All my Varilight soft touch dimmers brightens and dims

[catnipsta]

Hi

I had all my old dimmer switches replaced with Varilight soft touch dimmers. of different power handling models, and were working fine until quite recently.

Now all the sets of LV downlights that are controlled by the new Varilight dimmers continuously dims and brightens...the only way to control them is to switch off the light circuit at the consumer unit. The information sheet mentions that the dimmers safety mechanism comes into affect when the dimmer becomes overloaded by dimming the lights to the minimum level, but does not explain why the lights then brightens again..and so on.

The property in question is in a place with high humidity, could this be the cause?

If one dimmer switchis is overloaded, will this affect the other dimmer switches? Otherwise, why would all the other sets of downlights in the entire flat behave this way?

 

[breezer]

are you saying you have several sets of lights in the house and they are (or at least were) independant, but now they are all cycling up and down?

i should say if this is the case one of two things has happened

you have something new in the house that the switches are picking up,

one switch is faulty and the others are picking this up


if something newto the hose take it away, switch off on lights and see what happens

if not remove each switch one by one

 

[TexMex]

could it be that one of the ring main lives has accidently been connected to the switched return from the dimmer?

 

[breezer]

could it be that one of the ring main lives has accidently been connected to the switched return from the dimmer?

doubtful since

working fine until quite recently.

 

[catnipsta]

I have called Varilight helpline...and they cannot understand why the lightst would brighten and dim in a cycle.

They suspect it could be the atmospheric pressure (the flat is in a region which has hot humid summers)...this could explain why it was working normally previously.

since I am back in the UK, I have asked a friend to test the dimmers before and after cooling the flat with the air-con system.

Varilight are also interested in whether this may be the case....I am suprised that they have not tested these soft-touch dimmers under different atmospheric conditions.

 

[TexMex]

True, but unless ALL of the dimmers have gone awry at the same time, it's hard to understand how a single fault will have affected all of them.

It could be a combination of some imaginative wiring scheme and a failed dimmer that is now affecting others, somehow? God knows? beats me

 

[breezer]

i think you are barking up the wrong tree, try as i said and dissconnect them one at a time, it quite easy for them all to be affected, via mains bourne interfearance, they are all on the same lighting cct, so if one does go wrong it can quite easily affect the others.

as for the comment I am suprised that they have not tested these soft-touch dimmers under different atmospheric conditions

why should they,its not an atmospheric switch, don't suppose bbq makers test them under water do you, they already know what the result will be, so whay test a non atmospheric switch in different atmospheric conditions

 

[catnipsta]

breezer

A Varilight helpline techy did say that their soft-touch dimmers have shown problems when used in kitchens where steam from either kettles or just cooking has affected its behaviour. Apparently the extra humidity affects the dimmer's contacts....so perhaps my point about testing for atmospheric differences seems fair

 

[breezer]

only if you point the kettle at the switch, but like i said bbq makers dont test under water, similarly with touch switches (we also wont mention condensation)

but when are you going to do as i suggested in the first place

 

[catnipsta]

I will probably try to fix it in 2 months time when I return back ...as the property is in another continent.

I am not entirely sure that the wiring is at fault, since the lights did work normal for one day after it had shown problems...I may add that this particular day it was sunny and less humid than other days.

Guess the only way to resolve this is to approach it pragmatically.

 

[TexMex]

as the property is in another continent.

It could be that the man on the treadmill that drives the dynamo is slacking.

sorry. couldn't resist that one.

 

[kendor]

If it was an individual dimmer playing up i'd say it was the "Ramp Capacitor" breaking down this effect is caused by this component failing and giving false triggering of the unijunction transistor which gates the triacs. but all your dimmers doing the same is strange to say the least!

 

[TexMex]

Some dimmers show this behaviour when underloaded. If the property's mains supply voltage was recently dropped, would this not lead to the same result. Not all countries have such a reliable mains source as the UK.

 

[Mr. dimmer]

Just found this site and I have some connection with Varilight so I may be able to help.

This problem that you report has been noted before in a very few cases. A common cause of lights dimming themselves when using Touch / Remote dimmers is that an unsleeved earth touches the heat sink on the back of the dimmer, thus making the dimmer think it is being permanently "touched".

However, in your case this does not appear to be the problem and the other posts could be correct in identifying humidity as the problem. Unfortunately Varilight do not have a definitive answer in this case as the sensitivity of these dimmerswitches is extrremely critical. Cases like this have also been reported when these dimmers have been installed (extremely dangerously and incorrectly) in bathrooms.

It may be that you will never be able to use these dimmers in these humid conditions.

In reply to Kendor - this is impossible as these are not Triac Dimmers.

 

[breezer]

i have a better idea, lets all go home, and let this post lie.

you may not have noticed this bit I will probably try to fix it in 2 months time when I return back ...as the property is in another continent.


note, the word probably, so this means not yes and not no, so we could be debating this for the next umpteen years, since the origonal poster will probably return, but then again they may not, may sell property and have done with it.