Like I said the story I got was that there was a batch of breakers with a known problem and the owners have been notified, thats the letter I want to see.
Read between the lines, 0.04% have been reported, sounds small but how would one know they have a problem unless the clips failed?? You wouldnt, it is not like these breakers are being racked in and out often either, most industrial plants they are hardly ever touched.
Lets say you have a double ended substation with 20 of these breakers, there is a .8% chance you have a known problem, now lets say your large industrial plant has 14 of these substations, 11.2% chance you have a known problem, and again thats only because either the clips failed or you were notified by the manufacture about a known problem with the clips.