Shaft voltage induced predominantly by operation of electric motors on variable frequency drives (adjustable speed drives) creates an environment where electrical discharge current can flow through the bearing. This intermittent current flow can create arc pits that damage the bearing’s internal surfaces and lubrication, causing electrical erosion. A solution to this phenomenon is NSK deep-groove ball bearings with ceramic balls, called ceramic hybrid bearings. These specialty bearings offer protection from current flow through the bearing by using the exceptionally high electrical insulating properties of ceramic balls to create a high resistance barrier between the bearing’s steel rings.