3 wires in a dimmer switch

[peterinscotland]

I have a plastic dimmer switch arranged with a vertical on/off switch on the left and a vertical rolling dimmer on the right. There are no other switches connected to the light fitting it controls (a three-way spotlight using R63 screw-fitting bulbs).

I want to remove the dimmer facility because
a) I never use it - if I want soft lighting we have table lamps
b) It buzzes a little if you use it on anything other than full brightness (always has and I've had the house for nearly 17 years) - this is another reason I never use it
c) It has a little fuse which blows every time a bulb blows
d) I'm told you can't use low energy bulbs with a dimmer switch

So, I had a look inside and it has four terminals arranged thus:

Variable Load ................................ L 1 ....... L2
.....................................................................
.....................................................................
.....................................................................
..................................................... Fixed Load


Variable Load has two red wires in it, and L2 has one red wire in it. The L1 and Fixed Load terminals are empty.

First question: Why are there two wires in Variable Load, considering there are no other switches connected to the light fitting?

Second question: Can I just move the two wires from Variable Load to Fixed Load and achieve my desired result of (a) disabling the dimmer switch and (b) not needing to replace the little fuse every time I replace a bulb?

Equally, can I replace the whole thing with an ordinary plastic light switch, putting the two wires (that are together) in one side and the other wire in the other side?

Kind regards

Peter

[Steve]

Do you have a picture of this arrangement? front and back of the switch unit?

[securespark]

peterinscotland wrote:

c) It has a little fuse which blows every time a bulb blows

Good job! Modern dimmers do not have these and I am forever replacing dimmers toasted because the lamp failed, and there was no fuse to protect it...

Do you have more than one light switched by this arrangement?

If so, the other wire may control the other light. On the other hand, it may be that the live feeds have been put in the variable load terminal.

Either way, you can replace the switch.

But you need a multimeter to find out which wire is which.

If the two reds are a live in to and out of the switch, put these in the Common of a 1G1W switch. Then put the other wire in the L1 terminal.

If the live feed is the single cable, fit this to the common of one side of a 2G switch, and loop across to the other common.

Then place one each of the others in the L1 terminals of the 2G switch. Or, if you want to switch them together on one switch, leave them together in the L1 of a 1G switch.

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"

[peterinscotland]

Front


Back


Wall connections


The only lights on this dimmer - there are no other switches on these lights either

[securespark]

In that case, I suspect that the two wires are the feed in & out of the switch & the single one is the switchwire. Put the two to common & the single to L1 of a 1G1W switch.

You have no cpc present at the switch position, and unless the conduit is effectively earthed, that means potential danger.

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"

[Steve]

Where do the white wires go?

[securespark]

To a switch back to back, it seems.

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"

[peterinscotland]

I'm not sure if this is what you mean, but there is a switch on the other side of the wall, which is a double, one half of which is a two way controlling the top of the stairs; the switch at the top of the stairs is a single which only controls the light at the top.

The house is approximately 40 years old and was a council house.

[securespark]

This looks likely. The whites are probably strappers (they link the switch at the bottom with the switch at the top), and I can see now that one of the reds from the dimmer goes through too.

So, there is a feed to the common of the landing two way/hall switch at the bottom of the stairs and a switchwire to the landing light connected to the common at the top switch, with the white wires linking the two.

Thinking about that earth...If you apply a Multimeter set to 400V across the terminal with two wires in and stick the other probe into the lug (where the fixing screw goes, how many V do you get?

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"