Whether they drive the fans and pumps of commercial HVAC systems or the conveyors of industrial production lines, motors controlled by variable frequency drives (VFDs) are vulnerable to electrical bearing damage. A savvy specifier will choose new motors that are already equipped with shaft grounding rings, but for retrofits the new 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 damage and equipment downtime.
Because the kit can test every VFD-controlled motor in a whole production plant, office building, mechanical room, or anywhere else VFD-driven motors are operating, it provides a powerful tool for maintenance personnel and testing contractors — anyone who needs to determine and convince others that a motor is or is not subject to stray shaft voltages great enough to harm motor bearings. The result of a collaboration between Electro Static Technology (EST) and Fluke Corporation and available from both companies, the kit includes a special replaceable probe tip for highly accurate voltage readings on rotating equipment. Designed by EST, this tip is the first of its kind, containing high-density conductive microfibers that ensure continuous contact with a rotating motor shaft. EST manufactures the tip and extension rod that may be held or used with an optional magnetic base, while Fluke makes the 10:1 probe itself and the Fluke 190 Series ScopeMeter portable oscilloscope that displays the voltage waveform and saves the image for reporting.