How to isolate the communication ground and power ground of a power FTU?

Communication ground and power ground are isolated to prevent high-current noise interference. A single-point connection using a ferrite bead is employed: a PBZ1608E600Z0T ferrite bead (600Ω@100MHz) connects the two ground planes, providing high-frequency isolation and low-frequency connectivity. The communication interface uses an isolation scheme: RS485 uses an ADM2483 isolated transceiver (2.5kVrms), and Ethernet uses a LAN8720A with an isolation network transformer. PCB design: the two ground planes are separated with a 2mm spacing, and cross-zone signals use TLP281 optocouplers. This isolation reduces ground noise coupling by 40dB, and the communication bit error rate is less than 10^-6, meeting the IEC 61000-4-6 conducted immunity test requirements.