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Earth cable live when live cable connected ?!

Posted: Sat Mar 07, 2009 4:34 pm
by antony5378
This is a bit puzzling.

I'm wiring a light switch in my kitchen, when i connect the lives from the ring to the live for the light, the earth cable is also living-up.

The earth is unconnected at both ends, so the current must be transferring from the live to the earth, without actually being in contact with it, how i do not know.

Any advice would be appreciated.

Posted: Sat Mar 07, 2009 8:58 pm
by kbrownie
hi anthony5378,
this is not good, i'd be checking all connection at light fitting for a loose earth or a loose live that are touching. Or connection that has been terminated wrongly. also check at cu in case it has happened there If you can not find it straight away call a electrician.
KB

Posted: Sat Mar 07, 2009 9:35 pm
by sparx
Hi, £ to a pile of rat sh@t you are using one of those bl00dy neon test screw driver things!!
Dangerously misleading pieces of junk which should be banned from sale for all time IMHO.
It's called 'capacitive coupling'. If you use a proper moving coil test meter you will find it is not actually live at all. If it where, connecting it to earth wires at ceiling would blow fuse/mcb.
NB "Capacitor" two parallel conducting surfaces seperated by insulating material, (ie, just like a twin & earth cable).
regards Sparx

Posted: Sun Mar 08, 2009 4:50 pm
by moggy1968
The other possibility is you've lost a neutral somewhere and the earth is now providing your neutral return path. This should trip the switch, but I have seen it when it doesn't. It could be an earth neutral reversal somewhere.
Andy