The Siemens SENTRON 5SM2335-0 is a 3-pole residual current device (RCD) unit, type AC, rated at 63 A with 30 mA sensitivity for 400 V AC systems. This is the add-on RCD module intended to pair with a 5SY series miniature circuit breaker for combined overcurrent and earth-leakage protection in a single assembly.
The 30 mA sensitivity is the standard for personal protection against indirect contact in TN and TT systems — it clears earth faults before they reach a dangerous let-through energy level. The 63 A rated current matches the upstream MCB or the load circuit it protects; this RCD is not a standalone overcurrent device, so it must be series-connected with a 5SY MCB of equal or lower rating. The 400 V AC rated voltage is line-to-line for a 3-phase system, and the overvoltage category III rating means it is suitable for fixed-installation distribution boards, not for downstream socket-outlet circuits (which would be category II).
The IP20 rating applies only when the distribution board is installed and all conductors are connected — this is a panel-interior device, not a field-mounted unit. The 3 MW width and 70 mm depth fit standard 4-module enclosures; check the busbar compatibility with the 5SY MCB it pairs with, as the RCD module shares the same phase busbar interface.