3 Prong *Plug* with no ground connection?

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I received this in an email from a friend while we were discussing some house wiring issues.
This friend lives in the UK. I find this hard to believe, so I thought I'd check here
He wrote:
"I was assuming (rightly or wrongly) that in the states, like us, some devices which are double insulated have a 3 prong plug moulded onto the cable but the ground prong is not actually wired up. Here, all of our plugs and wall sockests are 3 pin."
Do they (the UK) really use 3 pronged plugs without a ground wire connected to the ground pin on double insulated devices?
Does the NEC allow that in the US?
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On Fri, 2 Mar 2012 09:44:16 -0800 (PST), DerbyDad03

Can't speak about 3 prong but I have some single pole switches not grounded. In fact they don't have a ground connection on them. I do see the newer single pole switches with a ground screw that I just purchased this week at homedepot. My house has a grounding rod but I wonder why the couple of switches I saw were not grounded even tho I saw the ground wire inside the box twisted together but not connected to the switches I observed. I was tempted to jump wire them to the switch to ground it but I'm not sure if I would be doing more harm than good??? I'm a newbie in electrical wiring.
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That's right, the big UK plugs have identical pins for hot and neutral, so a plug without the ground pin would have no way to indicate polarization. Thus I can believe that even double-insulated appliances have a ground pin for that reason alone.
I have no idea if it's contrary to any standards in the US and Canada to have a ground pin where it's not needed, but I've never *noticed* a ground pin on anything marked with the double-insulated symbol.
Chip C
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Once again, the detail I am looking for is glaringly missing.
It's clear from all indications that the ground pin is present and that it's purpose is to force the correct orientation of the plug. I get that.
However, I still haven't seen a straightforward, dedicated answer to this question:
Is the ground pin is wired to the ground wire in the cord?
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On Fri, 02 Mar 2012 13:17:25 -0800, DerbyDad03 wrote:

If the cord *has* a ground wire, my expectation is that it would legally have to be, to avoid the situation where someone electrocuted themselves after re-using the plug/cord combo (assuming it had some form of plug/ socket at the far end rather than being hard-wired to the device) with a different (faulty) device where the ground was needed.
However, it used to be quite common for devices where there was no ground requirement (e.g. radios) to have only two wires (live and neutral) in the supply cord - no ground. In that situation, the earth (ground) pin would still be present in the plug, but obviously not connected to anything. Back then, all plugs could be taken apart by the end-user to get at the integral fuse though; at some point molded plugs started appearing (the fuse accessible via a trapdoor on the plug's underside) on new devices, and that's where I can't be 100% certain of the answer - I don't know for sure if two-core cords were outlawed at that stage or not.
The only UK-style molded plug I have with me in the US uses a three-core cord even though the device it powered has no ground requirement), but that's not really enough of a sample to deduce anything ;-)
Oh, the UK plug standard is BS13 (http://en.wikipedia.org/wiki/BS_1363) by the way, but I don't think the article says one way or the other about molded plugs on devices with no ground requirement.
cheers
Jules
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What I always wondered in a double insulated drill with no ground, if the operator accidently hits a power line say buried in a wall they could be electrocuted.
if the drill were grounded it would trip the breaker
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wrote:

metal parts that are connected to the "chassis" that could become "hot" and shock the operator.
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wrote:

wide/narrow blade combination.
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On 03/02/2012 04:06 PM, Chip C wrote:

Hmm.. that actually prompts another question now that I think about it. I know they use 240 over there. is it two opposing phases of 120, or is it hot/neutral as we use here for 120? If the former, there's no point in enforcing polarization in any case.
nate
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It would seem very dumb to have a plug with a ground prong and not have it connected to anything. I've never heard of it in the USA. What would be the point? To make people go find a 3 prong to 2 prong adapter when none is needed?
But as far as it being an NEC violation or safety issue, if it's only on appliances that are double insulated, it's misleading but not really a safety issue. Double insulated doesn't require a ground.
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wrote:

