Electrical – How to wire a ceiling rose

electricallight-fixturelighting

I have bought a new ceiling rose for a light. The wires in it are UK pre-2004. There's one black, two red, one yellow, one blue, and two green and yellow earth. Where do all these go on the ceiling rose?

Best Answer

enter image description here

Often, electricians used ordinary black/red/green twin&earth for C but marked the black wire with red tape (to indicate "switched live")

You seem to have something nonstandard, perhaps a spur (therefore missing B) without an earth to the switch? You'll have to use appropriate methods to determine what is what.

See answer to similar old question https://diy.stackexchange.com/a/32251/2815