Helwig Carbon Products partnered with WEG to design bearing protection kits for their motors, because AC and DC Motors with variable frequency drives (VFD) produce induced electrical currents on the motor shaft. This current seeks the path of least resistance to ground which is typically through the motor bearings. When current passes through the bearings electrical arcs take place leading to fluting, pitting, and bearing damage. The fluted or damaged bearing surface cause noise, vibration, and premature bearing failure. This can lead to costly downtime and lost revenue.
The only good ground is a regularly tested ground. Helwig designed the BPK Probe making it easier for maintenance crews to check the effectiveness of grounding apparatus.