no N in switch
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s1bgs
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no N in switch

by s1bgs » Fri Feb 06, 2009 2:07 pm

2 way lighting on landing and in hall d/stairs.
From landing light to landing switch the N has been left out. t/w been used for 2/way instead of 3 core is this the norm?

sparx
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by sparx » Fri Feb 06, 2009 7:35 pm

hi,
switches don't need and rarely have a neutral core, ie, just a live in & switch line back which is often incorrectly coloured black or blue, leading people to think there is a N.
There is then normally a 3core with earth between switches to convert to a 2way circuit.
Occasionally people have tried to change a 1 way cable to 2 way by using the earth core sleeved over as a switch line, but wrong on 2 fronts, first no earth in circuit & insulation not continuous where sleeving meets cable sheath.
regards SPARX

dunabit
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Re: no N in switch

by dunabit » Fri Feb 06, 2009 9:54 pm

[quote="s1bgs"]2 way lighting on landing and in hall d/stairs.
From landing light to landing switch the N has been left out. t/w been used for 2/way instead of 3 core is this the norm?[/quote]

its normal to have 2 conductors from the landing light to the first switch . then 3 conductors from the first to second switch
( t&e from lumanaire to switch 1, then 3 core & earth between switches )

singer
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by singer » Fri Feb 06, 2009 10:35 pm

To add to what sparx has said from your description it sounds like the 2 way light has picked up a feed from hall switch, is using a twin for strappers between switches and is using the red core in a twin with the black chopped out as the switch wire to the landing light fitting. Thats why the black is not being used - I guess!
Nothing wrong with that as long as it works and all switches have an earth.

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