I recently replaced a ceiling rose in the bedroom of my flat and found the wiring to be quite odd..
1 single black wire sheathed in grey
1 single black wire sheathed in grey
1 twin cable black/red sheathed in grey (black wire has brown sleeve on it )
This was wired both single black wires together connected to light neutral.
Red cable from twin cable to light live. black with brown sleeve to earth terminal on rose..
All the lights seem to work ok but this seems an odd system
1 single black wire sheathed in grey
1 single black wire sheathed in grey
1 twin cable black/red sheathed in grey (black wire has brown sleeve on it )
This was wired both single black wires together connected to light neutral.
Red cable from twin cable to light live. black with brown sleeve to earth terminal on rose..
All the lights seem to work ok but this seems an odd system