By Adam Willwerth, Electro Static Technology Nearly all VFD-driven motors are vulnerable to bearing damage, but for too long the importance of shaft grounding to protect motor bearings has been ignored or underestimated. To make the savings generated by VFDs sustainable, an effective long-term method of shaft grounding is essential. All major manufacturers of 3-phase…

An inexpensive method of grounding motor shafts to divert harmful VFD-induced currents protects motor bearings, increases motor life, and improves system reliability. With the rising cost of energy, more variable-frequency drives (VFDs) are being installed for motion and speed control. They are highly efficient, but the currents they induce on motor shafts can wreak havoc…