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Domestic LED lamps: reliability

by sophiecentaur
Tags: domestic, lamps, reliability
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sophiecentaur
#19
Nov27-12, 06:53 AM
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In Australia they have seen the light, you could say.
NascentOxygen
#20
Nov27-12, 08:00 AM
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Quote Quote by sophiecentaur View Post
I have bought just four mains voltage LED lamps, in my life. Three of them have failed. One has failed after only a very few months and is being replaced by the supplier. They claim that these expensive items are supposed to last for tens of thousands of hours. Has anyone else had this problem or have I just been very unlucky?
The two GU10 lamps both have two burned out (?) diodes in them - two elements are brown!.
At a tenner a time, I just wonder whether they are a step too far, too fast for this technology. Or could they just be bad counterfeits?
There are two areas where reliability can suffer: poor quality control of the individual LEDs, and the cheap, badly built transformerless power arrangement that Chinese manufacturers use for the substitute lamp. With multiple LEDs in series to get the required voltage drop, failure of 1 means failure of that whole string.

An alternative arrangement is to have a separate low voltage transformer in the ceiling, and (for optimal efficiency) operate multiple (2 or 4) LED ceiling lamps from that one transformer. This may be optimal efficiency because a typical LED lamp might be 8W, but the typical mains transformer on light loading has heat losses of around 10W. (So there's a hidden 50% efficiency hit right from the start if you allocate 1 transformer per lamp.)

Drop-in LED replacements are even available for the long 4' fluro tubes, over $100 each and bristling with LEDs.

Here's a little light reading (pun intended):
http://forums.whirlpool.net.au/forum....cfm?t=1905803
http://forums.whirlpool.net.au/forum....cfm?t=1951172
http://forums.whirlpool.net.au/forum....cfm?t=1917704
http://forums.whirlpool.net.au/forum....cfm?t=1499905
http://forums.whirlpool.net.au/forum....cfm?t=1156179
skeptic2
#21
Nov27-12, 09:12 AM
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One other possibility I didn't see mentioned here was line transients. The LED lamps may be more sensitive to line transients than either incandescents or CFLs.
sophiecentaur
#22
Nov27-12, 03:46 PM
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Full of info - thanks.
I think I may wait a few years until going for a full LED conversion. But CFLs are not all they're made out to be, either - their lifespan can be unimpressive.
Back to rush lamps and candles, I think.


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