How does the rcd will work on 3 phase?

A Residual Current Device (RCD) in a three-phase system monitors the current flowing through the live conductors and the neutral. If it detects an imbalance, indicating that some current is leaking to the ground (which can occur due to faults), it quickly disconnects the circuit to prevent electric shock or fire hazards. The RCD operates by comparing the current in each phase and the neutral wire, ensuring that the total current entering the system equals the total current leaving. If an imbalance exceeds a preset threshold, it trips the circuit, enhancing safety in three-phase electrical systems.