Is it normal to feel a very mild buzzing/tingling sensation from a metal light switch plate? You can only feel it if you gently run a finger at right angles to the 'grain' on the brushed metal surface. There's only one in the house, so I can't compare it to any others. It all looks fine inside the box.
Fine includes the backbox having an earth connection, presumably? Does the switch have a double insulated "square within a square" logo on it?
No. It suggests that the metal isn't earthed and a leakage path to live.
I expect it will also light one of those neon screwdrivers we are not supposed to use any more due to strange elfin safety rulz.
On Monday 03 June 2013 10:06 Ivan Dobsky wrote in uk.d-i-y:
Barring some really weird problem, my conclusion is:
Your earthing is buggered to that switch.
Get it checked IMMEDIATELY by someone competant...
It's not "normal" - it's presumed dangerous.
Yes, the box is earthed. I'll have to check for the logo later.
I forgot to mention that there are several metal mains outlets that do not feel like this, so I have to assume something's wrong.
Thanks, everyone. I'll get it checked.
Previous owner said the kitchen (including electrics) was fitted by Moben, and seemed quite proud of it. A few things I've seen in there don't impress me very much.
The only one I have has a battery in it (so you can use it to test fuses and things), and seems to light up whatever you touch.
Just because it has an earth wire doesn't mean it's actually earthed. Could be a break in the wiring elsewhere. You need to check the earth at that point - or have it checked professionally.
Do you mean sockets? At one time it wasn't required to have an earth circuit connected on lighting circuits - even although TW&E cable was used. 3 pin sockets have always required an earth connection.
Given you say you only feel it when stroking one way, might be worth checking if you still feel it with the relevant circuit switched off. (doing it blind, ie get somebody else to switch but not tell you which way, means you also eliminate potential bias, but I appreciate that may be getting harder :-) ). If so, it's something other than the leccy and not a problem, and you've saved yourself some grief.
Yes, I mean sockets.
On Monday 03 June 2013 10:28 Ivan Dobsky wrote in uk.d-i-y:
There may be a causal link between "Moben" and "not impressed"...
There just might be. The most annoying thing is the waste pipe under the sink that goes upwards an inch or so before it goes outside. The hot/cold plumbing under the sink seems unnecessarily complicated, too. It's like a pile of trombones under there. There's a twin socket right under this lot, too. I'm sure there should be something covering them, in case there's a leak under the sink.
Agreed. The op also said it was buzzing and that could be a suppression choke vibrating at 50/100 Hz which would be no problem at all.
That will be a tiny bit of leakage from the mains. All satellite boxes do it as long as they aren't earthed via the dish or the TV connection. You rub your finger along the case and you feel a tingle; press hard and you feel nothing. The switch must be lacking an earth connection.
Bill
Kitchen fitters make shit electricians. One bloody idiot was quite happy to have the dishwasher and w/machine both plugged into a 4-way trailing outlet left under the kickboard. Said 4-way was hard-wired into the back of a double socket. Ffs.
I probably should have used a word other than 'buzzing', but it is not a sound, just the way it feels, and I can't think of a better word. It's not really a tingle, either. You can only feel it when you very lightly brush your fingertips across the plate, and it seems to vibrate. You can't feel it when you just touch it. It's quite hard to describe. If you've ever walked under overhead cables with an umbrella, and gently rubbed the stem, you can feel something similar.
I can believe it. It all looks very nice from the front, as it were; but behind and underneath, there are a few things I wouldn't have done.
I get the same on the laptops, which both have two core mains leads. It's a few microamps of leakage current, and in your case, it means that the faceplate isn't earthed, and there's a very high resistance leakage path from the live inside the box to the faceplate. Worth investigating further in case something goes more seriously wrong.
Why would the OP feel it if he brushes his finger one way and not the other?
I'm voting for it being something to do with the grain, but I'd check out the earthing too.
Yes, press hard (or just touch) and you don't feel it. There is an earth connection in there (first thing I looked for), but I've not checked that it's actually connected to anything once the wire disappears into the hole.
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