The Siemens 5SU9354-7KK50 is an RCBO — a combined RCD and MCB in one 2-module-wide package. Rated 50 A at 30 °C, it trips on both overcurrent (C-curve, magnetic release at 5–10× In) and residual current (30 mA, Type A, so it catches pulsating DC faults from electronics as well as sinusoidal AC).
At 40 °C it derates to 47 A, at 45 °C to 45.5 A, at 50 °C to 43.5 A, and at 55 °C to 40.5 A. If the panel runs warm — say, a crowded DIN rail in a sealed enclosure — factor those numbers into the load calculation. Mounting position is any; the unit can go in horizontally or vertically without derating the thermal trip. Operating frequency is 50/60 Hz, supply voltage frequency 50 Hz.