Voltage Discharge Testing on AC/DC Motors
Bearing damage resulting from shaft currents going to ground through the bearing has become more and more common, especially with the increasing use of variable frequency drives.
The best measurement to identify bearing shaft currents is taken with a ScopeMeter. While the motor is in operation, a probe is placed on an exposed area of the motor shaft that gathers the shaft voltage data for analysis.
Both DC and AC motors can be plagued by bearing shaft currents. When going to ground through the bearing, these shaft currents can be harmful causing the raceways to become seriously frosted, fluted and then spalled.
L&S Electric’s Reliability Field Service Team can provide on-site analysis of your motors that are capable of producing shaft currents. Not only are potential problems identified, but corrective actions are recommended so that a low-cost repair can be made to prevent bearing failure – often on-site.