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!)
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)
If it was just a tingle, for a second or so, then it could just have been static building up on your clothes (nylon underwear) and being drawn away to earth through the socket cover.
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.......
I would be tempted to check that both sockets are properly earthed, both the one you touched and the adjacent one. Checking that they are both at the same potential with an ohm meter would be a good start. Try it on ac volts first of all. It is not unheard of for earth wire to become disconnected elsewhere in the circuit and this would not at first be apparent as it would not stop appliances from working. Best of luck and take care.
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.
No chance. Static builds up to si high a voltage that even with several megaohms in the path to earth, it discharges damn quickly, and won't give any kind of "sustained 50Hz tingle" like wot our original poster got. (And if there was that kind of resistance in the path to earth, the socket's earth connection's not exactly in order!).
From the details given, there's a (possibly intermittent) fault which needs sorting out. It's not clear from what we've heard whether the socket was the source of the 'tingle', with mains current passing through the OP's body on its way to earth, or its 'sink' - for example, if there's a floorboard nail which is just about contact with a live (only), and the OP stands on it, the surrounding floorboards won't give a decent path to earth so our man won't feel anything; but touching a well-earthed point
- the socket cover if all the wiring's in order - creates a path to earth which our man can feel. (In such a case the strength of the 'tingle' is much dependant on how effective a contact he has with the source: do a trick like this in bare feet and you might not wake up at all :-(
Other uglies can happen with TV/video/sat etc. kit: some of these have two-pin mains connectors, and then internal circuitry which makes the aerial outer float to halfway between the live and neutral voltages. The resistance is high enough not to make the amount of current which flows dangerous to life, but you still feel a real and unpleasant tingle if you become the earth path for this voltage.
I'd definitely want to know what caused the 'tingle': what's an unpleasant weirdness on one occasion can become something much more dangerous next time.
If you're in a 1st floor flat then you dont really need an RCD for 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.
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 :-}
Yes, quite right, but... 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.
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.
Do explain further, Bob: tell us how the "ridiculous obsession" meant that "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...
There isn't actually a requirement for supplementary bonding to be 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.
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