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[Gall]

Hi, I hope some one can clear this up, I have be trying to fit a new ceiling light. I removed the ceiling rose and made a note of the wiring. When I wired the wires up to the connector block the light worked but it could not be turned off. ie the switch was not working. I have noted fom previous projects listed here that there a three red wire and 3 black one on which is the switch live. But the wireing in the ceiling I have came across has 4 red wires can anyone explain this :x

[333rocky333]

As you read there is usually three reds these are permenently live, if you connect to them your light will be perm on.
The switch return goes on + off .
It is only black because t+e cable is usually used to the switch and is made with red and black cores, the electric flows down the red and back via the black core and must not be mistaken for neutral which is always black,
The installer should have sleeved or marked the switch return red.

T+E Cable was made with two red cores for wiring to switches,but was rarely used,or if your wiring is in pipe the switch return would also be red.
It is therefore possible your switch return could be red or black,you will need someone competent to test which one is the return from the switch.
Newer installs will be brown and blue cores

[sparx]

Hi Gall, as 333rocky333 says it is usual to have three reds & 3 blacks at rose, if you have 4 then either person who wired it used the correct twin red as sw. drop in which case you will only have 2 blacks, or if you also have 4 blacks then an additional light has been looped from fitting.
If 2 blks only then look at cables and find the one with 2 reds in same cable, one of them is your sw. return to lights live flex, 2 blks to lights Neutral remaining reds together in spare 'loop-in' term block.
I always used twin red for sw. drops, & now use twin browns, but wholesalers say only one other firm in area also use it!
regards SPARX