Quote Originally Posted by Tonyg View Post
SKF have an interesting article on current through bearings. I have come across it on some large plasma and oxy/fuel machines with a potential difference between the gantry and the rail where you can see it sparking and the bearing gets very hot (and damaged). Caused by a poor earthing connection, a star earth to between the two generally solves the problem.

https://evolution.skf.com/en/prevent...n-in-bearings/
Bookmarked! Worth being up at 0230.