BR6

You can see my left finger resting on the broken piece of case. I broke this brand new 10 amp breaker because the screw was very tight and like an idiot I held case and tried to remove screw. It stressed lug, hence broken case. Best hold lug with a plier and loosen screw, this way you can not stress case. This breaker has close to 4 dozen parts! It is greased in several areas and I believe once breaker gets well aged, grease will begin to go away from friction contact area. Turning on breaker really stresses many components and I think that more friction and aged plastic parts that will most likely become brittle, can likely be failure mode. That is trying to turn breaker on. Once it is latched, I think it will be a pretty relaible contact.
Note:
Speaking to B+C about install of their LR3C, they do not like use of switchable breakers, they say they see them with varying resistance contacting and do not recommend their use.
Y8-12-09