Originally posted by RoJo:
It seems these capacitors failing are a common problem. Does that mean these calculations are not fool-proof and even manufacturers get it wrong? 
I believe the phase is sh*t happens sooner or later with age something will fail, if nothing failed we wouldn't be in a job.
Then again if the capacitor choosen was not the correct choice it might take years while the capacitor is stressed. Or that stress could come from voltage spikes on mains or external heat.
