Dimmer switch problems

[Ben761]

Good afternoon,

I have been replacing some light switches in the bedroom as we wanted a dimmer but the lights are acting a bit strange so am hoping to find out whether it's something I have done or if it's the new dimmer.

We have a ceiling light and a wall light. The ceiling lights switches at the main switch by the door and operates perfectly.

The wall light also switches at the main switch but also by a switch either side of the bed.

The dimmer is a 2g2w and it is an LED dimmer.

One of the switches by the bed is a 1g intermediate and the other is a 1g2w.

If we turn the wall light on at the main switch it is ok (turns on/off and dims). If we turn the light on from the bed switches, the light comes on fully (not at the dimmed setting that we set at the dimmer). Sometimes, when we turn the lights off from the bed, they turn off and then come back on but dimmer!

Photos below. The wiring at the 1g1w switch is:

3c+e from intermediate: com - brown, L1 - black, L2 - grey.

Many thanks for any help with this.

Ben

 

[Ben761]

Wiring at the dimmer is (for the wall light):

The wiring is loop at the switch wiring.

Supply in and out go to alternate coms on the dimmer with a link wire in between.

Brown from wall light goes to L2 along with grey from the 3c+e to the intermediate.

Brown from 3c+e goes to com (not as it shows in the photo where it went to L1 - an earlier mistake).

Black from 3c+e goes to L1.

All the neutrals are joined in a connector block and all the earths go to the earth connection in the back box.

 

[Ben761]

And I forgot to say previously that if you turn the lights on from the bed, you can't then dim them or turn them off at the main switch.

We are using dimmable LED's. They are 3.6W and there are 2 of them in the wall light.

 

[flameport]

Supply in and out go to alternate coms on the dimmer with a link wire in between.

That is the error.

For the wall lights:
Supply into L1, out to wall lights L2.
The 3c goes to black L1, brown ~, grey L2.

 

[Ben761]

Flameport, thank you.

I have tried that but still have the same issues.

Just to confirm that the supply cable to L1 that you refer to is one of the 2 supply cables I have (supply from previous room and supply to next room)?

Basically I should have a permanent live in L1? And the brown to the wall light goes into L2? The blue to the wall light is with all of the neutrals in the connection block.

 

[Ben761]

And just to give more details, we can turn the light on and off from the dimmer and dim it without a problem.

If the dimmer is off, we can turn the light on and off from the switches by the bed.

But, if the dimmer is on, the wall switches by the bed don't turn the light off. Press the (either) switch once and nothing happens. Press again and the light goes off but then comes back on a second later. And when this is happening, the dimmer switch won't dim or even turn the light off.

 

[ericmark]

An electronic switch be it on/off or dimmer can have many ways to wire it, many use the master/slave configuration, and need an electronic slave, not a standard two way or intermediate switch.

They tend to come with instructions, and only way is to follow the instructions which come with the switch.

Personally the 70's dimming switches have gone into the bin, today it is hey Google set living room lights to 60% and the smart bulbs dim, well with a little luck, not unknown to get reply I don't know how to do that yet.

 

[Ben761]

Thanks Ericmark.

Do you think the issue is more with the dimmer compatibility then?

I have wired it as the manufacturer's instructions.

Seeing as the dimmer turns on and off and dims suggests that the wiring is correct?

The 3 way switching appears to be wired correctly too as you can operate the lights from the bed but only when the dimmer is in the off position.

The whole problem is when the dimmer is on.

 

[flameport]

The dimmer is unrelated.
The problem is due to incorrect wiring.

 

[Adam_151]

Have you removed the unswitched live from the common on the wall lights dimmer as well as added it to L1? - Only the brown from intermediate should be in the common of that gang

Because it is dounding very much like the two far switches are in parallel with the dimmer, rather than than in 2 way arrangement

 

[Ben761]

I have 5 cables coming into the back box.

t+e feed from bathroom
t+e feed to lounge
t+e to ceiling light
t+e to wall light
3c+e to intermediate switch

All blues are connected together in connection block.

The browns from the 2 feed cables go to a common each (one to each gang) and there's a small brown link between the commons. I am not sure which feed (bathroom or lounge goes to which common).

The brown to the ceiling light goes to L1 on the gang for the ceiling light.

The brown to the wall light goes to L1 on the gang for the wall light.

The brown from the 3c+e goes to the common on the gang for the wall light.

The black from the 3c+e goes to L1 on the gang for the wall light.

The grey from the 3c+e goes to L2 on the gang for the wall light.

 

[Adam_151]

All blues are connected together in connection block.

Thats right

The browns from the 2 feed cables go to a common each (one to each gang) and there's a small brown link between the commons. I am not sure which feed (bathroom or lounge goes to which common).

It doesn't matter which is which, but as JW said itr should not be the common on the wall light switch that it goes to, but L1. So one in L1 for wall lights, the other in common for ceiling light, link between them

The brown to the ceiling light goes to L1 on the gang for the ceiling light.

Thats fine

The brown to the wall light goes to L1 on the gang for the wall light.

Move that to L2 as we now have the feed in L1

The brown from the 3c+e goes to the common on the gang for the wall light.

Thats right, it should be the only thing in that common terminal

The black from the 3c+e goes to L1 on the gang for the wall light

Thats right, it should have the feed in that terminal as well (one feed and jumper if you think of it that way) so three conductors

The grey from the 3c+e goes to L2 on the gang for the wall light.

Yes, alongside the brown out to the fittings[/QUOTE]

 

[Ben761]

Thank you Adam. And to Flameport too for their earlier help. It is appreciated.

I won't be playing around with this any more this evening but will let you know how it goes.

The small link cable would go from com on the ceiling light gang to L1 on the wall light gang or to com on the wall light gang?

 

[Ben761]

Now I have thought about this more, I think I know the answer to my previous question.

The supply into L1 should be joined by the link cable from the com on the other gang.

When I previously moved the feed to L1 (flameports advice), I didn't move the link cable with it.

I will do this and see how it goes.

 

[ericmark]

On another post I found this which seems to look like your dimmer, and it also had this I have added the arrow and labelled important wire, what ever colour that wire is not it and make sure centre wire on dimming switch is the Com or L on the other switch, if L1 and L2 are swapped it does not matter that much, as long as L or Com however it is labelled on the switches are correct. I am assuming the instructions are for that switch as posted together on this thread.

I also note LED must be 5 watt or more, I note on bulb compatibility charts it states bulbs should be 5 watt or more, not total of bulbs 5 watt or more, each bulb needs a by-pass resistor and a smoothing capacitor inside the bulbs, often with small bulbs their not big enough to be used with dimming switches which don't need neutrals.

I have stopped using G9 bulbs as a result, as either too small for resistor and capacitor to be included in the bulb, or too big for covers to fit over the bulb. And most other bulbs can be got as smart bulb variant so don't need a dimming switch.

Cheap dimming switches often don't work with LEDs and expensive ones means it's cheaper to get smart bulbs to start with, so the day of the dimming switch is over.