Is Lumen maintenance rate the only parameter that determine the lifetime of LED lamps? Normally, LED lights are composed of dimmers, power supplies, LED modules, drive components and cooling sections. These modules are connected in series or in parallel within the lamp body. Each module has its own function and reliability. The fault of anyone of them will cause the failure of the entire lamps. Just like the short board effect, the shortest board determines the capacity of the bucket. The one with the shortest lifetime among these modules will determine the service life of the lamp, totally different with traditional incandescent lights. If we treat LED lamps as electronic products, which parts are usually the main reasons for the failure of the lamp?
Common failures of LED lights include: unreasonable cooling section designs, over-load applications, faults of driver circuits, power supplies’ failures and bad components or compartments. Failures frequently happed on electronic appliances will also occurred on LED Panel Lights. These defects can be solved via the laboratory reliability tests for electronic appliances. Another failure is usually caused by the defect of electrical characteristics. Take LED lamps for example, defects of electrical characteristics include: the lumen maintenance rate, color temperature variations, shift of power parameter offsets, etc.. Environmental reliability tests are more accurate for these defects. Therefore, from the past experience of reliability tests for electronic products, LED lighting products should also follow the traditional environment and reliability tests designed for electronic products to verify their reliability and service life.
As the new-born 4th generation lighting source, LED has just been touched or used in many countries and regions all over the world. Thus, it is not easy to find a large number of fault data of them. A recent large-scale failure data happened in Ellwood City, Pennsylvania, in the eastern United States. According the statistics, among the failure records of 5400 pieces outdoor LED lighting applications currently used in Ellwood City, 59% is caused directly by faults of power supplies/drivers, 31% is caused by insufficient heat dissipation, 10% caused by bad LED components. Thus, for outdoor LED products, environmental simulation tests and service life tests are more important. Only take the lumen maintenance rate into account will bright about huge errors.