Dimmer wiring - how to wire the ceiling rose? Ask questions and find answers to many subjects relating to electrics and electrical work

[Jokerman101]

My friend had two light fittings (4 light bars) that you could dim fitted and has changed her mind and wants a ceiling rose fitting instead. My friends husband changed it and wired all of the live to live, all of the neutral to neutral and the switch to the switch in the ceiling rose (four live and three neutral). Whilst one light can be switched on and off the other is continuously on, this ceiling rose has only one cable. How do you wire the ceiling rose?

[ericmark]

In the UK we use a ceiling rose which as well as earth has three Live connections.
1 Normally a twin connection switched Line edge of strip and connects to lamp.
2 Normally three connections permanent Line not normally connected to lamp unless an emergency fitting is used centre of strip.
3 Normally three connections Neutral edge of strip and connects to lamp.

Into these often three cables one with permanent Line and Neutral from previous ceiling rose in radial, the next cable again permanent Line and Neutral to next ceiling rose in radial, and finally we have a cable which goes to the switch with a permanent Line and switched Line.

The latter cable is often the same type as other two and in theroy it should have a sleeve or tape on the black or blue wire to show it's not neutral but the switched Line. However it often falls off and is the main cause of problems with DIY fitting changes.

Some times it has a second branch either to second lamp in same room so takes the switched line or a spur to another room so used permanent line, also there will be one at end or radial which only has two cables.

Pre brown and blue cables there was twin and earth with two red cores but never seen twin and earth with two brown cores so in the main the light has two black or two blue wires feeding it the reds or browns rarely feed direct to lamp.

[Jokerman101]

Thanks for that, I thought that was the case but was unsure due to there being four cables. After more investigation, I have discovered that there are four lights to this circuit (arranged in a T formation). That means the ceiling rose with four cables (center of the T formation) has 1 cable from the first light in the circuit, cable 2 must go to the next light, cable 3 must going to the end light (hence only the one cable at the ceiling rose) and the 4th must be the switch cable. Am I right in assuming that as my friend has wired in all of the lives together, this is the reason that the light with one cable is always on? If this is the case do I connect the live cable from this light to the switch terminal so that this light is switched on and off? As he did not label any of the wire, I will have to isolate one at a time to find out which cable is which (oh joy).

[ericmark]

I was banned from this forum for trying to guide some one into how to detect the switch wire without using meters for a year. Some one said my method was dangerous as it could be miss understood. It is just too easy to either miss something out with instructions or for some one to miss something out reading them so after being banned once sorry I am not doing it again.