Dimmer switch 1 or 2 way?

7 May 2005
Reaction score
United Kingdom
In the above instructions you describe a two way switch - 2 terminals at the bottom and one at the top. My existing light switch has those terminals but only two wires - red & Black (which has a little red cable sleeve moving up and down it). I have bought a one way dimmer switch with an earth and L2 terminal. Can I put the black wire into the earth and red into L2? Or do I need to buy another switch?

Thanks in advance!
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first of al

what instructions above?

why would you want to put the black wire (with red sleave) into the earth when it is not there now?

so long as one wire is in C and the other is in L1 and you put the switch the right way up ( as opposed to upside down) it doesnt matter which goes in C and L1 (red or black) the earth terminal is always for earth nothing else
Skier said:
Or do I need to buy another switch?
No - you need to buy these:

IMPORTANT NOTE - if buying from Amazon, seek confirmation that they are the latest versions.



or http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 261


or http://www.tlc-direct.co.uk/Main_Index/Electricians_Guide_Book/index.html
If it is a normal plastic dimmer switch, it will have "COM and L1" OR "L1 and L2", no earth. If this is the case, then your "earth" terminal is in fact COM (take a closer look). Red/brown goes to COM. Black/blue goes to L1. Earth goes to terminal in back box.
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I have bought a one way dimmer switch with an earth and L2 terminal.

why would a 1G 1W dimmer have just those 2? i was assuming he was somehow confusing earth for common (L1), unless it was a metal switch, but then no common? Maybe i didn't explain it well since i had a bit to drink last night. Apologies.

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