The Siemens 5SU1324-6KX32 is a 2-pole RCBO (residual-current circuit breaker with overcurrent protection) from the SENTRON family, combining a Type B MCB and a 30 mA residual-current device in one 3-module-wide (54 mm) package.
Thermal derating — what the numbers mean in a real panel
The 32 A rating holds at 30 °C ambient, but drops to 30.4 A at 40 °C and 24.64 A at 70 °C. The derating curve is published, so you can size it properly at the design stage rather than chasing nuisance trips in the field.
The 54 mm width (3 modular units) means it occupies three 18 mm slots; plan your rail fill accordingly if you're retrofitting into an existing board.
