I wouldn't be surprised if it was just the grain, after all. Perhaps it's just the right texture to set off a vibration effect in the skin. I've no idea how you can verify that. But yes, I'll try to check the earth too.
I've told you one way - try it with the leccy off.
Doh! Of course. Thanks.
Is the box and screws and front panel earthed. If yes, then its not working! This electrostatic effect is often felt on brushed ally fronts of hi fis etc, but if the earth is connected to it, you should not feel it at all. Brian
Yup we call that the Shania Twains.. Seriously though, if the metal bit is not connected to anything, it will probably always be that way, just like a brushed ally knob on an old dimmer we had was as it was on a plastic spindle. Brian
However the long runs of water pipe seems to be normal and possibly to help with the flexing on g the modern thin mountings for the taps so they do not break a joint!
Brian
Yes I get that with my long white cane on the metal crook. I think there is a theory that we are sensitive to electrostatic changes. This is one theory on how divining works of course. Brian
Well, suggestion. Undo one of the screws, get a bit of stiff bare wire, and bend it so when you do the screw up it presses against the tingly surface, now test for tingle. if the tingle is there, then your earth lead is bust, if not then the metal you are touching is just stuck on and there is no connection to the earthed box. Probably quite safe, but if it worries you devise a cunning plan to connect it from behind to the box.
Brian
Maybe, but the problem is not so much that they are long, but rather 'jumbled up'. I'd have put two long straight pipes along the wall (hot and cold), and made connections behind the appliances where necessary. Here, they all meet under the sink with lots of short curved bits joined together. I can imagine that some of them are under a worrying amount of mechanical stress. Perhaps I should learn to worry a bit less :)
I've just had the multimeter out. I don't think the front plate is earthed. Measuring the resistance between it and other plates and screws in the vicinity also shows open circuit, whereas a measurement between any two other things shows that they are all connected. Even though this switch's metal box has an earth wire connected, and there is also one to the switch plate, I'll have to assume that the connection is lost somewhere in the wall or ceiling.
My guess is that the strange tingling sensation is this electrostatic effect that BG mentions; or electricity induced in the faceplate due to the proximity of the mains cable. Or is that what 'electrostatic effect' means?
It's definitely a solid metal plate. It's stamped out of a sheet of stainless steel. Just a flat square piece of metal screwed to the wall.
It isn't an electrostatic effect if it is being driven by mains voltage at 50Hz it is capacitive leakage between adjacent conductors or in the case of PC PSUs and HiFi the filter capacitors on the mains input leaking to a no good earth connection. You can feel tiny currents but it is as well to put things right before they get any worse!
Best guess is you have unearthed metal plate facing the end user.
Capacitive leakage. Yes, I can imagine that.
I've tested for conductivity between this metal plate and the others, and there is none. So, I'll have to find out where the earth wiring has broken.
How old is the wiring? As I said, at one time earths weren't required on lighting circuits.
If its wired using "loop in" wiring, then next most likely place for loss of earthing is at the ceiling rose where the switch cable will be connected.
Mid 80's
Thanks, I hope it's as simple as that.
Earthed lighting circuits came in around 1966...
Okay, I've done some testing with my multimeter. By connecting the probes against the screws of several light switches, and nearby mains sockets. I discovered that some of the light switch's earths aren't connected to some of the mains sockets' earths. I'd have expected them all to be connected, but I could be wrong. What's more, some of those screws are showing around
85V AC with another probe connected to a nearby mains socket screw, rising to about 120 when you switch one of the affected lights on. I don't suppose this is normal. None of the upstairs ones do this, but most of the downstairs ones do.Does any of this suggest anything obvious? I don't know what 120V feels like, but I don't feel anything alarming when I touch the screws on an affected switch. Although I might if I leaned over and touched a mains socket screw at the same time.
Do the same test with a 20kohm/ volt or even a 1kohm/ volt analogue meter, and they'll show zero volts to earth from the suspect faceplates. The voltage you describe is caused by capacitive coupling, which has a very high impedance at 50Hz, so while the virtual open circuit of a digital multimeter input shows a voltage, the much lower input impedance of a moving coil type meter will just short the voltage to earth. You could get a similar result by licking the tip of your finger before doing the brush test with it. The lower impedance when you touch it with a damp finger shorts the current, and hence the tingling, to earth before it affects your nerves.
The fault is that the metal faceplates that give you the tingle/ buzzing feeling aren't earthed. If the wiring or the switch fails in the wrong way, the faceplate could become fully live, which would give you rather more than a slight tingling feeling...
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