Dimmer switches not turning off- sometimes

[dhnp88]

Hi there, I have a switch plate on my wall with 4 dimmer switches and 2 standard switches. On random occasions one of the dimmer switches will refuse to turn off. I'm happy to get an electrician to repair, but I want to understand the problem.
It doesn't happen all the time, and not always the same dimmer switch. Generally I can turn the problem dimmer switch off the following day after multiple attempts. Each dimmer controls a maximum of 4 down-lights. I don't understand why this problem occurs intermittently not always the same dimmer mechanism. Any ideas why this might occur? Thanks in advance....(Note the switches and dimmer switches were installed by a licensed electrician and it's the intermittent nature of the problem that is so confusing)

 

[mainline]

Hi there, I have a switch plate on my wall with 4 dimmer switches and 2 standard switches. On random occasions one of the dimmer switches will refuse to turn off. I'm happy to get an electrician to repair, but I want to understand the problem.
It doesn't happen all the time, and not always the same dimmer switch. Generally I can turn the problem dimmer switch off the following day after multiple attempts. Each dimmer controls a maximum of 4 down-lights. I don't understand why this problem occurs intermittently not always the same dimmer mechanism. Any ideas why this might occur? Thanks in advance....(Note the switches and dimmer switches were installed by a licensed electrician and it's the intermittent nature of the problem that is so confusing)

Are the led lights at full brightness when the fault is there, if so, then some measurements would be the next step.

 

[dhnp88]

Are the led lights at full brightness when the fault is there, if so, then some measurements would be the next step.

Yes I think the dimmer lights are at full brightness on the occasions I can't turn them off. Next time it happens I will check this specifically. Appreciate any help !!

 

[littlespark]

Are the dimmers turn to to turn on and off, or the push to turn on, turn to dim?

Is it all one in one switch plate, or has it been made up by switch modules on a grid? (Photo of switch)
It might be that the plate is twisted as it’s been screwed back, and the mechanics of the individual switches are skewed, causing issues with how it works.

Also, how old are the switches? As they do wear out over time.

 

[dhnp88]

Are the dimmers turn to to turn on and off, or the push to turn on, turn to dim?

Is it all one in one switch plate, or has it been made up by switch modules on a grid? (Photo of switch)
It might be that the plate is twisted as it’s been screwed back, and the mechanics of the individual switches are skewed, causing issues with how it works.

Also, how old are the switches? As they do wear out over time.

Thanks for helping me! The dimmers are the type that push to turn on and off, and turn to dim. They are approximately 4 years old. I'll definitely try unscrewing the plate and checking if there is any obstruction that might be pressing on the plate and dimmer mechanisms. (photo of plate front attached)

 

[littlespark]

Just slacken the screws a little without taking whole thing off.

If the wall isn’t quite smooth, the plate will disform as it’s tightened back.

Might be completely off with the suggestion, but maybe

 

[Avo Mk8]

Those Clipsal/Schneider dimmer modules are somewhat different from what I'm used to (more compact and with flying leads, as compared to equivalents here in the UK).
The data sheet, assuming I have the right one, shows they are fairly sophisticated with overcurrent and short circuit protection, thermal protection, a 'kick start' feature etc, etc. It also describes adjusting the minimum light level through a physical stop 'adapter" which is part of the knob. So the knob adapter has to be put on with the correct orientation when you put it back (assuming yours has this feature).
Also I note the power rating of each dimmer gets significantly de-rated (halved) when you have three in a row, as you do, but I imagine your bulbs won't be exceeding this. It also says maximum three dimmers per plate. Does the front plate ever get warm?

It might be worth tracking down the correct data sheet for your dimmers if this is not the right one:

https://download.schneider-electric.com/files?p_Doc_Ref=JYT4082309

The problem might just possibly be a mechanical issue whereby the knob/adapter combo, or the position of the front plate, interferes with being able to press a knob in far enough to trigger the on/off switch mechanism.

 

[dhnp88]

Those Clipsal/Schneider dimmer modules are somewhat different from what I'm used to (more compact and with flying leads, as compared to equivalents here in the UK).
The data sheet, assuming I have the right one, shows they are fairly sophisticated with overcurrent and short circuit protection, thermal protection, a 'kick start' feature etc, etc. It also describes adjusting the minimum light level through a physical stop 'adapter" which is part of the knob. So the knob adapter has to be put on with the correct orientation when you put it back (assuming yours has this feature).
Also I note the power rating of each dimmer gets significantly de-rated (halved) when you have three in a row, as you do, but I imagine your bulbs won't be exceeding this. It also says maximum three dimmers per plate. Does the front plate ever get warm?

It might be worth tracking down the correct data sheet for your dimmers if this is not the right one:

https://download.schneider-electric.com/files?p_Doc_Ref=JYT4082309

The problem might just possibly be a mechanical issue whereby the knob/adapter combo, or the position of the front plate, interferes with being able to press a knob in far enough to trigger the on/off switch mechanism.

View attachment 121828

Thanks everyone for the advice, I'll follow up all suggestions ASAP. I'll get the data sheet, and have a really close look if there is any mechanical interference (so obvious but I had not thought of it). I'll slacken off the screws too. Whilst I have 4 dimmers instead of the recommended 3 maximum, I suspect they are at a fraction of their load capacity and I really don't think overheating is the problem,
I'll report back on the outcome....
THANKS AGAIN - THIS HELP IS VERY MUCH APPRECIATED

 

[dhnp88]

thank you, this solution has worked and continues to work so far