Just a quick question for anyone who could help me on this. I have been trying to fit a new dimmer switch (just a single switch for a single light) but when I took the faceplate off, there were three red wires, two connected to L1 and one connected to L2, with two black wires running into a block (along with a single earth wire). As it stands it works fine (and I took it apart and put it back the same way), but when I tried to fit the dimmer it wouldn't work. I am mystified. It seems like someone had a similar problem (http://www.diynot.com/forums/viewtopic.php?t=16755) but there is no other evidence of any sign of a two way switch, nor indeed of any other wiring going on. The living room light (i.e. the one I want to change) is connected to the stair/landing, if it helps. But to be honest I haven't got a clue.
Even more dimmer switch hassles
- Thread starter SamShep
- Start date
As long as you kept the two reds that where in the same terminal together, I see no reason for it not to work.
As said above, what type of light fitting is it??
As said above, what type of light fitting is it??
You don't make any reference to a COM terminal in the old switch so I take it you don't have one. This means that your old L1 and L2 are the ends of a simple on-off switch.
On a changeover switch there are three terminals marked (usually) L1, L2 and COM. Now for the confusing bit. To use such a switch as a simple on-off, you MUST use COM and one other. That's because this kind of switch flips COM between the other two.
Does your dimmer have three (or more) terminals? If it has three marked COM, L1 and L2 then use COM and one other. I've seen a dimmer with four terminals. It was a bog standard changeover switch with the dimming electronics connected between COM and the fourth one. If you have one of these then use that fourth terminal and one of L1 or L2.
On a changeover switch there are three terminals marked (usually) L1, L2 and COM. Now for the confusing bit. To use such a switch as a simple on-off, you MUST use COM and one other. That's because this kind of switch flips COM between the other two.
Does your dimmer have three (or more) terminals? If it has three marked COM, L1 and L2 then use COM and one other. I've seen a dimmer with four terminals. It was a bog standard changeover switch with the dimming electronics connected between COM and the fourth one. If you have one of these then use that fourth terminal and one of L1 or L2.
The dimmer switch has three terminals, L1, L2 and a wavy line with an arrow through it. This is reflected in the original switch. I wired the new switch identically to the old and nothing happened. The light in question is a three x 60watt sort of chandalier-y light. Is this the problem, as I am utterly lost. Just to recap - the current situiation is: regular switch with three reds - two in L1 and one in L2, two blacks into a box and and earth wire. Help.
Sounds like the dimmer is a 2-way, which is fine, 2-way switches and dimmers can always be used in 1-way applications.
The more common markings for 2-way switches are COM or C, L1 and L2, but you also see L1, L2 & L3 respectively.
For dimmers you'll see COM or C, or L1 for the live in, and usually the squiggle/arrow for output, although it will work just as well with the connections reversed. L2 will be the other dimmed output for 2-way use.
Or it's not a 2-way dimmer but they use the same body, and therefore L2 is not connected to anything. Does the knob have a push operation as well as rotation? If not I'd say to try moving what's in L2 to squiggle/arrow. BUT..
one niggle I'd like to clear up...
The more common markings for 2-way switches are COM or C, L1 and L2, but you also see L1, L2 & L3 respectively.
For dimmers you'll see COM or C, or L1 for the live in, and usually the squiggle/arrow for output, although it will work just as well with the connections reversed. L2 will be the other dimmed output for 2-way use.
Or it's not a 2-way dimmer but they use the same body, and therefore L2 is not connected to anything. Does the knob have a push operation as well as rotation? If not I'd say to try moving what's in L2 to squiggle/arrow. BUT..
one niggle I'd like to clear up...
In what way, exactly?You said:
C
confidentincompetent
Just to confuse evry1 I had similar prob sveral yrs ago, Im a decorator and was asked JUST pop this dimmer on for us 
after lots of bad language I realised that lighting loops were in all the switches NOT in ceiling roses 
and getting light to work shut off landing lights or vice a versa. Cant remember how I did it but its still working ok. Seems whole estate is wired like this They are about 20yrs old. Not seen this b4 is it normal to have lighting loop at the switch???
after lots of bad language I realised that lighting loops were in all the switches NOT in ceiling roses and getting light to work shut off landing lights or vice a versa. Cant remember how I did it but its still working ok. Seems whole estate is wired like this They are about 20yrs old. Not seen this b4 is it normal to have lighting loop at the switch???
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