How can the chassis grounding of the intelligent low-voltage monitoring unit meet EMC requirements?

The chassis grounding meets EMC requirements by providing a low-impedance discharge path. A combination of multi-point and single-point grounding is used. The metal chassis is continuously conductive on all six sides, with beryllium copper springs at the joints, resulting in a contact resistance of less than 15mΩ. The chassis is connected to the grounding stake via a low-impedance copper strip (16mm²), with a grounding resistance of less than 0.2Ω. The internal PCB is connected to the chassis via metal supports. Cable shielding is connected to the chassis via a 360° crimping method. On the PCB, digital ground and analog ground are connected to the chassis via a 100nF/2kV capacitor. This grounding system allows for rapid discharge of electrostatic discharge current, meeting IEC 61000-4-2 Level 3 electrostatic discharge (contact discharge 6kV) and IEC 61000-4-5 surge test requirements.