I am trying to put a new light fitting on my landing. The new light is earthed so I know I need to cap off that one. My problem is I have 4 each of red and black wires. The new fitting only has space for 1 of each so how do I go about wiring it and knowing which is the correct wire to use?
The standard ceiling rose has four connections.
1) Line feed
Normally there are three cables
1) Feed in
3) Feed out (Next lamp)
The latter may be duplicated.
The "Switch" cable should have two reds or two browns according to age of the wiring but often the same cable is used as for rest of wiring and a red or brown sleeve or tape identifies this wire as the line return from switch.
It is very important to identify the line return from switch and if the sleeve or tape is missing replace this first so it does not get mixed up with neutral.
The rose will normally have a row of three connectors.
A) Two way (line from switch)
B) Three way (centre)
C) Three way (neutral)
So look for which side of rose has just a two way connector to identify which is line from switch.
Note:- Both Line and Neutral are regarded as Live hence the use of word Line for phase wire in single phase supplies. There are plans in projects section which show how it is wired.
It is common to use a connector for all the red wires and hide it in the ceiling void but really one should not do this as anyone working from above could easy put their hands on the line wires. British lamps will normally have provision for all four wires. But it is also common with imports to have the change the three way connector block for a 4 way block.
Also industrial lamps i.e. fluorescents don't have the extra connection. Mainly as on suspended ceilings one would feed them from a ceiling rose.