The Siemens 5SU1653-7KV32 is a combined residual-current device and miniature circuit breaker (RCBO), known in the catalog as an FI/LS protector. It packs a Type A RCD with a 30 mA trip threshold and a C‑curve 32 A MCB into a single 1+N-POL module, rated for 4.5 kA breaking capacity. That 70 mm depth keeps it flush in standard distribution boards — no need to rework the enclosure door or gland plate.
Type A detection means it catches both sinusoidal AC fault currents and pulsating DC fault currents — the kind you get from single-phase rectifier loads like washing machines, LED drivers, or switched-mode power supplies. The 300 mA IΔN is a fire‑protection threshold, not a personnel‑protection one (30 mA is the touch‑safe level), so this unit is sized for circuits where the main risk is cable insulation degradation rather than direct human contact. That 4.5 kA breaking capacity is the standard domestic and light‑commercial level for EN 60898‑1 installations; if your fault‑current study shows higher prospective short‑circuit current, you’ll need a unit with a higher Icn or an upstream back‑up fuse.
Lifecycle is marked as current — Siemens still lists this as an active catalog number.