The Siemens 5SU9356-7KM06 is a SENTRON 5SU9-series RCBO — an RCD-operated circuit breaker combining overcurrent protection and residual-current detection in a single 2-module (36 mm wide) unit. It protects a 1P+N circuit at 6 A rated current with a C tripping characteristic.
Thermal derating and conductor sizing
The 6 A rating holds at 30 °C ambient; above that, the RCBO derates linearly 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. If the enclosure runs warm — common in a crowded DIN-rail cabinet — factor the actual ambient, not the nameplate. The terminals accept solid or stranded conductors from 0.75 mm² up to 35 mm², which covers most branch-circuit feeds (1.5 to 6 mm² typical for a 6 A load) and leaves room for a heavier incoming tail if looped through.
IP20 with the distribution board installed and conductors connected; finger-safe terminals (touch protection per the feature list) reduce arc-flash risk during panel work. Mounting position is unrestricted, so it can go sideways or inverted if the layout demands it.