# Electric plugs/ Why Dual Sized Prongs ? **URL:** \ **Category:** Factual Questions\ **Created:** [April 9, 2009, 2:45am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471 "2009-04-09T02:45:15Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![HongKongFooey](https://avatars.discourse-cdn.com/v4/letter/h/c4cdca/32.png) [@HongKongFooey](https://boards.straightdope.com/u/HongKongFooey)\ **Post date:** [April 9, 2009, 9:11pm UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/21 "2009-04-09T21:11:44Z")
> [@StinkyBurrito](#): > > Switching to polarized plugs simply requires changing out the socket. Switching to 3 prongs (and actually making it work) means rewiring the whole house in most cases. Chances are that if your outlets are only two slots, then there are only two wires running to the outlet and the third wire to carry the ground was never installed (if it was, they probably would have installed the corresponding 3 prong outlets at the same time). For those with two-prong outlets, adding a GFCI to the circuit will provide some protection and will protect all the other receptacles on the circuit if they are the first one on the circuit. > [@sailor](#): > > \ Europeans have not found any advantage in using polarized plugs, something which pretty much costs nothing and yields some safety. > > I favor polarized plugs. I agree 100%. Too many people underestimate the danger of 120V, never mind 230V. An electrician in the northern part of the province inadvertently wired a light socket the wrong way making the socket hot. His mother grabbed the lamp, got locked on to it, and was killed. Such an easy mistake to make, and could still happen with polarized outlets, but it does drive home the need to be aware of polarity with such things. ---
**Author:** ![gaffa](https://avatars.discourse-cdn.com/v4/letter/g/e68b1a/32.png) [@gaffa](https://boards.straightdope.com/u/gaffa)\ **Post date:** [April 10, 2009, 2:21am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/22 "2009-04-10T02:21:47Z")
> [@sailor](#): > > This is true but European grounded plugs are bulkier and more uncomfortable to use. British plugs are ridiculously big for some thin cable used with some small appliance. Yeah, but that probably dates back to appliances being sold without plugs. And the plugs tending to have fuses in them. > [@](#): > > As far as I know ever country in Europe uses the [Edison screw - Wikipedia](http://en.wikipedia.org/wiki/Edison_screw) lightbulbs and the sockets are similar to American sockets. Really? I didn’t try to unscrew any of the bulbs when visiting friends in the UK, but I have seen British movies where the character replaced a lamp that had a bayonet mount. And the film _Amélie_ definitely featured bayonet lamps. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [April 10, 2009, 3:09am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/23 "2009-04-10T03:09:26Z")
> [@sailor](#): > > As far as I know ever country in Europe uses the [Edison screw - Wikipedia](http://en.wikipedia.org/wiki/Edison_screw) lightbulbs and the sockets are similar to American sockets. You better check on that - we have a whole house worth of useless British lamps, some of them less than 10 years old, which only use bayonet-style bulbs. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 10, 2009, 8:34am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/24 "2009-04-10T08:34:25Z")
Yes, the new plug pins which only have metal tips and the base of the pin is plastic are safer. I once had a nasty accident with an extension cord where the base of the pins were exposed and could be shorted with something like the blade of a knife getting betwwen the two connectors. Of course, you would think that is highly unlikely to happen by accident and that’s what I thought. I waked with my drill out into the yard, pulling the plugged-in extension cord behind me. And the connection managed to fall on the aluminum track of the sliding door just right for it to short and make a huge spark before the circuit breaker tripped. The mark remained on the track as a reminder. Now I will often cover the gap with insulating tape if it is more than just a momentary thing. This accident would not have happened with modern European plugs. On the other hand, as I say, I find European plugs, specially the schuko type, just too bulky. And they require deeper space in the wall because they are sunk into the wall. UK plugs need to be fused because of the ring configuration of circuits in the UK. It is a different concept which relies on the protection being at the plug. But this makes the plugs just huge. IMHO many appliances which are not connected to protective earth _should_ be connected. I am thinking of metal lamps, some switching power supplies for laptops etc. They should, for different reasons, all be grounded. Yes, I am aware that bayonet lamps were common in the UK in the past but I see them less and less. I think the edison thread is becoming the norm. I would favor a lightbulb base where the outside part of the thread which might be accessible is either grounded if metal or made of insulating material. The contacts should both be not accessible. This could be done in several ways. One is the old bayonet system which is also used in cars. I do not favor this for homes as it is more expensive and prone to breaking. I would favor a base with concentric contacts, similar to three-way lamps. Or just two pins which fit into a socket. A schuko plug could work. The edison socket where the thread can be energised should be inadmissible. But it is the world standard today and is not going away any time soon. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 10, 2009, 8:37am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/25 "2009-04-10T08:37:59Z")
> [@HongKongFooey](#): > > I agree 100%. Too many people underestimate the danger of 120V, never mind 230V. An electrician in the northern part of the province inadvertently wired a light socket the wrong way making the socket hot. When you have non-polarized plugs, like in most of Europe, you cannot know if the socket will be connected to the hot wire and that is why I would favor (a) polarized connectors and (b) sockets where the user cannot touch anything carrying electricity. ---
**Author:** ![Rayne\_Man](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Rayne\_Man](https://boards.straightdope.com/u/Rayne_Man)\ **Post date:** [April 10, 2009, 9:48am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/26 "2009-04-10T09:48:10Z")
> [@gaffa](#): > > Really? I didn’t try to unscrew any of the bulbs when visiting friends in the UK, but I have seen British movies where the character replaced a lamp that had a bayonet mount. And the film _Amélie_ definitely featured bayonet lamps. In the UK we now have a choice of at least four types of light-bulb fittings. The main ones are large bayonet, small bayonet, large Edison screw and small Edison screw. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 10, 2009, 11:39am UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/27 "2009-04-10T11:39:38Z")
Large and small edison screw exist in every country I know of. I think Bayonet are not as common in the UK as they once were. I have memories that they were dominant but it could be my own biased memories. ---
**Author:** ![Myglaren](https://avatars.discourse-cdn.com/v4/letter/m/f1d935/32.png) [@Myglaren](https://boards.straightdope.com/u/Myglaren)\ **Post date:** [April 10, 2009, 12:14pm UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/28 "2009-04-10T12:14:01Z")
Bayonet fittings were almost exclusive in the UK until about fifteen years ago. The only exceptions I can recall were photographic lamps. (oddly enough this arrangement was reversed in Sweden and possibly the other Scandinavian countries. if not elsewhere in Europe) The proliferation of European and Scandinavian luminaries on sale now in the UK has brought about the change to a more diverse selection of bulb fittings. IKEA probably the progenitors of the revolution 🙂 **Una** , you may be able to replace the UK bayonet bulb holders to the US standard ones. I did this to all ours when we moved here from Sweden in '79. Still have the odd one hanging around. If I’d waited we could just have bought the right bulbs - now ☹ ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 10, 2009, 3:07pm UTC](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471/29 "2009-04-10T15:07:48Z")
As engineers say, the good thing about standards is that there’s so many of them to choose from. [Previous page](https://boards.straightdope.com/t/electric-plugs-why-dual-sized-prongs/492471.md?page=1)