varilight 2x250 switches on automatically

[yattong]

I have bought a varilight 2x250W screwless touch dimmer.
On 1 gang is 4x35W.
On the other is 2x35W.

For some god damn reason, the 2x35W seems to have a mind of its own and switches on by itself. Sometimes full beam, sometimes lowest.

This however doesnt happen, when i do not put the screwless plate on.

I have tried 3-4 different 2x250 switches, from 2 different suppliers and still get the same problem. The last dimmer was fine for over 2 days with the plate on, but has now started to play up like the others before.

I have also tried putting all 6x35W onto a 1x250W touch dimmer and is fine.

I dont get what the problem is.

HELP!!!

 

[RF Lighting]

What is the minimum load for the dimmer switch?

What sort of lighting are you trying to dim?

 

[yattong]

hi,

Im using the MR11 spotlights. (the 35mm ones).
Also using LV transformers which are dimmable.

Ermm... minimum load?

not sure, it doesnt say on the box and ive asked both suppliers if 70W is ok, and theyve said it was.

 

[breezer]

if it only does this with the screw less plateon, i would guess its picking up damp.

I am guessing the switch works by detecting change of capacitance, adding the plate means it is detecting the wall, any change in capacitance i.e damp and it changes state.

only a thought

 

[yattong]

thanks breezer...

The wall it is fitted to is a hollow wall, with just insulation inside.

If it was getting damp, would the 4x35W be going funny (switching on auto) aswell? or would it just affect the 2x35W?

 

[breezer]

i just re read your post, i just notced its only one side of the 2 gang that does it

it must be a combination of the minimum load and capacitance.

humour me.

wear a rubber glove, touch the switch does it work? (with the gloved hand)

if nothing happens the switch is working by capacitance (or simiilar) since the glove is isolating you

 

[yattong]

just tried it witha pair of marigolds.

neither switch works.

 

[breezer]

one would have done.

so you have just proved the switch works by detecting the change in capacitance (since by wearing the gloves it isolates you)

this means that when you put the "cover" back on you are connecting the switch to the wall (by capacitance) hence something in the wall is changing so the switch operates.

i do not g'tee the following will work but its worth a try.

put insulation tape around the switch cover where it touches the wall (only the small edge that touches the wall)

in theory it should isolate the cover from the wall

 

[yattong]

hi guys,

thanks for the help.

The plate is isolated from the wall by the screwing-in plastic plate in which it clips onto. If that makes sense.

Ive rechecked the wiring to the bulbs and made sure everything screwed together properly. One may have been a bit loose. (hence maybe crossing the minimum load?). All tight now.
Plate back on, and no auto lights on yet.

Will post back in morning or in a few days like before, if it does.

 

[yattong]

Man.. this is doing my head in.

With the screwless plate on and 2 bulbs in, the lights come on auto.

If i take 1 (either) of the bulbs out, no problem. So it cant the minimum load that is causing the problem.

Could it be the transformer that is the problem?
Its a 35-105 elec dimmable transformer.