While VFDs deliver impressive energy savings, they also induce harmful currents on the shafts of the motors they control, the company explains. These currents damage motor bearings, leading to downtime and premature motor failures. The AEGIS SGR shaft grounding rings channel VFD-induced shaft currents to ground. The SGR ring can be installed in the field without disconnecting the motor from coupled equipment. Split-Ring kits are ordered by motor frame size. Standard kits fit NEMA-frame motors with shaft diameters from 0.625 to 3.375 inches and IEC-frame motors with shaft diameters from 19 to 95 millimeters.