One Gang two way Switch Replacement for 1970's House

Postby Brannan » Sun Feb 18, 2018 11:31 am

Normally I don 't work on electrics myself but I wanted to fit two new 1 gang 2 way switches to replace a pair of old 1970's switches. When I went to replace them I found the wiring colours and chassis were not quite what I expected.

Switch one has two earth wires terminating in a block and one red and one black wire (sleeved brown) terminating in another block. (The box is plastic)

The existing chassis for both switches has 3 terminals with a pair positioned above the third one. In the separate terminal is a yellow wire and in the topmost of the pair is a blue wire and in the middle terminal (marked COM) there is a red wire. All these three wires are sleeved in brown. 7 wires from two cables.

Switch 2 has the same terminal layout as switch one with yellow in the separate terminal and a blue wire in the upper of the remaining pair and red wire in the middle. All three sleeved brown.

At first I just assumed that the yellow wire here, being separate from the other pair, was the common and that the blue wire was L1 and the red wire is L2, but then I noticed that the middle terminal on the chassis was marked COM. As this seemed wrong and the chassis and wire colour setup was not quite what I was expecting I thought I'd just check.

Can anyone just confirm which is the common and which is L1 and L2 for this chassis please?

I'll try and attach a photo.

Many thanks.
Switch 2.jpg
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Simply Build It

Postby Mr White » Sun Feb 18, 2018 12:39 pm

I have never seen a switch like that before. I would get a multi meter and check which terminal does what. (Another reason you need a multi meter) failing that, since there are only 3 possibilities, I would resort to trial and error, on ONE switch only.
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