Inverters used to control a motor’s speed or torque — also known as variable frequency drives (VFDs) or adjustable speed drives — can induce unwanted motor shaft voltages that cause premature motor ...

A typical low-voltage variable-frequency drive. Industrial facilities commonly use variable-frequency drives (VFDs) to control the speed at which alternating current motors operate. Let’s examine a ...

Variable-frequency drives, or VFDs, are becoming more commonplace in motor retrofits and new installations. And while they boast increased energy efficiency as the main benefit, a small — but by no ...

All major manufacturers of three-phase ac induction motors offer “inverter-duty” or “inverter-ready” models, but while these motors have inverter-rated insulation to protect the windings, the bearings ...

Electric motors fitted with variable frequency drives are at risk of bearing damage due to a build-up of current in the rotor that discharges through the shaft, damaging the lubrication and bearing ...

A VFD reports a low-volts fault when the drive's dc link voltage drops below 62% of the nominal level for the high setting (480 Vac) and 50% of nominal for the low setting (400 Vac). The +10% and -15% ...

For retrofits Electro Static Technology’s AEGIS® Shaft Voltage Test Kit makes it easier than ever to measure and document damaging VFD-induced voltages while there is still time to head off bearing ...