Old switch to new style!?!

[Marvin Struggler]

Hi there

I am trying to replace an old light switch for a dimmer switch.

The switch is a single and is for one light only although the light has another switch for it on the other side of the room.

The old wiring system has :

Cable A - Yellow, Red, Blue, Earth

Cable B - Red, Black, Earth

So the wiring goes to the socket thus:

L1 - Yellow (from cable A)

L2 - Red (from cable A) - Red (from cable B)

L3 - Blue (from cable A) - Black (from cable B)

I clearly have the Earths sorted but I am a tad confused how to re-locate the wiring to the new socket which has the following labels for the wires:

~ (Load)

S (Slave)

Downward arrow (Live)

Can anyone explain how the wiring should be distributed to the new socket.

Many thanks for your time and consideration.

Martin

[Cejay]

Hi Marvin What you describe seems like a standard 2way light so first you need to ensure the new switch you have purchased is to replace a 2way switch (some are only 1 way)

It should have 3 connections (not including the earth terminal) These can be marked in different ways but are normally along the lines of L1 L2 Comm or L1 L2 L3

You state Load Slave & Live (must be a foreign switch)

You could try the following..(TURN OFF POWER)

connect cable1 yellow to LIVE connect cable 1 red and cable2 red to LOAD connect cable 1 blue and cable2 black to SLAVE

Try the switch & the 2 way operation with the switch at the other side of the room.

Failing this FYI the red/black cable 2 is the switch wire from the light (hopefully) to check this just short them together and apply power and the light will come on permanently.

The 3core cable 2 is the strapper cable to the other switch.

The way the system works is simple ;; the 3 wires of cable 2 join the 2 switches L1-L1 L2-L2 L3-L3 or more commonly COM L1 L2.

Each colour going to the same pin on each of the 2 switches.

The switch wire from the light (cable 1) now connects (1 wire in L2 & the other in L3) along with the blue & black from cable 2.

To simplify identification if you look at the rear of the old switch the cable connections form a triangle IE 1 top centre & 2 bottom left & right. The one at the top centre is the Comm or L1 terminal and switches between the bottom 2 terminals L1 & L2. (L2 L3)

HTH Jon

[Marvin Struggler]

Hi Jon

Many thanks for the reply. This is the switch that I have purchased (there is a PDF file showing instructions and labelling):

Although the switch says that it is 1-way it says you are abot to use it with 2-way if used with a Slave Unit - needless to say I don't know what a Slave Unit is :)

I have had a look and cant find the 2-way Single gang option so I assume I will have to get a Slave Unit and fit it.

Many thanks again for your help Jon.

Martin

[Cejay]

Hi Martin Yes you have a touch switch dimmer; whilst one does exist (or did last year when I fitted 1) that is 2 way most are 1 way and use a SLAVE switch to achieve 2way operation. This is done electronically rather than mechanically so your second switch is useless. The good news is that you can still use your existing wiring for the slave switch. For now just wire your cable 2 Red/Black into the new dimmer; Red to LIVE and Black to LOAD do not connect cable 1 or anything to the SLAVE terminal.

This will allow the switch to work but your second switch will not. When you get the slave switch then use the cable 2 (red/yellow/blue) to connect it as per the instructions supplied..

HTH Jon

[Phil]

TLC sell a slave unit, but you need to check if they are compatible with your screwfix master

A diagram of the standard 2-way switching, which you seem to have, is described in the FAQ

[Marvin Struggler]

Many thanks for all of the help guys - having waited until it was daytime, the football wasn't on and I was sober the switch is now, finally, working.

Again, many thanks

Marv