The Siemens 5SU9336-1CN20 is a 3-pole SENTRON RCBO (residual current operated circuit breaker with overcurrent protection) rated 20 A at 30 °C with a 30 mA residual current trip and Type C tripping characteristic.
The 30 mA residual current trip protects against direct-contact earth faults — the standard for socket-outlet circuits in most IEC-based installations.
Thermal derating in the panel
At 40 °C it derates to 18.6 A, at 50 °C to 17.2 A, and at 55 °C to 16.6 A. If this RCBO sits in a crowded enclosure near other heat sources, size the load to the derated figure — the 75 °C maximum operating temperature is the internal limit, not a free pass to run full current in a hot panel. The unit occupies 6 modular width units (108 mm) on the DIN rail; depth is 77 mm with 70 mm installation depth. Mounting position is unrestricted.
Compliance and approvals
It carries IP20 protection (finger-safe) once installed in a distribution board with conductors connected. The overvoltage category is III, pollution degree 2 — standard for fixed-installation switchgear. Supply can enter from top or bottom, simplifying panel layout.