DIY Doctor UK DIY Forums

Hi

I wish to be able to switch a lamp on the upstairs landing from three different positions, it is currently run on two way 1G switchs.
The switched live twin & earth cable comes in at top of stairs plus existing three core to switch at bottom of stairs, wired (twin red to L1 & black L2) and threecore (yellow L1, Blue L2, Red com).
Having run a new three core cable to the other end of the landing and connected new switch like for like with the existing threecore cable at the switch on the top of stairs. I can get all switches to switch on and off seperatly, however if any one switch is left in the on position the remaining two will not function.
This has got me beat i have to admit!

What wiring connections are required to run three way switching?

Regards

Paul

Hi Paul, great explanation, unfortunately not going to work the way you have it.
you need a 4 terminal 'intermediate switch', it needs 2 twin/e cables and basically they are used to break the two looped cores in your 3 core ie not the common red.( this is a bit like describing a spiral staircase with your hands tied behind your back sorry).
If you can get at the 3core between switches & fit a 6term j.box you can take two twins to it from new switch position, cut 3 core ,connect red back together in 1 term all earths in another term. then yel& blu to one twin and other yel/blu to other twin, at new switch connect 1 twin to each pair of terms, there is usually a drawing with or on switch, best wishes SPARX

Hi SPARX

As the saying says, a picture speaks a thousand words!

The switches in question are chrome finish, therefore limited in there range, i Have checked the catalogues, cant find a 4 term version.

The wiring is all accessable from the loft, so junction box could be the way forward, however, can you clarify:
- am i right in saying the two twin replace the new three core cable?
- you say at new switch each twin goes to a pair of terms, do i take it that a four term switch is still required?
- if so is there any alternitive way of doing it with three term switches.

Regards
Paul

Sorry Paul, yes you do need an 'intermediate ' switch which has 4 terminals, there is no other way otherwise they wouldn't make them!
I am sure in 'projects' there must be a drawing,
Leave 3 core and cut in with J.B. the common rejoins & the 2( now 4) ends go to the 4 ends of the 2 X2cores. good luck,SPARX