LED lighting is growing fast as customers buy into the benefits. At the same time, luminaire manufacturers are being pushed to provide longer warranties with fewer operating conditions.
The driver is typically the most complex part of an LED luminaire and the most critical component upon which a warranty is built. Research has shown that most luminaire failures can be attributed to the driver. But in the race to reduce costs, driver lifetime is often misrepresented.
Should failures begin to occur early, and manufacturers start to read the small print, they may find they don’t have the comeback they expect on the driver supplier. This is not helped by the fact that there is no industry standard yet published on LED driver testing, nor is there a standard datasheet format or a rigorous checklist for driver manufacturers to follow.
The lighting industry needs to wake up to this ticking time bomb and challenge driver manufacturers to lift the lid"
The lighting industry needs to wake up to this ticking time bomb and challenge driver manufacturers to lift the lid. Lighting manufacturers need to take a ‘don’t trust the datasheet’ approach. Be wary. Ask questions. Perform your own tests.
Check the conditions under which lifetime guarantees and warranties are made. Is the lifetime given in hours (of continuous operation) or in years (based on an average use per year)? Is it stated at full load, over the entire power range? What about operating temperature?
The biggest threat is heat. Check whether the stated lifetime on the datasheet is at maximum case temperature. If not, look for the graph that shows how lifetime decreases as temperature rises above ambient.
Look for products that provide surge protection, short and open circuit protection and overload protection.
There are many other factors to be considered, but lifetime at what operating temperature is the most critical of all.
Will Gilbert was formerly lighting solutions product manager at Solid State Supplies