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Replacing existing switches with smart switch

Postby DTMHibbert » Thu Dec 16, 2021 8:49 pm

Hi Everyone - first time poster here

I need some help with smart light switches. I’ve had a look at the back of my current standard switch which looks like the image attached

This is a 2 gang socket which controls ceiling lights and lights under the wall cupboards in a kitchen. We want to keep the same functionality (two switches)

From what I see/ understand in the picture

COM - this is the Live cable - there appears to be smaller piece of wire connecting both “COM” terminals but also an individual wire feeding straight into the terminals.

Neutral (blue) - this isn’t connected but is there so I assume I could buy either smart switch type (requires neutral and does not require neutral) there appears to be 4 wires in a terminal block why 4?

There are two L1 terminals at the bottom which I believe feeds the lights themselves.

If I were to buy the switch attached, how would I wire this up?

Thanks everyone
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Simply Build It

Postby Mr White » Fri Dec 17, 2021 8:13 am

Your understanding and observations are quite good.
However, there are two questions that you ask that require further investigation before you can proceed.

1) Why are there so many blue wires? (Also are they neutral, probably, but are they?)

2) Why is there a "smaller piece of wire" (Link) between both Com terminals. (It is unusual as you also have another wire in each terminal.)

Without the answers to these questions, it is not possible to give you the correct information, so I can only suggest you get an electrician in to answer these questions and change the switch for you.

I would also suggest with the electricity off, you measure from the back of the metal back box to the surface of the wall. (I note the box has been sunk in too far, hence measure to the surface of the wall) The reason is the switch you mention requires a back box depth of at least 35mm (It is another thing that can not be investigated remotely.)

Are you aware that you can get 2 gang versions of the smart switch you show? (The one you show is 3 gang, and as such has 3 buttons, where as you only require 2 buttons.)
Mr White
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