We have around 25 MR16 LED lamps, half of which are almost never used, the other half probably average 4 hours per day, or ~1500 hours per annum.
Remember that greens touted this ‘green technology’ to have a life of 100,000 hours. More recently, claims have been moderated to 10,000 to 25,000 hours… but that is a single LED element alone, not a set of them, and it does not include failures of the internal and external drivers. IOW it continues the fraud of green lighting.
Above, the MR16 50mm LED lamp.
Experience is that we replace about 6 per year, and the replacement season has just begun as the temperatures rise with spring. Previous analysis shows that most failures are the internal LED driver, and almost always the single large capacitor fails (LED lighting woes).
Experience shows that Chinese sellers are not to be trusted, and when buying replacements, I order the 12W warm white lamps as they will match the existing pretty much (though colour ages with these things)… but they are closer to 6W on measurement than the claimed 12W.
So, another pack of 10 12W MR16 50mm warm white lamps from eBay arrived… and need to be tested. There will be no “not as described” claims, they are already free because of late delivery (seller lied about the goods being located in Australia, did I mention that Chinese sellers are not to be trusted).
Two tests were made of a sample of three lamps:
- current drawn at 12VDC, and power calculated;
- luminous flux density at 1m which implies the luminous intensity.
One does not usually find specs on no-name Chinese product, but here is an extract from the Philips datasheet for their MASTER LED 6.5-50W 927 MR16 36D Dim CN product.
Maximum luminous intensity is 1320Cd and the lamp is rated at 6.5W. It is probably a nominally 500lm lamp.
The sample of the Chinese no-name 12W MR16 50mm warm white lamps from eBay measured 1250lx @ 1m implying maximum luminous intensity is 1250Cd (slightly less than the Philips part above. The current at 12VDC was 0.45A, power=5.4W… well short of the claimed 12W (did I mention that Chinese sellers are not to be trusted).
Above are calculations for the measured lamps. These appear to be nominal 500lm 36° lamps, overall luminous efficiency towards 100lm/W… which is ok for cheap lamps.
So, they checkout ok… they are a fraud, but the match the existing lamps that were sized experimentally to provide acceptable luminous flux density.