Need help figuring out two way lighting circuit

[plumma72]

Hello,

I have two, two gang, two way light switches, one upstairs and one downstairs, I have figured out one side, but the side that controls the light downstairs from upstairs and downstairs, I can't figue out what's going on.

Upstairs, it's just the termination of the strapper three core cable, but downstairs is a mystery.

As well as the strapper cable there's three twin and earth, but I can't make head nor tail of what is happening.

The lighting rose doesn't have a loop in it, just the live/neutral, so I suspect there's a juncton box somewhere.

If I knew where the cables went then it would help alot, but I can't figure out which one is a live feed or goes to the lamp.

Hopefully someone can help me figure it out, thanks.

 

[endecotp]

Does it work?

 

[pete01]

Did it work before? Have you changed the wiring?

Looks like you have feed in, feed out, supply to light and the 3 core at the downstairs sw.

I think.....

Have you got an actual picture of the switch wiring?

 

[plumma72]

It does work, I haven't touched anything, I will try and get a picture but it's a bit tight in there with a jungle of wires.

 

[EFLImpudence]

...

 

[blup]

If it does work there will a JB somewhere which will clarify the circuit.

 

[ericmark]

The two standard methods to wire two-way switches.

 

[EFLImpudence]

Eric; I have said it before but those really are crap diagrams.


Perhaps a DIYer tried to follow them and ended up with what Plumma72 has.

 

[ericmark]

The CAD program I did them on, I no longer have, so can't repeat it. I prefer the second method, as it will work with some master/slave switches where the com is replaced with the S-Link.

My multi-switch two-way switching uses a relay. The relay looks for a change of state, not simply open or closed circuit, so also my phone or voice commands can switch on/off.

At what point will we need wiring diagrams for a house? I have one 4 gang switch plate with three circuits, downstairs lights, upstairs lights and extra low voltage. And the central heating, well that does need a diagram.

 

[AndyPRK]

I was wondering if the American method had been used, where the neutral was used at the switches! Lets hope not.

 

[EFLImpudence]

I was wondering if the American method had been used, where the neutral was used at the switches! Lets hope not.

How do they do that?

 

[Jurassicspark]

Hopefully someone can help me figure it out, thanks.

They commonly say, if it works as it should then it’s better to leave it alone.

 

[Jurassicspark]

I was wondering if the American method had been used, where the neutral was used at the switches! Let’s hope not.

Live in L1 and neutral into L2 with switched live into com?

Based on the OP’s drawing it doesn’t look like that.

However, they aren’t uncommon with the old type of switches.