LED Light Degradation

[TugboatEng]

Now that LED fixtures have been common for some time, is anyone else having issues with reduced light output over time? How are you managing or planning for this? Install extra fixtures and dial up the dimmer as they fade? We did a round of newbuild boats that were outfitted with linear LED fixtures about 4 years ago. The boat left on charter with a bright and well lit engine room. It came back dingy and dim. I estimate there has been a 25-30% reduction in light output from the fixture. The life is similar to what I see from fluorescent bulbs, fluorescent bulbs are $10 for a pair while LED models can be hundreds of dollars for an equivalent. And the fluorescent bulbs have a better CRI!

 

[EdStainless]

I have addressed this by re-configuring the power supply when new to reduce the power to the LEDs.
This is usually changing one resistor in the feedback.
Overdriving the LEDS will rapidly age them.
And reducing the load on the PS is useful since the majority of failure is not the LEDs or wiring but the power supplies.
It just means that I need to buy larger arrays than I 'need' so that when I turn them down I have the needed output.
And I only by >90CRI lights.

 

[System Protection]

It's an unfortunate problem. I replaced some LED bulbs that were 3 or 4 years old (intermittent use) with the exact same bulb and the difference in light output was huge.

 

[3DDave]

The earliest makers of LED lamp assemblies were worried about LED damage and under-amped them giving them a long, steady output life.

Now they are concerned with making them bright at low cost, so they run them at near maximum amperage.

Bigger units use constant current power supplies; replacing those with a lower current will greatly extend the life even at a small decrease in brightness.

Big Clive on Youtube, an electrician with a good electrical background and an interest in LED fixtures, has a bunch of videos on that subject.

 

[TugboatEng]

I think this is an example of the frog and a pot of boiling water. The boat went on charter and when it came back the change was instantly noticeable. All of the other fixtures we have converted are slowly dimming at the same rate but the change is less noticeable due to seeing it every day.

Now the problem is that what used to cost $10 per fixture and could be done by anyone on the boat now requires replacement of a $500 fixure and they all go bad at the same time.