Diverting shaft currents away from the bearings

Paul Boughton
With energy costs on the rise, energy efficient technologies have become a primary focus across multiple industries. As a result, the use of variable frequency drives (VFDs) has increased significantly due to their ability to effectively match motor speeds to load requirements– making them more energy efficient and able to generate significant energy cost savings.

While VFD systems provide many benefits, they can also contribute to unplanned downtime. By their nature, VFD systems induce high frequency voltages that travel down the shaft seeking a path to ground. These harmful shaft currents will discharge through the motor’s bearings or the bearings of coupled equipment, damaging the bearings and leading to premature bearing failure and expensive downtime.

Various shaft-grounding methods have been developed in an attempt to protect the bearings from premature failure. The latest development in shaft grounding technology is the Inpro/Seal Current Diverter Ring­ (CDR).

Utilising proprietary conductive filaments, the CDR safely diverts shaft currents away from the bearings by providing a low impedance path to ground – extending equipment life and decreasing maintenance. The Inpro/Seal Motor Grounding Seal (MGS) is designed for total bearing protection on severe duty applications; this unique technology protects against stray shaft currents and harmful contamination ingress.

Enter √ at www.engineerlive/ede
Inpro/Seal. Rock Island, IL, US or Glasgow, UK. www.inpro-seal.com

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