Halogen GU10 bulbs blowing my flat face dimmer - HELP

[Colleencatface]

Can anyone give me some advice in basic female (I know nothing) language? My kitchen has 10 Halogen GU10 downlighters and every time one of the bulbs blow it blows the (very nice looking) flat faced dimmer. I have just spoken to an electrical wholesaler about this and he said that Halogen bulbs are bit rubbish with dimmers and this will keep happening. He suggested replacing the halogen lights with LED 5W. We also have a double gang 2 way retractive switch in another room which opperates the same lights and this one seems ok because it hasn't blown yet. Does anyone know if replacing the bulbs with 5W LED will stop this problem? I like having a dimmer and wondered if there is such a thing as a double gang 2 way retractive dimmer switch? Or is it best to not have a dimmer etc? Can anyone HELP? Many thanks

 

[mfarrow]

With 10x GU10 lamps, this will be a minimum of 200W or 200VA with 20W bulbs, or 500VA with 50W bulbs.

What is the rating of your dimmer switch? It will be written on the back of the module and should be greater than the combined rating of the bulbs in order to take the load.

It sounds likely that the dimmer switch isn't rated for the lighting, and any lamp blowing is just pushing it over the edge. Lamps with a lower rating (i.e. LED) should stop this happening.

 

[Colleencatface]

Many thanks. I'll have a look at the dimmer when it comes off the wall.

 

[333rocky333]

wondered if there is such a thing as a double gang 2 way retractive dimmer switch?

Whats a retractive dimmer

Maybe you could buy two singles like the one you have, remove the modules and fit on your double plate.
As said the load rating needs to be compatible too

Fitting leds they will also need to be compatible with the dimmer

 

[sparkybird]

Where are you buying your bulbs from? If it's Tesco Value then stop!

Buying a branded bulb eg Philips, Osram, GE will help as each time a bulb blows it creates a tiny short circuit which is why your dimmer gets killed. Better quality bulbs avoid this problem (and will probably go less often)

 

[stillp]

Bear in mind that halogen bulbs don't like being dimmed so are far more likely to fail when fed from a dimmer.

 

[ericmark]

The reason the dimmer fails is most likely ionisation of the gas inside the halogen bulb. When any tungsten bulb blows it can result in ionisation and inside the bulb in theory there should be a fuse built into it which will rupture so stopping a single bulb failure from opening the main protective device (Fuse or MCB).

However there are many cheap bulbs where this is missing and as a result it will take out the main fuse/MCB or if there is something weaker like a dimming switch it will take out that.

With any bulb not designed to be dimmed one can not really complain if when used outside it's design and the quartz halogen lamp works by keeping the envelope (quartz) so hot that the tungsten will not settle on the quartz but back on the tungsten element as a result they should be never run cool. So dimmers should never be used with quartz halogen lamps.

As a result one can hardly complain when you do something for which they are not designed for some thing fails.

The other problem is 10 x 50W lamps use 2 amp and the total for most lighting systems is normally 6 amp so it is common for people to fit protective devices too big for the system which means the dimmer fails rather than the main fuse or trip. Also for a short circuit a fuse can rupture quicker than a trip will open as a result semi-conductors (which are inside the dimmer) are normally protected by a fuse rather than a trip and where a trip is used the instant magnetic part needs to be as low as we can get so type B not a type C. So the trip should be marked B6 not C10 and sorry to say finding a C10 fitted is common when people have fitted these spot lights.

With a LED lamp when dimmed often the colour stays the same only the light output changes and where the dimmer is used to give the reddish warm glow they do not really do the job. Yes using a dimmer with the special dimming LEDs will reduce light but splitting the LED's with 4 on one switch and 6 on another would also give three levels of light without using any dimmer switch.

The spot light is clearly designed to give a spot of light rather than general lighting but by aiming at a white or light surface like walls or ceiling the reflected light can be used as general lighting but when cooking in a kitchen the idea is to get as much heat into the food as you can and as little into the room as you can moving from solid fuel to gas reduces the heat in the kitchen as does moving from gas to electric induction hobs to then replace this heat with inappropriate lighting just seems daft.

I think you really need to think about the way forward and decide if the kitchen is a work area or leisure area if it is a work area then design it to help you work rather than look pretty. OK there has to be a balance. I think to have lights aimed at work surfaces to give extra light to that area is good. However there is really only two states required on or off.

 

[ban-all-sheds]

Buying a branded bulb eg Philips, Osram, GE will help as each time a bulb blows it creates a tiny short circuit which is why your dimmer gets killed. Better quality bulbs avoid this problem (and will probably go less often)

I have never, ever, known a quality branded lamp (GE, Osram, Philips etc) with a Ballotini fuse NOT trip the MCB when it fails, so there's clearly still a surge, even with those.