Oops, what have I done? (light switches)

[WillyWarbux]

I had the electricians out yesterday to check my new house's wiring. All good apart from some minor issues.

Today I noticed that the light switch in the bedroom was turning the lights on in the up position and off on the down position. So I powered off, unscrewed the switch off the wall and had a look to see if I could just turn the whole thing upside down without touching the wiring.

There was a red going into COM, a red going in to L1 and a red going into L2. (There's 1 ceiling light in the room). Unfortunately one of the cables snapped when I tried to (gently) twist the whole plate around.

I took the whole thing off and swapped the L cables around, thinking that if something's wrong with that, I'll know shortly and will just swap them back again and forget about it.

That did the job I thought, the light now went on in the down position. But...

The rest of the lights in the circuit now don't switch on. Oops.

So I swapped the L cables back to how they were originally and to my horror, found that the other lights still aren't switching on.

What have I done?

Cheers,
-Will

 

[EFLImpudence]

I would say that both L wires should be in the same terminal, L1 or L2 depending which way up the switch is.
Or that there were two in COM.

Are you sure they were in separate terminals?

 

[WillyWarbux]

I should also say that's there's only 1 light switch controlling the 1 ceiling light. And I thought that seemed strange that there was an L1 and L2 wire.

I never like to say I'm 100% sure that there was a wire in L1 and L2 when I opened it up. But I'm 95% sure.

Maybe I'll go and bash both the Ls into 1 terminal to see what happens.

 

[EFLImpudence]

Yes, if it still doesn't work properly, swap the COM wire with one of the others until it does.

I presume you have two three black wires in a connector block in the wall.

 

[WillyWarbux]

No idea about the black wires. Just 3 red ones coming into that switch and 1 earth.

So it must be my ageing eye-sight, but I could have sworn the L1 and L2 were both in use when I first opened the unit up. I have now put both L wires into L1 and the downstairs lighting is now working again! Thanks!

Although, that particular ceiling light still turns ON when the switch is on the up position. I'll just get the electrician to fix it when he returns.

 

[JP_]

I spent ages trying to get my lights to work the other day after changing a ceiling rose.
But after close examination of the photo I took before, I worked it out.
Always take a photo before unplugging or dismantling stuff - that's my no.1 DIY rule. Makes it easier to fix, and if nothing works, you can show before and after photos here!

 

[EFLImpudence]

No idea about the black wires. Just 3 red ones coming into that switch and 1 earth.

Ok. They must be somewhere.

I have now put both L wires into L1 and the downstairs lighting is now working again! Thanks!

Good.

Although, that particular ceiling light still turns ON when the switch is on the up position.

Just move the two wires from L1 to L2.

 

[SFK]

Willy
[If you wish] to turn the operation of the switch upside down from what you have now (without rotating the switch itself), move the two L wires from L1, and put them both into L2. [edited]
SFK

 

[WillyWarbux]

I spent ages trying to get my lights to work the other day after changing a ceiling rose.
But after close examination of the photo I took before, I worked it out.
Always take a photo before unplugging or dismantling stuff - that's my no.1 DIY rule. Makes it easier to fix, and if nothing works, you can show before and after photos here!

Yeah that's something I've done in the past, this time I didn't have my phone to hand so I drew a little 'C' '1' and '2' on the wires as I saw them heading towards their respective terminals. But it was pretty dark- so maybe that '2' wire at the last moment darted into the L1 terminal out of view. Good tip though, thanks.

 

[WillyWarbux]

Willy
To turn the switch upside down from what you have now, move the two L wires from L1, and put them both into L2.
SFK

Wouldn't it be 1 or the other?

 

[SFK]

Willy,
You said that you "have now put both L wires into L1... and the light works".

Because of the design of the internal switch mechanism, if you now change it by putting "both L wires into L2" then the operation of the light switch reverses. So if switch was sticking out at top before when ON, after moving any wires in L1 to L2, the switch will then be pushed in at top when ON.
SFK

 

[WillyWarbux]

Willy,
You said that you "have now put both L wires into L1... and the light works".

Because of the design of the internal switch mechanism, if you now change it by puttng "both L wires into L2" then the operation of the light switch reverses. So if switch was sticking out at top before when ON it will now be pushed in at top when ON.
SFK

I totally missed the "To" at the start of your previous message! Sorry mate, cheers.

 

[SFK]

Willy,
Not a problem - I have edited and hopefully improved my text. :>
And note that EFL suggested the idea before me saying: "Just move the two wires from L1 to L2".
SFK