Intelligent Power Today Magazine

Although it is now common knowledge that inverters—also known as variable frequency drives—often induce unwanted motor shaft voltages, many customers who purchase three-phase alternating current (AC) induction motors do not realize that models labeled “inverter-duty” or “inverter-ready” might not prevent inverter-caused bearing damage. While many such motors have inverter-rated insulation to protect their windings, their bearings are too often ignored. If they are to be truly ready for use with inverters, these motors also need...