How to suppress common mode in power line carrier PLC equipotential bonding?

Equipotential bonding in power line carrier PLCs suppresses common-mode interference by balancing the potentials of various metal components within the system. All metal casings, shielding layers, and grounding conductors are connected to the same grounding reference point via low-impedance wires to form an equipotential surface. Braided copper tape or flat copper wire with a cross-sectional area ≥4mm² and a length less than 30cm is used for connection. For high-frequency noise, a high-frequency capacitor (100nF) or a ferrite bead PBZ1608A-102Z0T is connected in parallel at the connection point to provide a high-frequency path. On the PCB, digital ground, analog ground, and power ground are connected at multiple points to form a unified ground plane. During system installation, ensure that the resistance between each component and the grounding reference point is less than 0.05Ω. Equipotential bonding limits the common-mode voltage difference to within 1V, effectively suppressing common-mode noise caused by ground loops. Testing has verified that implementing equipotential bonding improves the system's EFT immunity by one level (e.g., from ±2kV to ±4kV).