Shielding and grounding
A typical AFD cable has three conductors, three grounds, and a
shield that runs the length of the cable. The cable ground should be
tied to the motor ground lug, then tied to the ground lug of the AFD
unit or MCC structure on the other end. Placing the ground as close
as possible to the AFD helps reduce the impedance of the ground
path, thereby reducing system common mode voltages. The shield
should only be tied to the ground at one location to eliminate ground
loops, either at the motor or at the AFD.