Wiring Colours

[MikeGP]

Hello,
I am replacing a dimmer switch in my house. In the switch there are the following wires: red (connected), yellow (connected), and blue (not connected). Could someone please advise what each is as, in the switch, I can not see any lettering saying which pole is which. I am attaching a photo.

 

[westward10]

Was the blue definitely not connected and didn't break off when you removed switch. Is it two way switching whereby there are two switches controlling one light.

 

[littlespark]

I’d say red is permanent live, yellow is the switched live. Without testing properly, the blue could be a neutral, or just may not be connected at either end. Or as westy suggests, it’s part of a 2 way circuit.

just be certain you’ve got the power off.

 

[MikeGP]

Hi Guys, Thanks for replying. The blue was definitely disconnected as it was laid across the back of the box. The switch is a single switch to a single ceiling light fittting.

 

[westward10]

Doesn't really matter which way you connect the red and yellow at the new switch. The blue should be made safe by putting it into a connector.

 

[7029 dave]

I’d say red is permanent live, yellow is the switched live. Without testing properly, the blue could be a neutral, or just may not be connected at either end. Or as westy suggests, it’s part of a 2 way circuit.

just be certain you’ve got the power off.

That would be my configuration. On rewires I used red perm, yellow and blue as S/L if needed.

 

[MikeGP]

Thank you so much guys. ?

 

[loz2754]

Just be aware that if the dimmer you are fitting is metal, it will need to be connected to earth. Is there a green and yellow wire in the switch box?

 

[Zerax]

And when you remake the terminations... you don't want any copper exposed... so in your pic, they should look like the red conductor not the yellow one.

 

[7029 dave]

And when you remake the terminations... you don't want any copper exposed... so in your pic, they should look like the red conductor not the yellow one.

Yeah no shiners.

 

[MikeGP]

No problem guys - all understood and, no, the box is plastic. The yellow wire was actually fully home - it just came a bit adrift when I turned the box to take the photo. I will make sure it is tight home. Thanks again.