1 bulb 3 switches diagram (intermediate switch wiring)

This shows two ways of wiring multi-way light switching, making use of an intermediate switch. It also shows a third way shared online by JrElectricSchool, which doesn't work properly.

What it doesn't show (as I've only found it online after editing the video) is another working option which is sort of a hybrid of the two. The twin-and-earth switching pinout can be used with triple-and-earth cable, using the third core as the neutral conductor. This requires the whole supply (L-E-N) to be taken to the first switch enclosure in T+E, the inter-switch-connections L1-L2-E-N made in 3+E cable and the final (and only) connection to the light fitting taken from the last switch in the chain, as SL-E-N once again in T+E. Correct sleeving of line and neutral conductors would be essential in this scenario as there's the potential to switch a short-circuit if conductors aren't correctly identified.

INDEX
0:00 Index
0:10 Introduction: multi-way light switching
0:23 The three-core-and-earth method
4:01 The twin-and-earth method
6:24 Garbage on social media and so-called training websites
7:00 The wrong wiring method

[pickholder]

Happy Christmas - great video. You are 100% correct.

[sparkyprojects]

I always like it so that all switches on a lighting circuit in the same position means the light is off, handy if you just want to change a lampholder without isolating at the board

[lewi]

Does it matter which way round the L1 and L2 from the two-way switch go into the intermediate switch as long as they both go into either L1 or L2?

[zaprodk]

That's weird. The video is interlaced?

[proluxelectronics]

That why I don't play with domestic wiring, far too complicated. Just use an FPGA...🤣🤣, have a happy new year.