Light stay's on

[snaw]

Hi all.

Changed a light fitting in my bedroom and ran across the following problem, hoping someone can help:

Not sure why but I have two sets of wires in this room. Live/neutral/Earth (Red/Black/green). The spare wire doesn't go anywhere I can see - i.e. only one switch for room, and no other rooms seem affected by this extra wire.

When I connected them all up 2 reds - brown and 2 blacks - blue it blew the fuse.

So tried again with one red - brown and one black - blue and the light stays permanently on.

Anyone point out what I'm doing wrong?

 

[Softus]

One set of conductors is the supply, and the other connects the switch.

You need to identify which set goes to the switch, although if you get it wrong the only problem will be the colour of the insulators being wrong.

If the two cables are 'A' and 'B', then connect them as follows:

A-green to B-green
A-red to B-red
B-black to brown
A-black to blue

This will make the lamp and the switch work without blowing a fuse, but you should ensure that A is the supply and also sleeve the B black conductor in brown.

 

[RF Lighting]

//www.diynot.com/wiki/electrics:blackswlive