The SKF TKED Detection Device (EDD Pen) is an easy-to-use handheld device to detect spark erosion in electric motor bearings. Spark erosion is caused by voltage discharge between the drive shaft and earth through the roller bearing. This leads to electrical erosion and impairment of the lubricant and ultimately to the failure of the rolling bearing. Electric motors with variable frequency drives are much more susceptible to spark erosion in rolling bearings. As part of a condition-based maintenance program, rolling bearings at risk of continuity can be identified using an EDD pen, thus preventing unplanned machine downtimes.