Where do the wires go? (1x light + 2x Switches) + (1x Light

[Relievo]

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?

Thank you for your help in advance

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.

 

[EFLImpudence]

It's not really possible to tell but we can have a guess.

Do you have a multimeter?


If the red and black on the right were twisted together like that, it would indicate to me that they are not used.
What about the CPCs(earths) in the cables without?

 

[PrenticeBoyofDerry]

You will need to identify which cables go to and from the switch.
One will be red and one will be black the red will go into the live loop, this is not connected directly to the light fitting but is terminated in a connector all of it's own or the loop-in supplied on the fitting. Then the returning black should be identified as the switch live and marked accordingly, by use of red sleeve or red markings.
This black would then go to the live side of the fitting.
The three remaining blacks would then be terminated to the neutral of the fitting, and all earths at the earth terminal.

This would be the normal set up, when looping in at the fitting, if you have a switch on this part of circuit that turns more than one light on, this could differ.

I suggest you use and approved voltage indicator and continuity tester to assure you have ID'ed and made the connections correctly before energizing.

The diagram suggests that you only have one earth cable coming in to the fitting, this would need to be checked, as it would seem you have purchased a class 1 fitting which requires a path to earth. It could be that the earths have been cut back and still accessible within the sheaths of the cables.
This would mean you will need to confirm that you have a suitable path to earth.