Although every dealer tells me that the failure rate associated with this ballast is one of the lowest, I have had a 100% failure rate. The cooling fans that are supposed to keep the ballast cool, are junk! I have spoken with their tech department and was told, 'that they are designed to run without the fan functioning, which is true, but the temperature of outside metal encloser can get hot enough to light a kitchen match! Not good! The ballast has an internal temperature disconnect, which drops the power to the unit when it reaches a certain temperature. When the unit cools, the switch resets, and the whole process starts over again. The unit does not have trouble light to indicate that there is a problem, so the average person wouldn't even know what was going on until whatever they were growing started not growing well or worst, they have a fire