Investigation of influence of bearing load and bearing temperature on EDM bearing currents

To detect the worst case and the best case of the bearing operating conditions concerning the magnitude of the high frequency discharge bearing currents (“EDM currents”) and the frequency of electric discharges in the bearings of the small power inverter-fed AC motors, systematic investigations have been performed for three, 4-pole, 1.5 kW squirrel cage induction motors at different speeds, bearing loads and bearing temperatures.