Hi, i am putting a new light switch in and it has a black and red wire going into it, do i need to connect a earth cable into the light switch box? Thanks
Light Switch
- Thread starter pebbles36
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Let's work the other way round: does the cable have an earth wire?
If not, you must only fit a plastic switch.
If not, you must only fit a plastic switch.
It only has a black and red wires and no earth, ok thats a shame was hoping i could change my plastic light switch to a metal one. Thanks for that.
Have a careful look at the cable, there may be an earth conductor, but (in older installations) it was sometimes cut back.
If its there, you then need to test if it really is connected to the protective earth.
Per the above, if no earth, then no metal switches or metal fittings can be used unless they are double insulated.
If its there, you then need to test if it really is connected to the protective earth.
Per the above, if no earth, then no metal switches or metal fittings can be used unless they are double insulated.
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As previous post if no earth/CPC, Class I fittings cannot be installed, so class II/double insulated fittings need to be fitted.
It maybe possible that the earth/CPC has been cut back and could be enough to be able to amend this, so check within the outer sheath of both red and black conductors for bare copper. It could also be that it's a metallic conduit system and that is providing the earth.
If CPC is found it is very likely that you will need to tie in all the CPCs of the circuit to get continuity back to the fuse board/mains earth terminal.
So a continuity test would be required and confirmed as suitable.
It maybe possible that the earth/CPC has been cut back and could be enough to be able to amend this, so check within the outer sheath of both red and black conductors for bare copper. It could also be that it's a metallic conduit system and that is providing the earth.
If CPC is found it is very likely that you will need to tie in all the CPCs of the circuit to get continuity back to the fuse board/mains earth terminal.
So a continuity test would be required and confirmed as suitable.
I think i need to wear glasses as there is a earth wire there so pleased i can fit my metal light switch, i have tested it and is all ok 
back to orginal question and that is do i connet a small earth strap between the light switch and back box, sorry not sure what its called?? Thanks
back to orginal question and that is do i connet a small earth strap between the light switch and back box, sorry not sure what its called?? Thanks
Would depend on the lugs for the screws, if they are both adjustable then you should, if one or more rigid, then not required. belt/braces I would link across.
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