Two way intermediate switch wiring

[Harry Bloomfield]

It hasn't been used AS an earth.

Attaching to the earth terminal is a way of safely terminating unused wires - whether the earth terminal itself is connected to earth is another matter.

If that is the case, then the switch which appears in the three later photos has no earth at all - Except when the other switch is screwed into place.

 

[EFLImpudence]

Both switches appear to be earthed although not all CPCs are connected.
Whether they are connected to earth is another matter.

If the yellow is connected to the back box at both of its ends then it can be removed.

 

[Harry Bloomfield]

It seems strange though that the yellow on both switches has been put onto the back box upstairs and then the switch earth downstairs don't you think? And then as you say Harry I don't do understand why there is a yellow/green earth that has been connected to the switch upstairs?

Normal practise, where there are metal switches, is for the switch to be connected via a short earth wire to its metal back box, with the earth wire from the cable being sleeved and also terminated to the back box. All I can say at the moment is that your little diagram of the switch in your first post, is one wire short, whcih would ensure it only worked as a one way switch.

My guess is that someone has picked up some cheap metal faced switches to replace the old plastic ones, then got themselves in a mess doing trying to do the work and abandoned it.

 

[EFLImpudence]

Nicholas -

With the light ON, operate the upstairs switch as slowly as possible - if possible.
Do several times if you need to.

Can you see the light flicker for a split second?

 

[Nicholas Lee]

Hi, yes if I do it really slowly it does go off for a split second. What does that mean?

 

[Taylortwocities]

Ha. We know…

 

[Nicholas Lee]

It not only flickers it actually goes off completely but for a split second.

 

[EFLImpudence]

It shows that the intermediate switch is working but both positions are ON.

I would think, someone tried to wire the intermediate as a two-way but didn't know what they were doing and gave up.


Do this -

Also, get the CPCs (earth wires) from all the cables and connect them all to the switches.

 

[Nicholas Lee]

Ah fantastic, thank you so much for your help. I'll have a go tomorrow when its light. So do I remove the yellow that is being used as the earth? Sorry for all the questions.

 

[Taylortwocities]

Much as I don’t like to guess at things.
Try this:

The “intermediate” switch.
Move the red wire at the top down do it is also in the bottom left with the other red wire.
Move the blue wire down to go in the same terminal as the black.
Put the yellow wirecin the top left terminal.

Downstairs
Put the yellow in the top C terminal and the red and blue in the lower L1 and L2 terminals.
All earths connected up properly and to the front terminals.

See if that works (BAS would absolutely HATE this level of guesswork!

Edit. I see my post has crossed with EFLI. looks like we came to the same conclusion though!

 

[EFLImpudence]

So do I remove the yellow that is being used as the earth? Sorry for all the questions.

Yes, remove both ends before doing anything else.

It is not being used AS an earth. It is just 'parked' in the terminals.

 

[Nicholas Lee]

Fantastic, thank you all very much for your help. I'll have a go tomorrow and let you know. Thanks again.

 

[Risteard]

Normal practise, where there are metal switches, is for the switch to be connected via a short earth wire to its metal back box, with the earth wire from the cable being sleeved and also terminated to the back box. All I can say at the moment is that your little diagram of the switch in your first post, is one wire short, whcih would ensure it only worked as a one way switch.

My guess is that someone has picked up some cheap metal faced switches to replace the old plastic ones, then got themselves in a mess doing trying to do the work and abandoned it.

Very poor practice. It's much better to terminate the cpc at the accessory and then run a link back to the backbox. Then it's not relying on the connection at the back of the backbox.