flickering downlights only with dimmer

[AJ16]

[h=2][/h]

I fitted 5 Click 50W 240V downlights and a Click 400W dimmer. The dimmer failed after short time. I just tried a 400W dimmer from Denmans but it flickers badly more so when on turned round to the fully on position. There is a normal 1 gang two way switch at one side of the room and the dimmer is the other side. When there is a normal switch each side everything is fine, it's just when a dimmer is fitted that the flickering starts. Is there an obvious reason for this to be happening?

Thanks AJ​

​

 

[truckster]

Many dimmers need to be de-rated 50% for halogens, so 5*50=250 you need a 500w dimmer.

 

[AJ16]

ok I'll give it a try thanks

 

[JUD]

Many dimmers need to be de-rated 50% for halogens, so 5*50=250 you need a 500w dimmer.

Isn't that only because of inrush currents when a halogen lamp fails. I can't see the wattage rating of the dimmer causing the flickering, it's more likely that the dimmer is faulty.

Also, a lot of dimmers today no longer need de-rating.

 

[BlueToBits]

I think the de-rating issue is because TH lamps due to their shorter and thicker filaments have a lower cold resistance, so draw a higher current when switching on. Sholdn't cause flickering though. More likely to be contamination or degredation on the carbon track in the potentiometer, Could be a faulty diac mis-triggering?

 

[AJ16]

thanks for the replies, I phoned Denmans today and they said they don't sell a 500W dimmer, the next size up is around 1KW and expensive. I'm thinking there's something else causing the flickering but can't think what if all the lights are steady on with normal 2way switches.

AJ

 

[Simlec]

Mains lamps need no de-rating only 12v with transformers.
To see if you are overloading your dimmer simply remove lamps and try say 2lamps to start with, if they still flicker then it’s your dimmer or wiring.

 

[Richard]

Have you tried taking some of the lamps out? I doubt it will solve your problem, but it's worth a try.

 

[miner69er]

i have found one of the biggest causes for flickering is dirt on the contacts inside the switch. have you checked the standard switch (not the dimmer) or replaced it to see if it is the standard rocker switch that's the problem? that's where my money would be.
happy hunting.

 

[Spudnik]

Def duf dimmer.

 

[AJ16]

i have found one of the biggest causes for flickering is dirt on the contacts inside the switch. have you checked the standard switch (not the dimmer) or replaced it to see if it is the standard rocker switch that's the problem? that's where my money would be.
happy hunting.

I put a new standard switch the other end but the flickering is still there and the dimmer is still noisy, I might try a diff dimmer but Denmans reckon they don't often get them returned.

 

[AJ16]

I just tried replacing the standard switch with a new one but the problem is still there so there must be a problem with the second dimmer purchased, or something up with the circuit although everything is fine with just std rocker switches.

Has anyone else got on ok with 5 or more 50w 240V lamps off one 400W dimmer? I'm thinking I need to do a test rig with 5 lamps attached to one dimmer and see if the results are the same.

 

[AJ16]

Many dimmers need to be de-rated 50% for halogens, so 5*50=250 you need a 500w dimmer.

Have you bought 500W dimmers before truckster?

 

[AJ16]

Mains lamps need no de-rating only 12v with transformers.
To see if you are overloading your dimmer simply remove lamps and try say 2lamps to start with, if they still flicker then it’s your dimmer or wiring.

I'm trying but the lamps won't come out! It's weird but they all seem jammed in, I've tried taking the downlights out but it seems to be tricky to avoid damage to the plaster as they are a tight fit

 

[malcolmsanford]

Lutron Lyneo Single 500 Watt Preset Light Dimmer - LLSI-502-H-F - lutron lighting | eu online shophere are loads of 500watt dimmers available.

If you have a cheap dimmer switch, you can have a strange buzzing noise. This comes from vibrations in the bulb filament caused by regulating the wave form coming from the triac. Better dimmer switches have extra components to quel the buzzing effect

 

[AJ16]

Lutron Lyneo Single 500 Watt Preset Light Dimmer - LLSI-502-H-F - lutron lighting | eu online shophere are loads of 500watt dimmers available.

If you have a cheap dimmer switch, you can have a strange buzzing noise. This comes from vibrations in the bulb filament caused by regulating the wave form coming from the triac. Better dimmer switches have extra components to quel the buzzing effect

It all seems very expensive on that website!