Wiring intermediate switch

[Andy up north]

Hi
looking for a bit of hopefully simple advice.
I am replacing an existing intermediate light switch. As it suggests, it is the central of 3 switches working 2 upstairs lights. First switch by bedroom, second switch this one, third switch downstairs.
The existing switch is as follows:

It is difficult to see but L2 is marked in between the top 2 connections. I can't see an L1 anywhere.

This is my new switch:

So my question is how should I wire up the replacement switch?
I have looked on line and seen examples of the 'in' L and N into the top L1 and L2, and equally into L1 and L1.

thanks for advice.

 

[Deleted account]

Basically all the conductor are line conductors. The black are not neutrals, so two line conductors from one cable go in L1 &L2 top or bottom. And the other two line conductors go in the other terminations, but....

.... big disclaimer. That’s if the current two way is correctly wired. And it is an intermediate switch. looks like one.

 

[Andy up north]

Thank you
so, its cable 1, red to top L1, black to top L2, and cable 2 red to bottom L1 and black to bottom L2. in effect I am matching the current wiring layout.

That is how I read it from some research.

The bit that threw me was that it wasn't clear that this was how the existing switch is wired as, if we assume both top connections are L2, since the L2 marking is plum in the middle of the 2 connections it looks like cable 1 is red to top left L2 and black to top right L2.

Andy

 

[Deleted account]

Lots of assumptions. Without testing that’s all you can do, but if the Assumptions are wrong. Bang!

 

[littlespark]

Lots of assumptions. Without testing that’s all you can do, but if the Assumptions are wrong. Bang!

You’re not going to get a bang from an intermediate.

red and black from one t&e in L1 and L2 at the top, red and black from other into L1 L2 at the bottom.

both cpcs together onto metal back box or into connector if plastic.

Don’t put the little screw cover caps on until you’ve made sure it’s working correctly

 

[7029 dave]

OP, is that metal back box earthed.

 

[Andy up north]

thank you, that was my understanding that if I wired an intermediate incorrectly it might not work correctly but wouldn't 'bang'.
I will swap tomorrow and report back.

 

[MDJ]

GASP!!!!!

 

[Andy up north]

Thanks everyone.
All wired up and working perfectly, and yes metal backbox earthed.

cheers
Andy

 

[FatAlan]

You can put the little screw cover caps on now ?

 

[Andy up north]

Do you recommend the left or right first as wouldn't want to get it wrong at this late stage ?

 

[littlespark]

Start with the left, but make sure the slots on the fixing screws are horizontal before covering them up. ??

 

[FatAlan]

Nah, screw slots should be vertical to allow any condensation to drain away. ?

 

[telectrix]

Nah, screw slots should be vertical to allow any condensation to drain away. ?

but won't that allow electrickery to escape through gravity?