lights gone again

trailingspouse

We had the house completely re-wired 18 months ago, when we moved in.

We have a 5-bulb chandelier in the living room, and also a 3-spot ceiling light in the same room. They both run off dimmer switches (2 separate dimmer switches on the same back plate, if that makes sense).

I switched the main chandelier on this morning, and it went pop. Fused the lighting circuit. Once I'd reset the fuse, all the other lights on the circuit were functioning normally, apart from the chandelier. This is the second time it's happened. Last time, we needed something in the dimmer switch replacing.

I'll be calling the electrician today. It's the same guy who did the re-wire and fixed it last time, and I have absolutely no reason to think he's done anything wrong - but nevertheless I would appreciate thoughts from anyone out there who might be able to give me an idea of why this is happening and what we can do about it. It's getting expensive!!

MoneyMate

Are the dimmers compatible with the Bulbs used ?

brightontraveller

Most likely wrong choice of dimmer there are many types Resistive Dimmers (Leading Edge) (Trailing Edge)etc also check loading of Lamps (bulbs) is whithin limits of dimmer
etc
This should explain it
http://www.universal-lighting.co.uk/buying-guides/choosing_the_correct_dimmer_switch

Could also be the two dimmers together are getting hot in the back box shortening lifespan

sparky260500

Ive had this before Its nothing to do with the electrician when you replace the dimmer you will see one of the lamps have blown. Bet they are candle shape lamps change the lamp for the type that don't have the filament (looks like a small piece of wire ) inside. Its that filament that breaks and shorts out hence blows the dimmer.

sparky260500

brightontraveller wrote: »

Most likely wrong choice of dimmer there are many types Resistive Dimmers (Leading Edge) (Trailing Edge)etc also check loading of Lamps (bulbs) is whithin limits of dimmer
etc
This should explain it
http://www.universal-lighting.co.uk/buying-guides/choosing_the_correct_dimmer_switch

Could also be the two dimmers together are getting hot in the back box shortening lifespan

No 2 gang dimmers are meant to work together

brightontraveller

sparky260500 wrote: »

[/COLOR]
No 2 gang dimmers are meant to work together

Incorrect some are? Many will work together but depends on make manufacture, dissipated energy, loading etc people are often surprised at the heat lutron for one 140º F (60º C)
Dimmers do get warm some more than others and efficiency is typically around 99%. (Varies with different manufactures) The other 1% (some as high as 5%) dissipated in the dimmer as heat. So, at 1% 600 W loads on a 600 W dimmer would produce around 6 watts of heat approximately the heat generated from a small nightlight. (Higher dependant on efficiency). Grouping certain makes of dimmers together heat they produce affects the dimmers lifespan….

If we take your diagnostic ( not one I agree with but )“Its that filament that breaks and shorts out hence blows the dimmer” If you look at that in more depth this would mean every time lamp blows * between 500 hr and 10000 hr dimmer could need replacing???

Correct dimmer/ lamp selection made initially greatly increases lifespan as this would be third dimmer I would go with wrong selection of dimmer compatibility with lamps, loading etc pointing too uninformed electrician or poor quality replacement used every time ?

mavisangelica

In our old house (built 1994), if a bulb 'went' then it would often trip the lighting circuit. Then we were just using ordinary light bulbs. Just presumed that the circuits were just sensitive.

brightontraveller

mavisangelica wrote: »

In our old house (built 1994), if a bulb 'went' then it would often trip the lighting circuit. Then we were just using ordinary light bulbs. Just presumed that the circuits were just sensitive.

Not quite the same thing and often cured with correct fuse selection not rating but type

izzy65

Is it possible that there is too much of a load for the dimmer if the chandelier has multiple bulbs:)

trailingspouse

Thanks for all your replies.

Re- overheating - this happened first thing this morning, so no lights had been on for about 7 hours. Although I guess that overheating over a period of time could result in damage that might happen when they weren't actually overheated?

The house is 100+ years old - but the re-wiring only happened in 2013.

I've been totally happy with the lecky up to now - very professional, VAT registered, logo'd van and polo shirts, has been trading in this area for 20 years. I don't think the problem would be lack of knowledge on his part.

They are indeed candle-type bulbs, because they work best with the style of the light fitting and the room in general. Could the total wattage be too much for the circuit?

There was one bulb already out, which had 'popped' a couple of days ago without causing any fuss at all!! Maybe a second bulb blowing was too much for the system to cope with?

Apologies if some of my questions are a bit dim (see what I did there??).

brightontraveller

Logo, polo shirts vat registered been trading years wish they did make a firm good


Lightings come along way in the last few years multitude of types but alias many don’t keep abreast of changes… often the effects of over heating are more of a issue at start up when cold so to speak not so much when running they don’t often get hot enough to set on fire just enough to make them brittle or component break down when starting cold if there are 5 bulbs at 50w each then dimmer needs to accommodate this most domestic dimmers are rated 200 / 400w so 400w should work fine 200 w will still work but will breakdown quicker due to loading heat etc

Most 400w dimmers are 1 Gang 2 Way think only one or two make 2 gang because of the heat... You can get separate grid dimmers but again most manufactures dont recommend putting these together because of heat or they have seperate dimmer packs See if the dimmers are 200w 400w etc and the loading of the lamps eg add them upp 5 x 50w etc