Trying to electrocute myself

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I touched one of my electrical sockets the other day and could feel electricity (they have metal covers). It wasn't powerful enough to hurt like it did when I touched the live wire to the cooker, but it was fairly strong and I could feel the 50hz.
Been trying all day today and I can't electrocute myself this time, darn it. What could the fault possibly have been? I've unscrewed the thing and everything seems to be firmly attached inside including the earth loop. The adjacent socket didn't have the same problem, although I wondered whether I might have been touching something else that's live and was just creating a circuit by touching the socket. But nothing seems a likely candidate.
Any ideas greatly appreciated. (Obviously I'm keen to sort this out and don't really take electrical safety lightly!)
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Do you know what sort of electricity supply you have to your premises ? (are you fed from overhead lines or cables clipped along a row of houses or is the cable underground for as far as the eye can see)
Bear in mind that electricity companies are not legally obliged to provide an earth, and in many cases may not be able to provide one for one of several reasons:
- structures of a temporary nature (portacabins etc) - farms or where livestock are held - overhead lines often don`t have an earth provision - same goes for clipped (sometimes known as cleated or mural) wiring - network conditions may not allow... one area nearby has a "tidal" earth where the area is essentially built on sand. When the tide comes in you get a great earth, but when it goes out again...
Do you have any sort of safety devices fitted, like an RCD ? - if you have an older type of device it might be worth getting that replaced for a start (my knowledge is a little weak in this area).
When you had the front of the socket off, did you notice any damage to the insulation ? (sometimes cables can be pressed hard against each other damaging the insulation)
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Colin Wilson wrote:

No overhead lines around here -- very urban. The city's main substation is less than a mile away.

It's a converted mid-victorian terrace flat. The wiring in the flat is great but the part downstairs where the metres are is very old and dodgy so there could be anything going on.

Is that something old? Could be that if so.

No I don't have an RCD but I thinking I really need one. They are just installed in series before the consumer unit aren't they, sounds like an easy job?

I'll have another check tomorrow when I'm more sober.......
Thanks for your help
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Doesn`t mean the mains in the area aren`t old and provide you with an earth...

Are you paying rent, or is it privately owned ? - i`m wondering whether a landlord might have any responsibility for wiring. The submain will probably belong to the landlord and not the electricity company, and it isn`t unknown for these to fail. As the electricity supplier isn`t obliged to provide an earth, it will probably be the landlords responsibility to make sure adequate provision is in place. Not sure what the hell you`d need to do it its privately owned :-}

You`d see it clipped along the front of the houses adjacent i`d guess...

Where`s your consumer unit (fuse board) - i`m guessing its in the flat.
The ideal way would probably be to fit a new consumer unit that can split the load into RCD protected and non-RCD protected (lights are generally better off non-RCD protected from what I remember of sparking, but its been a while :-} )
If you are paying rent though, i`d report it to the landlord and ask him to get it checked out.
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anything other than the shower. The RCD is required for socket outlets that are reasonably expected to supply portable equipment for use outdoors. Not all that likely in an upstairs flat.
SJW A.C.S. Ltd.
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What about leakage through the consumer to any bonded pipework etc ?
At least the RCD would trip rather than still being potentially fatal.
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wrote:

a 'normal' split load setup in a 'normal' house?
SJW A.C.S. Ltd.
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Lights can be prone to nuisance trips when lamps blow, but (and i`m probably wrong, haven`t played with wiring for years :-} ) I think the general idea is lights tend to have less that can go wrong with them, and taking the safety factor of being thrown into complete darkness, the RCD tends to go onto "power" circuits :-}
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wrote:

Assuming we're talking about a installation up to required standards then there would be adequate earth bonding to ensure zero potential between pipework and other surfaces, thus no current to travel anywhere surely. If you were going to start altering the consumer unit on an old installation it would not be a good idea to ignore the other aspects affecting the safety of the installation, e.g. earthing arrangements. Although in one way of thinking you are not making it any worse you may well be not be making it better. Yes, if there wasn't adequate earthing in the property I would say you would be correct and there could be different potentials between adjecant exposed metallic surfaces, that's what the earthing is designed to prevent, when done correctly.
SJW A.C.S. Ltd.
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There was a fault in my parent's house where the old aluminium earth wiring had broken. This was revealed when thanks to this ridiculous obsession with bonding everything to "earth" in the bathroom, a second fault made all the fittings live. The equipotential bit certainly worked - shame it was all at 240v and not 0v.
The moral of this story? Connecting all the metal bits of a bathroom together isn't necessarily such a safe thing to have to do.
Bob
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The moral of this story is to do things correctly - they should have been bonded to a true earth, not just some earth wire anywhere. That's why *proper* earth bonding involves running back to the central earth point - not just tapping off ring main earths etc.
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Dave Plowman snipped-for-privacy@argonet.co.uk London SW 12
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connected to earth, in many cases it will be, but only because some part of the supplementary bonded stuff happens to be earthed for other reasons.
The supplementary bonding will do its job even if it's not connected to earth, if everything conductive in the bathroom is bonded together you can't get a shock unless you stick your hand out of the door and touch something earthy outside.
--
Chris Green

