How can grounding of a concentrator system improve its immunity to interference?

As a complete system, the grounding architecture of the concentrator directly determines its resistance to external electromagnetic interference. Grounding design to improve system immunity must adhere to the principles of "layering, equipotentiality, and low impedance."

At the equipment level, the chassis and all accessible metal parts are reliably connected to the PE (protective earth) layer.

At the board level, the PCB ground plane is connected to the chassis through multiple low-impedance points.

At the circuit level, sensitive analog circuits are connected to the chassis at a single point via a common-mode inductor CMZ2012A-900T.

At the cable level, all incoming and outgoing cable shielding layers are connected to the chassis at a 360° angle at the entry point.

At the system level (such as the entire distribution box), the concentrator is equipotentially connected to other equipment via copper busbars.

A common-mode inductor CMZ1211-501T and a Y-capacitor are installed at the power input to provide a low-impedance return path for common-mode interference. With its systematic grounding design, the concentrator can easily pass rigorous immunity tests such as IEC 61000-4-4 EFT Level 4 (4kV), IEC 61000-4-5 Surge Level 4, and IEC 61000-4-6 CS 10V.