What it is and what it does
The Siemens 5SU9354-7KK32 is a SENTRON RCBO — a combined RCD and MCB in one 2-module-wide (36 mm) package, designed to protect a single-phase final subcircuit against overload, short-circuit, and earth leakage. It's a 1P+N device, meaning it switches the line conductor and monitors the neutral for imbalance, tripping on residual current instantaneously (no time delay). The Type C tripping characteristic (5–10× In) handles inrush from motorized loads, lighting ballasts, and small transformers without nuisance trips.
Key ratings and what they mean for your panel
Rated 32 A at 30 °C ambient, with a derating curve provided down to 25.92 A at 55 °C — so if your enclosure runs hot, size the upstream breaker accordingly. The breaking capacity is 10 kA per both EN 60898 and IEC 60947-2, which covers most commercial and light industrial fault levels up to that point. Overvoltage category III and pollution degree 2 suit fixed-installation distribution boards. The insulation voltage (Ui) is 264 V, surge voltage resistance 4 kV, and surge current withstand 1 kA (8/20 μs).
Mounting and environment
Snaps onto DIN rail (EN 60715) in any mounting position, 70 mm installation depth, 77 mm overall depth. IP20 rated when installed in a distribution board with conductors connected — so it's for indoor, dry locations only, not washdown areas. Halogen-free and silicon-free construction, rated for -40 °C to 75 °C storage and 95% humidity. Supply can enter from top or bottom.