GU10 - 4 lamp spot light - Something odd...

[Dzzi]

Hi
My first post and i'd like to apologise in advance for the length of this post but i know how important it is to have all the information if you are going to help with a potential diagnosis.

A while back i fitted a 4 spot light gu10 bar type light and dimmer switch in my sons bedroom. While im not in anyway an electrician my Dad was and i am confident when dealing with the basics of replacing light fittings/switches.

Anyway all went fine, its been working for a year then on Sunday all the lights upstairs went out, the breaker (mcb??) had flipped and i pushed it back on with no issue, all lights back on except in my sons bedroom.

I know gu10's can be problematic so i thought, outside chance all 4 bulbs blew for some reason. My other Son has a similar light fitting, i took all the working bulbs out of his light and then tried the bulbs from the faulty light 1 at a time in this fitting 2 out of 4 failed to light.

I then took a known to be working bulb back to the light fitting that had the 4 none illuminated bulbs and tried it in each of the 4 holders one at a time, and nothing.

Other background info. I think my son has been leaving the dimmer on i.e. turning it right down and not switching it off by pressing it, or at least this is what my wife thinks he's doing.

The fitting is from screwfix (sorry if im not supposed to mention that) they no longer do it and im wondering if that is due to it going faulty after a while.

Ok so, I can understand 2 blown gu10's but why when i put a known bulb in each holder in turn does it now not work ?

I've not taken the fitting down as it's dark when i get home and i am concerned something outside my experience has happened here...so want to turn all the power off before i touch it.

Anyhow any advice or futher questions really welcomed as at the moment i can see myself forking out for a new light.

Thanks

Dave

 

[sjm]

Just a thought, and I'm sure someone will be quick with a better idea, but cheap non integral fused GU10's are prone to blowing up dimmer switches when they fail.

 

[Dzzi]

Thanks, i hadn't considered that, would it be visually obvious if that that had happened or would it be best to just put a spare switch back in place of the dimmer and re-test ?

 

[sjm]

Yep try a spare switch in place of the dimmer.

 

[DurhamSparky]

agreed put a normal 10Amp switch in place!

chances are dimmer has fooked and burnt out!!

 

[Dzzi]

ok thanks gents will give that a go first

 

[Sparks-R-Us]

Hi, GU10's are prone to blowing up dimmer switches when they fail. When the spot fails, the inrush of current to the internal circuit of the spot fries every electronic circuit connected to it i.e the dimmer which in turns trips the main circuit. you could check this using a multimeter(set to ohms) across the dimmer circuit and switch on then turn up the dimmer and the resistance/reading should go up. But the hassle is not worth the effort considering the cost of a new one...Leaving the dimmer switched on to low puts a heavy heat on the dimmer internal circuit so when turned up pulls to much current, thus causing the spot to blow and trip the system...Hope this helps

 

[Dzzi]

Hi and thanks for all the replies, so assuming it is the dimmer switch thats failed, ive been looking at replacement ones, again i think i got the original from screwfix and i wasn't aware of the issues with dimmers and gu10's.
Again sorry if this breaches forum protocol but would anyone care to comment on these 1 Gang 2 Way 400w iQ Dimmer Switch - Gun Metal as replacement.
Has to be a metal look switch Son's orders !

 

[flyingsausage]

If your Dad is a spark get him to sort it

 

[Dzzi]

...was... Mr Sausage ...was.. have a think why i've not asked him matey

 

[flyingsausage]

...was... Mr Sausage ...was.. have a think why i've not asked him matey

I have no idea,you may have fell out with him
Another thing to look out for is one of the cables may have popped out of it's connection and broke the circuit,this is very common

 

[DurhamSparky]

I have no idea,you may have fell out with him

he gave you the most obvious hint mate!

His Dad WAS a sparky... you only become WAS for one reason....!!

 

[flyingsausage]

Looks like I put my doot in it

 

[Dzzi]

thanks for the other suggestion, will let you know how it goes

 

[oldtimer]

GU10 as said above are prone to blow the circuit breaker when they expire and the 4 light track jobbies like yours can cause a lot of hassle because these lamps can have 1000,2000 or 5000 lifespan hours no big deal you say but the ammount of times I have been called out with the "On Monday one of the lamps popped the CB then Wednesday another lamp went out and on thursday the same whats wrong with my electrics" Nothing is the reply as these lamps are manufactured to tight tolernces the will go around the same time as each other.

 

[Dzzi]

now that is interesting i have noticed and moaned about a run of bulb failures in the kitchen etc, but hadn't considered that the tolerances would be that tight they would go within days of each other...
So in my case maybe 2 gu10's failed at the same time and fried the dimmer...

If anyone fancies commenting on the dimmer i linked to above i would be grateful.
The fact TLC have a dimmer specifically for GU10 lights seems to support the opions of the erstwhile forum members...

 

[Sparks-R-Us]

Hi Dzzi, have a look at the total specs of the dimmer here(http://www.varilight.co.uk/leaflets/varilight_catalogue.pdf) then make your choice...There is a new dimmer out(J1 series) which is Silent Intelegent(all loads including transformers and GU10's)...Home this helps

 

[Dzzi]

just a quick update, bought a new non dimmer type switch fitted it...all worked fine.
managed to get a replacement dimmer unit for the original one, not much cheaper but meant i could keep the original switch plate etc, which matches the other sockets in the room.

Thanks for the advice, i would have probably taken the light fitting down for a look first, so you all saved me sometime.
Cheers Gents.

 

[telectrix]

if it goes again, dump the dimmer, fit a 10A rocker switch and buy your son a pair of shades.

 

[oldtimer]

I had a tenant who said there something wrong with the electrics the lamps are popping at the same time in the kitchen but the funny thing is that the 2 in the alcove are fine. So do you switch the alcove on at the same time as the kitchen. No she said I hardly switch them on at all and you dont see them popping at the same time she said

Aye every day is a school day