Dimmer switch

[Twoon]

Help,

I have just bought a dimmer switch to replace my exisiting switch. On the instructions it says to make a note of the wiring and put the same wires in the same holes on the new switch which i have done but it doesnt work.

There are two sets of wires in the box. On the original switch one red one from one set went into L1 and from the other set the red one went into L2. The other wires in the sets are just in a proctector box thing (two black and two green wires).

Does anyone know how how to wire it correctly?

Teresa

 

[ban-all-sheds]

I have just bought a dimmer switch to replace my exisiting switch. On the instructions it says to make a note of the wiring and put the same wires in the same holes on the new switch which i have done but it doesnt work.

Doesn't turn on?

Doesn't turn off?

Turns on/off but doesn't dim?

There are two sets of wires in the box. On the original switch one red one from one set went into L1 and from the other set the red one went into L2.

What terminals on the dimmer did you put these into? Are there 3? If so is the one you didn't use labelled COM, or C, or have a wavy line next to it?

The other wires in the sets are just in a proctector box thing (two black and two green wires).

Protector box??

Are any of them joined together in any way?

 

[Twoon]

Hi,

Tlight doesnt turn on (sorry i should have put that shouldnt I)

On the original switch one of the red ones went into L1 and the other red one went into L2 so this is how i have put them into the dimmer.

The two back wires are just blanked off (i think thats a better term than protector!) as were the two green wires.

So the only wires i have connected are the two red ones one in L1 and one in L2.

None of them are joined apart from the two green ones which are in one sleeve together but not twisted together or anything.

 

[dave2506]

On your old switch, what were all the terminals labelled as? And similarly what are the labels on your new switch?

It sounds like you have a 2-way switch and their terminals can either be labelled as C, L1, L2 or L1, L2, L3 respectively. Therefore if they are different then L1 and L2 are not necessarily the same on both switches.

Hope this makes sense!

 

[ban-all-sheds]

On the original switch one of the red ones went into L1 and the other red one went into L2

Does the old switch have a 3rd terminal labelled L3?

so this is how i have put them into the dimmer.

Does the dimmer have a 3rd terminal labelled COM, or C, or with a wavy line next to it?

The two back wires are just blanked off (i think thats a better term than protector!)

Do you mean they're in a piece of choc-block?

None of them are joined apart from the two green ones which are in one sleeve together but not twisted together or anything.

Are those properly connected together with choc-block?

Does the switch have a metal faceplate, or is the back box metal?

 

[Twoon]

Hi,


Yup there is a L3 hole on the old switch but there was no wire in it.

Yup the new dimmer does have the C hole.

The black and green wires are in a choc block but they arent one in one side and the other in the other. Both sets of wires are just in one hole (2 green in one hole and 2 black in another), as if just to keep them tucked away.

The new swtich is a metal one. The old one was plastic. The back box is a plastic one.

 

[dave2506]

Right OK - now we're getting somewhere

The labels on the terminals on your 2 switches can be transferred as follows:
L1 -> C
L2 -> L1
L3 -> L2

Therefore (assuming your switch worked before) put the red wire that was in L1 into C on the new switch and then the red wire that was in L2 into L1 on the new switch. This should get your new switch working.

Regarding your other cables that are in the connector block - they are connected together (it does not matter if they are in the same side or opposite side of the connector block). Don't worry about the black wires but as your new switch is metal you will need to make sure there is an earth wire attached to it.

To do this take a short lenght of 1.5mm wire from the connector block with the green wires in and connect it up to the earth point on the new switch (remember to put some green/yellow sleeving on it).

It would also be a good idea whilst your there to wrap the connector blocks separately in electrical insulation tape.

 

[Twoon]

You're a star thank you very very much.

 

[dave2506]

No problem - glad to have helped.

Having thought about it a bit more, you could just do away with the connector block altogether on the green wires and simply connect the green wires directly to the earth terminal on the new switch.

Both would be OK - this method is just a bit tidier!

 

[RF Lighting]

It would also be a good idea whilst your there to wrap the connector blocks separately in electrical insulation tape.

Why on earth would you want to do that?

 

[Twoon]

Hi,

Have tried the wiring you suggested and it still doesnt turn on.

Could I have bought the wrong switch? it says dimmer switch single 400w 2 way low voltage chrome?

 

[Steve]

So you have a red wire in L1 and another red wire in C?

 

[Twoon]

Yup definately

 

[Steve]

Try the 2 wires in a normal switch, maybe the old one. If the light works, you've broken the dimmer by connecting it wrong to start with. Sorry.

 

[Twoon]

Oh! thank you for your help.