Dimmer problems

[daggermark]

In my lounge I've got 2-gang 2-way dimmer switches, 1 gang is for wall lights and the other is for ceiling. They are Varilight V-Plus, 1 master and 1 slave unit. I previously had issues with 1 gang (https://www.diynot.com/diy/threads/dimmer-switch-issue.528383/ for reference), and got a replacement.

The wall lights have 4x40w and the ceiling 6x40w, so both well within the power range of this switch.

Unfortunately, the replacement didn't last long either (~ 8 months) as a blown Halogen damaged the dimmer. Varilight have since recommended that I replace the bulbs with a more reputable manufacturer such as Osram, which I have done.

Well, the latest switches were fitted last week, all well and good... until yesterday, when they've started to play up again. Both gangs are showing the same behaviour - if I turn the lights on, they come on dimly for 2 seconds and then turn themselves off. If I cycle the MCB, everything is back to normal and the lights work again for a day or so, when I have to repeat the process. This happened before with the first unit before it completely failed, so I'm waiting for the inevitable now.

I temporarily ran a regular light-switch for a few days in the interim period between broken switch and replacement, and everything was fine.

I am tearing my hair out with this thing and cannot fathom what could be causing the problem. Before I go to regular light-switches once and for all, has anybody got any idea what could be causing these continual failures? I've put a multimeter on various points in the circuit and it all looks good and consistent.

 

[ericmark]

It is interesting what you are saying, as I have had same problem with electronic switches doing odd things and I have returned to using simple on/off in the main room instead of using wifi switches because as you have found I would need to turn power off/on to lighting circuit every so often to get it all working again, and I am using LED bulbs 8 x 6 watt E14 candle.

In one bedroom fitted a load capacitor and tried different makes of bulbs to stop flicker, in the end only way is have one bulb quartz which stopped flicker in all bulbs.

However I fail to see how you can use a dimmer with tungsten bulbs today, the old tungsten bulb worked great, and there was a fuse in every bulb so if when the filament ruptured you got ionisation of the gas in the bulb (bright flash as it blows) the fuse would stop it overloading the circuit and causing all lights to fail, it also gave some protection to electronic switches, however as bulb manufacture moved to China this fuse seemed to vanish from bulb manufacturer, and then we got quartz, now the whole idea of quartz is the quartz is so hot the tungsten will not adhere to the quartz but returns to the tungsten, so the bulb must be run very hot, or the quartz goes black as the tungsten adheres to it and they have a short life, plus because quartz is so hot it needs a glass to stop the white hot bits being released when it blows plus stop some harmful rays, so putting it simple you should not dim quartz bulbs. Yes I know you can, but it shortens the bulb life, and defeats the whole idea of using quartz.

So big question which should a manufacturer of a quartz bulb worry about their use with dimmer switches, when your not suppose to use them with dimmers to start with?

However I realise there is a problem getting the old tungsten bulbs, EU rules mean they can only be sold as rough service bulbs, however if you want to dim them anyway, having a redder colour from the bulb is hardly a problem, the whole idea of dimming is ambiance, and the rough service bulbs do give the ambiance, and the standard LED is useless as when dimmed the colour stays the same.

Also to use electronic switches with LED bulbs under 5 watt each or 10 watt in total, as found to my cost you need a neutral at the switch, I would love to know why bulbs under 5 watt tend to flicker, but all I know is they do. There has been an attempt to return to the ambiance with LED bulbs which within the bulb you can set the hue, and dim them, up to now not tried them.

In the early years of the so called energy saving move, I changed the chandeliers to take more bulbs and fitted in living and dinning room 16 Philips 8W golf ball CFL bulbs, they had a massive claim as to run hours, and switched on reddish then slowly went whiter which was a nice effect and did not wake my wife when switched on, however within the year over half had failed, so that was the end for me buying expensive bulbs, cheap bulbs seem to last longer, OK with LED only 2 have failed a G9 and a fluorescent tube replacement, but latter was nearly £20 and so an expensive failure compared with fluorescent tube it replaced.

I realise LED bulbs don't really save energy, as most of the time they are used in doors we want the heat anyway, however in the main they last longer, not necessary cost efficient as cost more to start with, but gone are the days of the cupboard full of spare bulbs and swapping a bulb a week some where in the house, I now only buy a bulb when one fails, however this means using a bulb you can buy on the high street, from a food shop as many of the electrical shops are closed, which rather limits the range of bulbs. I still have a stock of pearl tungsten bulbs BA22d, only problem is very few of my light fittings take BA22d bulbs. Only in the rooms not used much, so that stock will likely last until I die.

So it seems the way forward is the wireless linked LED bulb, £8.10 each

personally with 8 bulbs in the living room £64.80 is more than I want to pay for lights. I have decided I will need to use my legs to turn on the main lights.

 

[davelx]

Why are you using halogen lamps in this day and age? I'm not saying LED with dimmers won't have problems but you won't be consuming 400w for lighting.

Well, here's one possible reason:

I still have 4 x 40W halogen lamps in my up-lighters. If you can point me to a dimmable G9 LED that is the same size as a standard 40W G9 halogen and with the same light output I will gladly swap them out. The max G9 LEDs I can find are only 3W and they are much longer than a standard halogen G9 so wouldn't fit even if they were bright enough (I bought a couple to try).