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[Closed] Electricians of STW - Why do my LEDs keep blowing?

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We put a new kitchen in 2.5 years ago with 10 x GU10 spotlights in the ceiling. We fairly swiftly replaced the 50w bulbs with some good quality LEDs from Simply LED on t'interweb. These are fine and should last a long time, or so we were lead to believe. They weren't cheap either.
Anyhow after about 6 months one blew and was replaced for free and since then another 3 have blown, one a couple of weeks ago and one just now. The first 2 were replaced for free, but we've not heard about the last one yet (or today's obviously)

But why are they blowing?

All the wiring from the switch to the lights in new, the house electrics were all checked and/or replaced over the last few years too. The fittings were new at the time, but a pretty basic set from Screwfix. The lights are in two independently switched banks of 5 controlled from a single triple switch that also controls the counter lights. All new with the kitchen
It's a different one that blows each time too.

Any ideas?


 
Posted : 14/04/2013 7:02 pm
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It's the LED's. What make are they?


 
Posted : 14/04/2013 7:07 pm
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No name on them. Simply LEDs own I think. I read about the cheap ones at the time and avoided them though.

The ones under OLD here

http://www.simplyled.co.uk/NxtGen-LED-Bulbs_B2583N.aspx

They are 2 years old now, so I'd expect something newer own the website, but these should have lasted longer than this.


 
Posted : 14/04/2013 7:09 pm
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Ok, These retrofit leds have to pack a lot into a tight space in order for them to fit into halogen light fittings, which means their life is "technically" half the life of a dedicated LED fitting. That means the driver will get affected by heat a lot more and the heatsink isn't as comprehensive as dedicated LED fittings.

It may be worth you checking that there is enough free air around the fittings in the ceiling, I.E, no insulation around them.

What also comes into it is who the manufacturer of the leds bulbs are. I've had a look on simplyleds website, and their own brand pretty much look the same as the bulbs offered by a few other online websites. Kosnic have been producing LEDs or a few years, but have suffered from reliability problems.

I would certainly recommend buying bulbs from recognised brands such as Philips, I would also recommend [url= http://www.megamanuk.com/products/led-lamps/reflector/gu10/141401/ ]Megaman's 6Watt LED's[/url], have fitted quite a few of these in retail properties over the last year.

I'm sorry, but that's all I can suggest.


 
Posted : 14/04/2013 7:27 pm
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It may be worth you checking that there is enough free air around the fittings in the ceiling, I.E, no insulation around them.

It's free space. I can see it, I saw the ceiling go in.

Otherwise, thanks for the suggestion. 🙂


 
Posted : 14/04/2013 7:31 pm
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How far is your house from the nearest transformer/substation?


 
Posted : 14/04/2013 7:36 pm
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Cheekyboy- thinking the same thing. Would think that if it's some distance away the volt drop would give high current which the leds won't like. Another possibilty is it's close and you have a voltage in excess of 240v which also isn't good for electronics


 
Posted : 14/04/2013 7:43 pm
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How far is your house from the nearest transformer/substation?

I doubt that has anything to do with it as my mate stays in the arse end of nowhere in galloway and has 52 led downlighters in his kitchen - they've been in for the past year an not a single one has blown despite many sudden powercuts, more than likely it's poor quality led lamps or inefficient heatsinks.


 
Posted : 14/04/2013 8:01 pm
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Have you got a dimmer switch fitted ?

Had a couple of led's blow in the bathroom ...loads of research later & I removed the dimmer switch....problem gone.

The led' s were proper Phillips dimmable units, but the dimmer switch itself was an ordinary dimmer switch & not one specifically designed for led's

Chris


 
Posted : 14/04/2013 9:07 pm
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There was a similar thread on here awhile back but in relation to halogen GU 10s.Have you tried replacing the LEDs with halogen temporarily to see if they blow,that may rule it out as a bulb issue.We have one halogen GU 10 ceiling downlighter out of six that repeatedly blows so we just leave it now,newish rented house.


 
Posted : 14/04/2013 9:19 pm
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I'd bet it's temperature. How hot is the heatsink when they've been running for an evening? The max temp for the LED chip is arounf 100Deg C, so if the heatsink is too hot to keep your fingers on, and it's a cheap design with poor connection from the LED to the heatsink , that would likely be the answer.

Can you not leave one running hanging out of the ceiling? If it's much cooler like that, with space around it, then that might tell you there's not enough airflow. Lastly, you do have the heatsink aligned so the fins are upright don't you?


 
Posted : 15/04/2013 6:49 am
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LED bulbs of 3-6W in fittings designed for 50W halogen bulbs don't get hot. Unscrewing a 5W that's been on all morning it feels pleasantly warm but not hot. I've got 12 LED bulbs of various types that are up to seven years old. One Lidl bulb didn't work out of the box and a Philips failed after a few days; better than any other type of bulb I've used. I reckon it's the make of LEDs you've got, Peter.


 
Posted : 15/04/2013 8:23 am
 mega
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sounds like the bulbs to me - maybe splash out on one of [url= http://www.amazon.co.uk/Long-Life-Lamp-Company-replacements/dp/B006UR5IUY/ref=sr_1_1?ie=UTF8&qid=1366014612&sr=8-1&keywords=gu10+led ]these[/url] for a comparison test while you keep replacing the others through warranty.

I have some and they are great so far - also 3 year guarantee.

Warm white for the kitchen and cool white for bathroom - the cool white is very very bright - like an operating theatre kind of light


 
Posted : 15/04/2013 8:32 am
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LED bulbs of 3-6W in fittings designed for 50W halogen bulbs don't get hot.

Dunno - try it!


 
Posted : 15/04/2013 9:07 am
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It'll be over heating and failing prematurely as a result. Either they're being over driven (poor design) or just getting too hot in their mounts.

Personally I'd not install ones with built in drivers as they take up space and generate heat, so compounding the problem.


 
Posted : 15/04/2013 9:41 am
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Since my last post I've tested a 4W GU10 LED that's been on a few hours and found the hottest bit by touch. It's the glass. I stuck a thermometre on the glass which is currently reading 42°C.

Edit: 44°C - the graduations are 2°C


 
Posted : 15/04/2013 10:35 am
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You really need to know the junction temp in the LED as that's the bit which is dying...

A good rule of thumb is every 10C rise halves the life of electronics.


 
Posted : 15/04/2013 12:30 pm
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Footflaps is correct, though 44 is warm for the heatsink IF the heatsink to junction thermal connection is poor. I'd test one out of the fitting, hanging by the wire below.

If it's h/s is at 20C then there is a significant difference and that may be the culprit. The advantage here is that all this is free to test.

Can you not improve the airflow? is there a hole above the light units to let the warm air escape?


 
Posted : 15/04/2013 12:53 pm
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How do those megaman 6W LEDs compare to 11W CFLs?


 
Posted : 15/04/2013 1:04 pm
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I've said before and I'll say again

http://www.collingwoodlighting.co.uk/cnb/shop/collingwood

Are very nice quality.


 
Posted : 15/04/2013 1:37 pm
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How do those megaman 6W LEDs compare to 11W CFLs?

They would in my opinion, blitz them.

I've said before and I'll say again

http://www.collingwoodlighting.co.uk/cnb/shop/collingwood

Are very nice quality.

First used collingwood stuff in 2009, not suffered one failure in four years, good quality.


 
Posted : 15/04/2013 10:14 pm

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