So why did this bearing Fail?
It is a cylindrical roller bearing from the drive end bearing of a 3 phase Induction Motor on a VFD.
Clues in the video here
First correct answer wins a gift from Myles’ desk
October Brain Teaser
Reliability knowledge Now
Moisture in the lube
Uninsulated bearing (fluting)
Electrical fluting caused by leakage current from the VFD. The motor either doesn’t have grounding rings or they are so dirty that it created a conductive path to the bearings.