The Siemens 5SU9356-1CR06 is a SENTRON RCBO — an RCD-operated circuit breaker combining overcurrent and residual-current protection in a single 2-module-width (36 mm) package. It protects a 1P+N circuit (one protected pole, one switched neutral) at 6 A rated current (30 °C ambient), with a C tripping characteristic for moderate inrush loads like small motors or lighting banks. Breaking capacity is 6 kA per EN 60898 and 10 kA per IEC 60947-2, so it handles typical domestic and light commercial fault levels without cascading upstream.
What the ratings mean for fit
The 6 A rating at 30 °C derates to 5.64 A at 40 °C, 5.46 A at 45 °C, 5.22 A at 50 °C, and 4.86 A at 55 °C — so in a warm panel (say 45 °C) you're limited to about 5.5 A continuous load. The C-curve trips at 5–10× In, meaning it holds through the start-up surge of a fractional-horsepower pump or a bank of LED drivers but clears a hard fault fast. The 1P+N design switches the line and breaks the neutral, but only the line is protected against overcurrent — the neutral pole is switched only, not monitored. That's standard for single-phase final subcircuits in many European and Asian distribution boards. Mounting position is any, so it fits in a horizontal or vertical DIN-rail enclosure without derating. The IP20 rating applies once the distribution board is installed with connected conductors — fine for a closed panel, not for a wet environment. Operating temperature range is -40 to 75 °C, which covers unheated utility rooms and outdoor cabinets in moderate climates.
Panel integration notes
At 2 modular units wide (36 mm) and 77 mm deep (70 mm installation depth), it occupies two standard 18 mm DIN-rail slots. Supply can enter from top or bottom, which simplifies busbar routing in a crowded enclosure. The halogen-free and silicon-free construction matters for clean-room or high-reliability installations where outgassing is a concern — no silicone contamination on contacts or optics downstream.