Jump to content

Burnt Out Megaman LED GU10


Barney12

Recommended Posts

Nothing more unnerving than detecting the smell of burning. 

Headed to utility room where the smell was strongest, then realised the lights were off.

The Circuit had tripped and I found this:

FB52D667-B065-4586-9661-2B15A62D93F2.thumb.jpeg.26e9a29a0bf59d5552c8d68ad0a7041a.jpegEBCE97DD-6A66-4AF7-8FDE-5B63D3A223AB.thumb.jpeg.9bc67e5664e063ed76ba6ce876d32137.jpeg

 

It had got hot enough to melt the side of the casing and clearly scorched the down light fitting. 

 

Somewhat unerving. I guess there isn’t really much that could burn in a metal fitting but that must have got seriously hot and the smell was very strong!! 

Link to comment
Share on other sites

53 minutes ago, dpmiller said:

surprised it's internal fuse didn't pop first?

 

You would certainly think they have some sort of fuse system to stop that level of catastrophic failure. 

Does @JSHarris have any insight? 

Edited by Barney12
Link to comment
Share on other sites

1 hour ago, Barney12 said:

 

You would certainly think they have some sort of fuse system to stop that level of catastrophic failure. 

Does @JSHarris have any insight? 

 

 

There's no internal fuse on any duds that I've done an autopsy on.  The particular problem with GU10 LEDs is that the driver circuit is in the base and runs warm.  GU10 fittings designed for use with halogen lights are designed to keep the heat in, as halogen lights are more efficient when run very hot.  LED lights hate heat so need a fitting that will allow heat to escape, especially from the base, where the driver circuit is.

 

What then happens is that the base runs hot and over time components start to fail.  The electrolytic capacity on the input smoothing side is especially intolerant to heat and it's life will be drastically shortened by running hot (this it the reason why it's much better to fit PV inverters is a very cool location - keeping they capacitors cools significantly extends their life).  Once the input capacity fails, then there's a god chance that there will be a chain of failure of other components in the using, leading to the catastrophic failure you have seen.

 

To stop this happening again, make for the GU10 filltings are well ventilated and allow the base of the lamp to receive some cooling.  If run cool their life with be significantly extended.

 

As a final note, I don't like GU10 base LEDs for this specific reason - they cram a constant current driver down into the narrow base and will fit into lights that were designed to run hot with halogen lamps.  MR16 12 V lamps look the same from the front, but have the advantage that the driver is remotely mounted, so can be fitted somewhere in the ceiling void where it will get some cooling.

  • Like 1
Link to comment
Share on other sites

3 hours ago, JohnW said:

@JSHarris is there a unit that you would recommend instead of GU10 base LEDs?

 

 

The ones that look nicest in my view are the slim section flush LED panel lights, like these: https://www.brightlightz.co.uk/12-watt-frosted-round-led-ceiling-light-office-panel

 

Alternatively, ordinary 12 V MR16 downlighter fittings work fine with pretty much any 12 V  MR16 LED lamp, like these: https://www.ledhut.co.uk/spot-lights/mr16-led-bulbs.html?fq[base_type]=MR16

 

Worth looking around, though.  I made a test unit up so I could compare different MR16 LEDs and wrote a short test report, attached.

 

MR16 LED test data.pdf

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...