How to connect the motion controller MC signal ground to the chassis ground?

The connection method between the signal ground and chassis ground of the motion controller (MC) depends on safety requirements and EMC strategies. For safety grounding, the chassis ground must be reliably connected to the protective ground. There are two common methods for connecting the signal ground to the chassis ground: In floating ground systems, the signal ground is connected to the chassis ground through a high-voltage capacitor, such as a 1nF/2kV Y capacitor, providing a discharge path for high-frequency noise while maintaining DC isolation.

In single-point grounding systems, the signal ground is connected to the chassis ground at the power input through a resistor or ferrite bead. The connection point should be selected at the location with the lowest noise, typically the grounding terminal of the power supply filter capacitor. The connection impedance should be as low as possible, using multiple screws or metal supports. All connections must ensure electrical continuity, with clean contact surfaces and, if possible, the application of conductive paste. The effectiveness of the connection is verified by measuring the impedance and noise voltage at the connection point. The design must comply with relevant safety standards, such as insulation resistance and withstand voltage test requirements.