In message , "Dave Plowman (News)" writes
Excuse my french - but what's a noggin? I'm going to run a single 1.0mm earth wire to a socket down the edge of a door frame, all sheathed by graan/yellow. Bit of a pain in the arse, but nothing compared to the grief from the girlf of having a plastic socket in a house full of stainless ones....
A lath and plaster wall is hollow. It's constructed out of vertical studs. But at perhaps two places there will be horizontal 'noggins' to add strength and prevent twisting. These also stop you just dropping a cable from top to bottom. But you can channel out over the noggin and bring the cable round over it, then make good.
Running an extra cable off to some other circuit to pick up an earth is itself a bit of a bodge (not a terrible one, but definitely not best practice); the "fully right" thing to do is to rewire your downstairs lighting circuit with new cable which includes the earth conductor. You'll be able to reuse most or all of the existing cable route, but if the old stuff is plastered in you'll get plenty of practice in applying one-coat patching plaster!
Unearthed lighting circuits wnet out-of-regs at least 30 years ago, which suggests your downstairs circuit cable is coming to the end of its useful. It's not that likely to be the original 30s you mentioned in a previous post - back then it would've been rubber-sheathed, and you'd find that the insulation would be crumbling off it the moment you unscrewed the old fittings and moved the cable around a bit. (If that *is* happening, BTW, you need to rewire *urgently*, as the risk of sparks and in the worst case fire is well above neglible...)
HTH - Stefek
Borrowing an earth connection from the socket circuit is against regs, as its possible someone could one day disconnect the socket cct, but leave the lights powered up. However, it will clearly greatly increase the safety of your dodgy setup.
Uhoh. If its really that old, or even 40s or 50s, dangers are bound to be lurking. The number 2 rule with really old wiring is dont move it, not even slightly. A quarter inch of movement is enough to cause a short or fire if the rubber's perished - and it normally is.
The number 1 rule? Disconnect it and rewire. 1930s wiring is anything but safe: in fact 30s wiring in the condition it will be in today would have been condemned even back in the 30s. I dont know when lighting had to have earths, but 2 core lighting is very old, and probably well past its reasonably safe by date.
I _really_ wouldnt want metal light switches on a dodgy setup like that. Even when earthed, the level of shock protection is liable to be real poor, and the odds of earthed things going live quite high. Why? High earth impedances, wire fuses, no RCD, no crossbonding, no earthing on parts of the install, heavily corroded wiring, high probability of shorts, high leakage... no thank you. get it fixed.
Regards, NT
In message , Stefek Zaba writes
I've had a look round the rest of the downstairs cabling. Only the kitchen and the lounge have no earth, so it looks like the rest of it has been redone at some point. The lounge wiring looks in pretty good condition, it does look like a grey rubber sheath on the wiring but its not flaking at all. I've already got the new earth cable hidden behind the door frame, but I haven't yet cabled it to the socket (going to make it flush fit later this week).
If it's grey, it's probably PVC. Rubber outer was normally black. But is there an earth conductor inside? Might well have been cut off at the ends.
The sure way would be to measure the size of the conductor with a micrometer or similar. Rubber cable if single strand will be 0.044 in or if stranded will have three 0.029. These sizes also existed with early PVC cables. Post '70 or so cables will be single strand metric.
IMHO OP should determine if its grey pvc or grey lead, they can look similar. A superficial metal scrape will reveal either bright metallic lead or lighter grey pvc.
NT
In message , N. Thornton writes
It's lighter grey pvc, and there's definitely no third core earth wire.
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