The SENTRON 5SM9325-0KN is a 2-pole residual current unit (RC unit electronic) rated for 63 A at 230 V AC, 50 Hz, with a 30 mA tripping threshold for AC fault currents. Its instantaneous design means it trips without intentional delay when the residual current exceeds 30 mA — no time-grading for selectivity, so it's a straightforward fit for branch circuits where fast disconnection is the priority, not coordination with downstream RCDs.
The 63 A rating covers the full incoming supply for a sub-distribution board or a high-load single-phase circuit — most domestic RCDs top out at 40 A or 63 A, so this sits at the upper end. Type AC means it detects sinusoidal AC residual currents only; if the downstream load includes electronics, variable-speed drives, or rectifiers that generate pulsed DC fault currents, a Type A or Type F unit would be needed instead.
Panel integration
Width is two modular units (36 mm), leaving adjacent slots for the upstream MCB or main switch. No neutral bar required — the unit switches the neutral internally.