In my case I have one light switch that controls one light bulb. There is 3 bus bars, one 2-slot and the other two 3-slots. The current wiring would basically be like this:
Disclaimer: I am not a qualified electrician. I’m self-taught and this is actually only for my own notes.
Remember, turn off the power anytime you are touching the wiring, I also recommend telling people in the accommodation that you’ll be turning off the power and not to turn it on without informing you.
Power
Live IN (commonly brown wire) to a bus bar (lets label this live bus bar)
Neutral IN (commonly blue wire) to a bus bar (lets label this neutral bus bar)
Ground/Earth (commonly green and yellow striped wire IN to the ground/earth bus bar.
(this is passing the live, neutral & ground to the next room)
Live OUT (commonly brown wire) to the live bus bar
Neutral OUT (commonly blue wire) to the neutral bus bar
Ground/Earth (commonly green and yellow striped wire IN to the ground/earth bus bar.
This means we have 1 slot left on both the live & neutral bus bars
Light Switch
One end connecting to the 2-slot bus bar and the other end connecting to the live bus bar.
Light Bulb
Live (commonly brown wire) (positive end of the light bulb) connects to the 2-slot bus bar (switch).
Neutral (commonly blue wire) (negative end of the light bulb) connects to the neutral bus bar.
Now we should have filled all slots on the 2-slot and both 3-slot bus bars. We’ve basically connected power to the live and neutral bus bars (and the ground/earth connected too).
If unsure which cables are Live and neutral in/out, you should disconnect them and using a multi-metre (set to AC) probe a set of brown and blue wires till you get the 240v, this would be your IN. You can also switch on the light switch and you’ll tell which lines are your switch wires.
Links & References
Wiring Diagram For a One Way Lighting Circuit Using the 3 Plate Method – Connections Explained – YouTube
https://www.youtube.com/watch?v=fixa_1jp55c
Electrical Wiring Colours – A Complete Guide | RS
https://uk.rs-online.com/web/content/discovery/ideas-and-advice/wiring-colours-guide