Shaft Voltage Discharge Testing

Shaft Voltage Discharge Testing. Have you been experience low reliability of motor, pump, fan or gearbox bearings after installing a new Variable frequency Drive- we can help!

What is EDM (Electrical Discharge Machining):

  • The pulses to the motor from the VFD create a capacitively coupled common mode voltage on the motor shaft
  • The voltage looks for a path to ground, breaks down the dielectric in the bearing. The voltages arc through the bearings, and electrical discharge machining (EDM) creates thousands of pits
  • Bearings degrade, resulting in increased friction and noise
  • Eventually, the rolling elements can cause fluting damage to bearing races
  • Bearing lubrication/grease deteriorates, is burnt and fails
  • Potential for costly unplanned downtime

We use the Fluke 190-202 Scope Meter, 200 MHz, 2.5 GS/s. Fluke 10:1 voltage probe. AEGIS® SVP – Shaft Voltage Probe Test Kit to test for VFD induced shaft voltages.

For non-contact assessment we use the SKF TKED1 Electrical Discharge Detector Pen.