A key point in the comment from my UK friend was "Here, all of our plugs and wall sockests are 3 pin."
That would eliminate the need for a 2 prong adaptor regardless of whether the ground pin was wired or not.
I've never heard of it in the US either, but who has ever checked?
I've opened a few appliances over the years and as far as I recall, anything with a 3 pronged plug had a ground wire from the cord connected to the case.
Did I ever ohm it out to see if the ground pin itself was wired? No.
Have I checked every device with a 3 prong plug to see if the ground pin was wired? No again.
I'd be shocked (no pun intended) to learn that we (and even the UK) use three prong plugs with no ground wire to the pin, but I'm wondering if anyone knows for sure.
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On Fri, 02 Mar 2012 10:14:00 -0800, snipped-for-privacy@optonline.net wrote:

All (modern) UK AC outlets have built-in shutters which close off the holes for the AC feed when not in use; the ground (earth) pin on a plug is slightly longer than the two AC pins and its insertion into the outlet is what moves the shutter out of the way so that the plug's AC pins will go in.
For that reason you always see ground pins on UK plugs (and wall-wart type devices), even if the ground isn't actually required by the device.
cheers
Jules
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On Mar 2, 1:50pm, Jules Richardson

Thank you for that, but we're still missing a key detail here:
"even if the ground isn't actually required by the device" is different than "even if the ground pin isn't actually wired within the plug".
Do you know it to be true that there are molded plugs in the UK where the ground pin is not wired?
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On 03/02/12 02:08 pm, DerbyDad03 wrote:

It's been more than ten years since I was in the UK, but yes, I have seen devices with a two-conductor cord and a plug with a *plastic* "ground pin" that serves only to open the shutters and to ensure the correct polarity.
I don't recall what fuses -- and where -- are in devices that come with a preattached plug in the UK, but devices often came without a plug, probably because a variety of outlets were still in use: two small round pins (5A, I think), and three larger round pins (13A, I think) -- perhaps others as well, but those are the two I recall. The more recent system is to have an appropriately rated fuse in the plug: "spare" plugs typically came with a 13A fuse installed, but fuses were available in several different ratings, even as low as 1A, IIRC.
I could not find any last time I was there, but they used to have switched plugs (with slide switches on the edge of the plug opposite the cord entry), so that one didn't have to keep pulling the plugs out to disconnect the device altogether.
Perce
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On 3/2/2012 3:34 PM, Percival P. Cassidy wrote:

I'm curious but not enough to look it up but I wish one of our British friends could answer a question about their wall outlets. Here in the states a wall outlet installed for something like a large window AC unit that runs on 240VAC will not have a neutral if it's a 3 wire outlet. A ground and two hots which will measure 120VAC from the hot to ground or neutral because it's either phase A or B. On the U.K. outlets I'm wondering if there is only one 220VAC hot, one neutral and one ground/earth connection?
TDD
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On 03/02/12 05:08 pm, The Daring Dufas wrote:

As I recall, all 3-wire outlets in UK had one 240VAC "hot" (which I think they called "line"), one neutral and one ground.
Perce
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On 3/2/2012 4:40 PM, Percival P. Cassidy wrote:

Then that would explain the necessity of making sure the plug is inserted correctly. Of course, Europe uses 50 cycle power so their hum on the radio speaker is a lower tone. ^_^
TDD
TDD
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On Fri, 02 Mar 2012 17:40:11 -0500, Percival P. Cassidy wrote:

Close - it's live, neutral and earth, and the supply is indeed 240VAC (or thereabouts, ignoring voltage drops) running at 50Hz.
cheers
Jules
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On 03/02/2012 07:47 PM, Jules Richardson wrote:

Whipping out the British English to American English translator:
hot = live neutral = well, neutral earth = ground
so you'd both right :) (unless you're both wrong...)
nate
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On Sat, 03 Mar 2012 07:35:15 -0500, Nate Nagel wrote:

No, it was just the use of 'line' I was really commenting on; I've only ever heard it referred to as 'live' in the context of domestic UK AC supply. 'line' is used, IIRC, for HV transmission lines, but what's found in the home is always 'live'.
And yes, ground = earth; it's always earth in an AC supply context... after 4 years in the US I've just about got used to saying ground (and talking about wrenches instead of spanners etc. ;-)
cheers
Jules
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