my bathroom lights have no earth but all parts are plastic.i want to fit metal downlighters run off the same rose and switch does it need earthing.if so can i connect earth to ring main circuit as thers a spare cable from an old heater

daz, March 2007

Yes metal downlighters will need earthed. The earth in a flat grey cable might well have been cut back and/or it may not be sleeved, ie it will be bare copper. You can see if it has been cut back if there is any slack in the wire to pull through and examine where the red/black wires meet the grey sleeving. . . but never force the cable in any way and always turn off at the fuseboard/consumer unit before going near any wiring. I am assuming there is only 1 flat cable connecting at the rose, if there are more they should all be connected to a common earth terminal inside the ceiling rose. I would not advise taking an earth from anywhere else, especially in a bathroom. Oh yeah, if the downlighters are SELV then they may not need earthed after all . . .

tim, April 2007

if your lighting circuit is wired with flat grey cable,as is the norm, it will have an earth which should be terminated in the ceiling rose even if nothing else is connected to it. If it doesn't I would guess it has been fitted by a DIY/cowboy, get the job done properly for the safety of yourself and others.

Pete, March 2007