if an additional input filter is used, it is mounted on the speed controller,and connected directly to the line supply by an unshielded cable. Connection 3 on the speed controller is then made using the filter output cable.
Although there is an HF equipotential ground connection between the speed controller, the motor and the cable shielding, it is necessary to connect the PE protective conductors (green-yellow) to the appropriate teminals on each of the devices.