how to put up a light fitting wi a loop in syatem ?

the earth will have its own connection in the rose

mm
July 2013

do you have a test meter ??if not get a pro in what peccavi is saying you have a loop in loop out system if you have a test meter then turn power off take all wires out of the rose,connect your meter to one pair of wires,get some one to turn the switch on and off,do this with all wires,when you find the wires that go open circuit when you turn the switch on and off these are the switch wires,now connect one side of the switch wire to the flexi cable the wire that goes to your bulb connection,and put the other to the centre connection of your rose then put the remaing red wires to the centre connection,put the black wires to the neutral side of your flexi cable

mm
July 2013

All the reds join together - none of the reds go to the light.

One of the reds is power coming in
Another red is power going off to the next fitting
A third red is power going off to the switch

One of the blacks is neutral back to (from) the consumer unit
Another black is neutral running to the next fitting

These two blacks connect together and the new light connects to them as well

The third black wire (your challenge is to identify it) is not a neutral at all - it's switched live - live only when the switch is set to on. It is this wire that connects to the other side of the new light.
Sometimes it has an identifying marker sleeve on it to show that it's switched live.

The earth connects to the metalwork (if any) of the new fitting - for safety.

Remember Lord Finchley...

Lord Finchley tried to mend the Electric Light
Himself. It struck him dead: And serve him right!
It is the business of the wealthy man
To give employment to the artisan.

Peccavi
July 2013