The Siemens SENTRON 5SM2626-6 is a residual current (RC) unit designed to pair with the 5SL4 miniature circuit breaker series. It is a 2-pole, type A device rated at 63 A with a 300 mA tripping fault current, operating at 230 V AC and 50 Hz. This combination provides earth-fault protection for circuits where the MCB handles overcurrent and short-circuit, while the RC unit adds the residual-current detection in a compact two-module-width package.
Type A residual current detection means the unit trips on sinusoidal AC fault currents and also on pulsating DC fault currents — the kind generated by rectifiers, switched-mode power supplies, and variable-speed drives common in modern panels. The 63 A rating is the continuous current the RC unit can carry at 40 °C ambient; at higher temperatures the rating derates linearly to 50.4 A at 70 °C. The 300 mA sensitivity is a standard for general-purpose earth-fault protection in commercial and industrial distribution boards where nuisance tripping from leakage is a concern. Mounts on DIN rail (REG) in any position, with a 70 mm depth that matches standard distribution-board cutouts.