From 2-gang to 1-gang light switch

[Stavros.]

Hello

I thought I had an easy task but the solution escapes me!

So, I’ve got this 1-way 2-gang dimmer switch controlling my kitchen spotlights (half by one dimmer, half by the other), and I want to replace it with a 1-gang so I can control them all at once. I don’t have access to the ceiling rose or box but I attach a drawing and two photos of the current set up (2-gang), which works fine.

Both red cables measure 240V, the black 2.7V, the blue 2.1V and the yellow 0V.
Could you please advise which configuration I should use to turn it into 1-gang?

(I also attach the new switch diagrammatic instructions)

Many thanks

Stavros


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[333rocky333]

You should check that your new dimmer is suitable to dim 15 lights, total wattage should be considered and with Led there is often also a limit to the number of lamps, regardless of the wattage being in range

 

[securespark]

Are there more wires attached to that switch?

The diagram suggests that the switch needs a neutral connection. If this is the case, that only leaves 1 feed conductor and 1 switched conductor. In other words only enough for one switch.

 

[Stavros.]

You should check that your new dimmer is suitable to dim 15 lights, total wattage should be considered and with Led there is often also a limit to the number of lamps, regardless of the wattage being in range

Thanks - I’m ok I’m terms of total Watts (but not sure how I’d find out about total number - they are LED indeed)

 

[Stavros.]

Are there more wires attached to that switch?

The diagram suggests that the switch needs a neutral connection. If this is the case, that only leaves 1 feed conductor and 1 switched conductor. In other words only enough for one switch.

No, there are no more wires attached; there’s no neutral (or ground) on the existing switch.

But the new switch requires a neutral (which makes me scratch my head) and a ground (so I’ve added a short cable from the G of new switch to the back box ground point).

 

[securespark]

Sorry, it sounds like I was mixing up the old switch and the new wiring diagram.

 

[Stavros.]

Apparently this is a quite common problem as most smart switches require a neutral but most UK wiring configurations don't bring the neutral wire to the switch. I'm wondering... if I pull down one of the spots and connect the neutral to the line (e.g. black) and then at the switch connect the line (black) to N - would that work?

 

[GarethW]

What's that yellow wire on the left doing, is it connected to anything ? If not you could attach it to a neutral and tape bothe ends with blue pvc tape.

 

[Stavros.]

What's that yellow wire on the left doing, is it connected to anything ? If not you could attach it to a neutral and tape bothe ends with blue pvc tape.

I tried that but no luck. I think it's another ground (no idea why there would be two in the same cable).

 

[securespark]

Are you sure?
Yellow is a live conductor, not an earth.
It may be connected to earth at one end if it's a spare.
If this is the case, disconnect it from the earth terminal and it can be repurposed as a neutral.

 

[Stavros.]

Of course I’m not sure - I hardly know what I’m doing!

However, I tried this configuration (green/orange line is that yellow) and both circuits were permanently off