The Siemens 5SU1356-0KK13 is a 2-pole RCBO (residual current circuit breaker with overcurrent protection) from the SENTRON series, combining a 13 A overcurrent trip with a 30 mA residual-current device in one 36 mm-wide module.
Thermal derating — where the 13 A rating holds and where it drops
The 13 A rating is valid at 30 °C ambient. At 40 °C it derates to 12.48 A, at 50 °C to 11.96 A, and at 60 °C to 11.31 A. At 70 °C the continuous current drops to 10.01 A — roughly 77% of the nominal value. If this RCBO feeds a continuous 13 A load in a 50 °C panel interior, the breaker will nuisance-trip on thermal overload. Size the load or the ambient before locking the BOM.
Mounting and integration into a distribution board
Mounting position is any orientation — no derating for horizontal or inverted fit.