Wiring 3-gang light switch with one 2-way

[mr_ric74]

Hello all!

I am replacing a 3-gang light switch but foolishly didn't take a picture of the wiring before I removed the old face plate!
I am now struggling with the wiring, so after some help, please.

The new plate is 4-gang but I am only using the first 3 as I couldn't get a 3-gang when I was in B&Q.

The first switch is one-way and for the living room and I have the brown wire (I am assuming this is the live?) going into COM and the grey wire (neutral?) going into L1.

The second switch is two-way and does the landing. This has a brown wire going from the COM on switch one to the COM on the second switch. I then have a black wire, which I presume is the switched live, going into L2.

I then have the other brown wire going into COM on the third switch and the grey wire going into L1.

The issue I have is that switch 2 and 3 work but switch 1 doesn't work and there is another black wire that I don't know where to put. This wire is definitely to do with the living room lights but wherever I put it it trips the breaker. What I am I doing wrong, please?

Please see pic attached.

TIA.

 

[terryplumb]

Switch 2 is two way and you told us it works ,does the other remote switch that controls the same light fitting also work ? That would be odd as switch two only has two wires connected to it.
What trips ,RCD,RCBO,or MCB when connecting the "loose" black wire ?
Show us a picture of the outer sheaths where the grey/ brown/ black conductors come from.

 

[mr_ric74]

Thanks Terry. Sorry that was the wrong picture. This is how it looks now with switch 2 working upstairs and downstairs.
And it's the RCBO that trips

 

[mr_ric74]

I will be getting a metal back box as well next time I am out

 

[terryplumb]

I am confused now ! Have you changed the picture in your original post ?
Your original text makes no sense now .

 

[mr_ric74]

Yes so I have moved the grey wire from L1 in switch 1 to L1 is switch 2 which makes the landing light function correctly at both switches.
I have restored the original photo to avoid confusion.
The new photo is what I have just done to see if I could get the landing light to work but obviously that leaves switch one with nothing in L1

 

[EFLImpudence]

A picture of the landing light switch wiring would be useful.

 

[ericmark]

Two get a switch with 1 to 4 gangs the easy way is the grid switch, I used one so I could combine a socket, fuse holder and switch, I used Screwfix LAP range, but there are loads of grid switches, so you can mix and match, and for a double socket back box you have 4 modules one can be a blank.

As to the wiring, two way switches normally used triple and earth between master and slave, and two core master to lamp, the two switches master and slave have same colour wires in each terminal in the main, and the master has the two core as well in the 1 (1 way) and 2 so one ends up with only a wire from the slave in Com, the Com wire is the important one, the other wires swapping them does not really matter.

So in the main you can look at the other switch of the pair to work out how to wire it, assuming this

wired diagram has been used, there is another method

but one ends up with a connector block in the master, not first is method normally used.

It seems you have two triple and earth cables, I would have expected a triple and two twin and earth cables, however since two triple one with likely work the two on/off lights and the other the two way lamp, if it were me I would put all wires in a block connector to make safe,

then select one cable connect all three wires together and see what lights, one now know which cable is which, for the two way copy the connections in other switch of pair, for on/off I would use a meter to find line in, but two coms connected together with short link, and one has a one in three chance of getting it right first time, 2 is not used for on/off, and SP not used with any switch, so three attempts and it should work.

 

[mr_ric74]

Thanks I have sorted it now. I put the 2-way on the 3rd switch instead so it wasn't connected to the other 2 switches at all and it all seems to be fine.

 

[EFLImpudence]

Very good.

However, it will have been more to do with which wires you used for the two-way rather than which switch you put them in