The ballast in one of our oldest florescent lights finally died, so I thought it would be a good opportunity to replace it.
The wiring was a bit of a jumble (I should have taken a photograph).
We have a main light, with 2 switches (upstairs and downstairs),
then next to that, a second smaller light with a separate switch to operate that independently, which looks like it is wired to the main first light. But I'm not sure how to attach it.
I understand the 3 red wires all go together, and the three black?
But where do the 3rd set of black and red go? 🙁 …I'm guessing they might be for the second light/switch?
The picture below is of the wires which were attached to the main light, and below that is the connections to the new florescent light.
Best Answer
You need to connect the switched live to the brown wire in the new fitting and the neutral to the blue wire. The neutral will be one of the black wires. The switched live may be red, or it might be a black wire in one for the T&E cables (though it should have red tape or sleeving on it if it is...).
You might need look at the switches to try and figure out which cable is which. A typical arrangement for two-way switching is shown here (I've linked rather than inline-display the image for copyright reasons).
I'd hazard a guess that the two cables with the red and black joined are the feed coming in and going out to the next fitting on the circuit - but don't take my word for that, please check that for yourself.