A 4‑Pole RCCB (40–63 A) is a residual-current circuit breaker designed for three-phase systems with neutral, offering comprehensive earth-leakage protection across all four conductors. Rated for currents between 40 A and 63 A, sensitivities typically from 10 mA to 300 mA, and short-circuit breaking capacities up to around 6 kA, it quickly trips (≤ 0.1 s) to prevent electric shock and fire hazards. Featuring DIN-rail mounting, IP20 finger-safe enclosures, test buttons for functionality checks, and compliance with IEC 61008/EN 61008 standards, it ensures full-phase and neutral isolation for safe maintenance in industrial, commercial, or EV-charging applications