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regulations it basically all adds up to "connect all metal bits together" The supplementary bonding connected to metalwork will be connected to the main service pipes, (even with plastic in the middle, those bits need to be 'bridged'), they will be connected to each other at the mains end with equipotential bonding thus connecting all exposed metal work. This will also connect all socket screws, light fittings etc.. So there is no 'direct' regulation stating that supplementary bonding should be connected to earth but the earthing system as a whole is designed so that it is.

SJW A.C.S. Ltd.
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If there are mostly plastic pipes there is no requirement to bond any metal bits on them (e.g. taps or maybe the odd union), thus this *won't* be connected to the main incoming pipework, which is quite likely to be plastic nowadays anyaway. So no necessary connection to earth here.

electrical with exposed metal parts (quite likely in a bathroom) there is again no need for the supplementary bonding to be connected to the electrical earth. (Is that right, I don't have my OSG to hand, it *may* be that electrical equipment earths should be connected to supplementary bonding, not absolutely sure - however if there's no electrical equipment in the zones my comment still applies)
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On 28 Jan 2004 09:20:35 GMT, snipped-for-privacy@isbd.co.uk wrote:

O.k, if the installation is all in plastic then yes, but my comments were more based on the more common installations of metalwork, (which is what the posters saying it is wrong to have supplementary earthing have so that is what I chose to comment on, plastic isn't relevant to this particular conversation).

I never said there should, I was meaning in the property in general.

No, you would still have to bond pipework together.

I didn't say connect it directly, I said it is connected by default, i.e. all earths connected together at the CU. More than likely the earth path from supplementary bonded metalwork will end up connected here.

SJW A.C.S. Ltd.
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connection and doesn't work by being connected to earth.
It may well be that in many installations (e.g. where all pipework is copper) the supplementary bonded metalwork in the bathroom is connected to earth but that isn't what makes it useful.
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Chris Green

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On 28 Jan 2004 14:50:30 GMT, snipped-for-privacy@isbd.co.uk wrote:

I know.

metalwork to the same potential, (not neccesarily 0v though). See, I do know. In 'most' cases it would be connected to earth, fine, I'm not disagreeing.
SJW A.C.S. Ltd.
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"all" the fittings were "at" 240V. Hint: that'd be 240V relative to what?
Clearly, if *some* conductive surfaces in a bathroom become live, i.e. attain the potential of the incoming mains' live wire, and stay at that potential without causing a large fault current to flow so interrupting the supply (which is the first line of defence) because of the absence of an effective connection to earth, while *other* conductive surfaces *are* effectively connected to earth, there will be a shocking potential difference between the first and second group of surfaces. And that's dangerous. And avoiding that difference is exactly why everything with exposed metal surfaces which might foreseeably become live is supposed to be bonded together. That's the whole idea of, and the reason for the name of, "supplementary" bonding. Nowhere in that idea, or its detailed implementation in millions of households, is there a requirment that this stuff be bonded "to earth", btw: the point is to provide *supplementary* protection so that *regardless* of whether the whole "house earth" is at local ground potential, there's no dangerous *local* difference in potentials between the different conductive objects *in* *the* *bathroom* *itself*.
There are indeed other ways of guarding against dangers to life from electrical faults; and avoiding *any* path to earth in a particular working environment is one such. But it's not a practical option for normal bathrooms in normal houses, wot with all those copper cold water pipes and the like. (Yes, Hep2O does make a difference; and the IEE Regs recognise that difference, making rather different recommendations for all-plastic plumbing installs.)
But, as I said, please do explain your comments about the ridiculous obsession...
Stefek
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240V relative to the floor they were standing on, of course. Just because all the metal bits are joined together doesn't mean that if they end up connected to the live instead of earth wire that you won't get a shock. You could always try holding a live wire if you don't think I'm right.
I did post a couple of years ago about this subject - ie what is the point of earth bonding, but no-one could answer at the time. From recent posts I can see what the reason is, but my point is that earth bonding protects against one kind of fault only. I'm just giving an example where it made the fault more dangerous.
Bob
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What sort of bathroom floor has enough conductivity to give you a powerful enough shock to kill you? Typically, a bathroom floor will be timber, plastic, stone or ceramic. All are excellent insulators and will not support the levels of current needed for a dangerous current flow.
Christian.
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