plug is pulled halfway out, its prongs are still connected to the socket. Type A and B sockets are notoriously dangerous, since the distance between the receptacle and a partially pulled-out plug is big enough to touch the pins with your fingers or with a metal object such as a teaspoon."

In general electrical codes only apply to new installations, and there is no requirement to update old wiring that is not to code. I believe that is true both in the US and the UK.

In the UK it hardly matters because all sockets are 3-pins. (Of course the earth may not be connected but that is not something that can be determined visually).

In the US you get both 2-pin and 3-pin outlets, sometimes in the same house because some circuits may have been rewired but not others. And it gets annoying because if your appliance has a 3-pin plug then you can't insert it in a 2-pin outlet. Which is why 3-pin to 2-pin adaptors are very useful (you don't need the reverse, obviously).

So if you using an appliance there, then it is fairly random whether you will be earthed (or grounded, as they say there) or not. So presumably it doesn't matter too much either way, from a safety perspective.

I am no electrician but I learned somewhere that we have an earth pin only because our appliances are not double-insulated. In the US 2-pin sockets are very common and somehow people there don't get electrocuted all the time.

I imagine some appliances in the US are not double insulated? Fridges, white goods, lathes, etc. No reason they couldn't be made double insulated but that would be very unlike our equipment here and in the EU. I imagine these come with three pins only so that they don't fit into the two-pin sockets? Conversely I imagine only double insulated equipment is supplied with two-pin plugs?

Some of the houses in Germany are essentially giant shaver sockets, in that the 230V power lines come into the attic, are transformed 1:1 via a biggish isolating transformer whose secondary winding is connected to line and neutral. This is called electrical separation. The Earth connections, if present, in the sockets are connected to an Earth stake. So just like a shaver socket if an occupant straddles between either line or neutral and earth then no appreciable current flows because there is no circuit¹.

At least in California I know that the code says that each appliance in a kitchen must have its own separate circuit. So the fridge, dishwasher, cooker, hood fan, waste disposal etc. do not share any wiring. Then separate circuits for the countertop sockets and the lights. So a new kitchen can easily require a dozen circults, which may well mean you need a new junction box coming into the house!

But yes, all are three pins.

In older kitchens, the cooker may share a circuit with the lights!

[mc2fool]

Well when I lived in the US in the 1980s pretty much all sockets were "type B", 2 flat pins plus a round pin for earth, and pretty much all appliances had a type B plug, other than lights, which had a just-the-2-flat-pins type A plug. Indeed:

"Since 1965, ungrounded type A outlets are not permitted anymore in new constructions in the United States and Canada, but they can still be found in older buildings."

"Type A and B plugs are not insulated (i.e. the pin shanks are not sleeved; they do not have a black covering towards the plug body like type C, G, I, L or N plugs) and the outlets are not recessed into the wall, which means that if a the plug is pulled halfway out, its prongs are still connected to the socket. Type A and B sockets are notoriously dangerous, since the distance between the receptacle and a partially pulled-out plug is big enough to touch the pins with your fingers or with a metal object such as a teaspoon."

In general electrical codes only apply to new installations, and there is no requirement to update old wiring that is not to code. I believe that is true both in the US and the UK.

In the UK it hardly matters because all sockets are 3-pins.

Not necessarily. Unearthed sockets were withdrawn in 1970 in the UK but, just as you've seen in the US, there may still be such sockets in older houses. While most sockets in my mum's house had been changed to modern ones decades ago, it still had a couple of 5A two round pin lighting sockets up until it was sold two years ago.


https://www.plugsocketmuseum.nl/OldBritish2.html

At least in California I know that the code says that each appliance in a kitchen must have its own separate circuit. So the fridge, dishwasher, cooker, hood fan, waste disposal etc. do not share any wiring.

Cookers and tumble driers in the US run on 240V. Houses are supplied with a split phase 120V-N-120V supply, with the two 120V lines in exactly opposite phase (180deg) giving a 240V supply across the two (very useful to know for British expats!). Cookers and tumble driers use a chunky plug & socket to connect to that, although you don't normally see it as it's behind the appliance.


https://en.wikipedia.org/wiki/NEMA_connector#NEMA_14

[SteelCamel]

At least in California I know that the code says that each appliance in a kitchen must have its own separate circuit. So the fridge, dishwasher, cooker, hood fan, waste disposal etc. do not share any wiring. Then separate circuits for the countertop sockets and the lights. So a new kitchen can easily require a dozen circults, which may well mean you need a new junction box coming into the house!

The same was true in the UK, and that's exactly the issue that the 13A plug is designed to address. By including a fuse in the plug, you can have one circuit rated at 30A (or 32A) with multiple appliances, while still having each appliance protected by a suitably rated 13A (or less) fuse. Combine this with ring circuits, and there's a massive reduction in cable required (not to mention that at 240V the cables can be half as thick as at 120V). All of which is precisely what was intended, as there was a huge shortage of copper after the second world war, and a lot of new houses needing to be built.

[bungeejumper]

In the UK it hardly matters because all sockets are 3-pins. (Of course the earth may not be connected but that is not something that can be determined visually).

Easily determined with a simple plug-in socket tester. https://www.amazon.co.uk/Labgear-Socket ... B07PXN6C44 It also checks for reversed polarity and various other tricks. In fact, the only thing it really can't tell is whether the socket is fully on the ring main, or whether it's one of a daisy chain of spurs. (We've had tenants who've done that sort of stuff. ) I imagine that comparable testers are available for other countries' wiring systems?

In older kitchens, the cooker may share a circuit with the lights!

Not just kitchens. In my father in law's house, I found that the loft light had been wired down to the hot water cylinder. With a length of lamp flex. Could have burned the house down at any moment. And he was a British Telecom electrician!

BJ

[newlyretired]

In the UK it hardly matters because all sockets are 3-pins. (Of course the earth may not be connected but that is not something that can be determined visually).

Easily determined with a simple plug-in socket tester.
BJ

I think Lootman is talking about whether the appliance has a 2 wire or 3 wire connection, not whether the socket is correctly wired.

newlyretired