Dimmer Switch to replace normal switch (1 way)

[coops1975]

Hi

Currently I have

3 Black wires within a T Block

2 Red wires feed into L1
1 Red wire into the Com

1 Earth wired to metal box in recess.

No wire in L2 (due to the 2 way switch being used as one way)

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What I plan to do (if this is right) --- On the Dimmer Switch

Leave the 3 black wires alone within the T block

Move the 2 Red wires into the terminal marked via a ~> type symbol

Move the 1 Red wire into the terminal marked via a L.

Leave the earth where it is.

------------------------------------------------------------------------------


Any thoughts? Have what I propose correct?

Cheers


Coops



__________________________
Background Info

The ceiling rose has only

1 Red that connects to 1 Brown wire that leads to bulb holder
1 Black that connect to 1 Blue wire that leads to bulb holder
1 Earth.

 

[Steve]

An excellent post, for a simple answer. Yes your solution is correct.

If only all people with real lighting troubles gave such good information with good grammar.

 

[RF Lighting]

Is the plate of your new dimmer switch metal or plastic?

 

[coops1975]

Cheers Steve

 

[coops1975]

Hi RF Lighting

The switch is thermoset plastic

No metal, so no earth needed on switch plate

Cheers


Coops

 

[mikeyd]

If there is only one ceiling rose, then I would have thought the 2 reds which are together would be permanent lives and should go in the terminal marked L, the single red would be a switched live and should go in the terminal marked ~

The problem is the old switch would have worked with the permanant and switch lives either way round, but your dimmer needs them in the correct terminals.

I don't think your dimmer will be damaged either way, so just try it as you proposed, and if it doesn't work swap the single and double reds around.

 

[coops1975]

Mikeyd

Hi, I fixed the switch last night, works fine.

If I wired it the way you are saying would the switch still work?

There is only one ceiling rose.

Which is the correct method?


Coops

 

[mikeyd]

I've a feeling I may have been wrong in assuming it needed the permanant live in the L terminal, and that a dimmer switch will work connected the wrong way round. If it's working I wouldn't worry about it though.
I'm no expert so hopefully someone who is will put my mind at rest ie. Does a 1 way dimmer work wired up with permanant and load connections reversed?

 

[Steve]

Dimmers normally work with the connections reversed, yes.

 

[TicklyT]

A single switch will work either way round, it doesn't care which way round the input and output are, as it has no reference to anywhere else, and the AC voltage feeding it changes 50 times a second anyway.

If it is used as a 2 way switch, then the input and output does become significant, as the correct functioning of the dimmer is dependant on an input from another switch.

Much also depends exactly which convention the manufacturers followed when they made the thing. Some are labelled L1, L2, L3. Others Com, L1, L2 and some are labelled L1, ~v~ (= wavy line & arrow), Slave. There are other labelling conventions too. Each should be assessed according to the manufacturer's instructions and the position of the switch or dimmer in the circuit.
Until they have examined a particular installation, no one can say for certain that terminal L1 will always be a permanent live, or, in the case of 2 way switching, that there will even be a permanent live present at the switch.