SKF says its new line of Shaft Ground Ring Kits was developed as a solution to help prevent bearing failures due to electrical discharge currents, which can occur when variable frequency drives (VFDs) are used to control AC motors.

The kits have been specifically designed for retrofitting on existing IEC frame size industrial electric motors, reducing the need to spend time, effort and cost in replacing the existing bearings.

Other SKF solutions to overcome the effects of electrical discharge currents include SKF INSOCOAT and SKF Hybrid bearings.

SKF Shaft Grounding Rings Kits (TKGR series) consist of a shaft grounding ring and a selection of mounting brackets and fixings to allow them to be fitted to IEC frame motors.

TKGRs are primarily suitable for common applications such as fans, pumps and compressors driven by motors up to 75kW. Depending on the motor power and application, the TKGR’s may need to be used in combination with SKF INSOCOAT or SKF Hybrid bearings.

Compared to non-protected VFD controlled motors, TKGRs help prevent electrical discharge current damage in rolling bearings and protect both motor bearings and the bearings in attached equipment. Designed to be maintenance free, they improve system reliability, helping to avoid motor repair and unplanned downtime.

The SKF Shaft Grounding ring Kit range consists of nine different sizes to suit IEC frame motors with shaft diameters between 28 and 95mm.