The Siemens 5SU1653-7KV16 is an FI/LS combination unit — an RCD (residual current device) and MCB (miniature circuit breaker) in a single 1+N-Pol module. It carries a Type A residual-current characteristic with a rated residual current (IΔn) of 300 mA, and a C-curve overcurrent trip at 16 A. The interrupting capacity is 4.5 kA. The 70 mm depth (D=70mm) fits standard distribution board cutouts.
What the ratings mean for the panel
Type A detection means it responds to AC sinusoidal residual currents plus pulsating DC residual currents — the typical waveform from rectified loads like switched-mode power supplies, LED drivers, and variable-speed drives. The 300 mA sensitivity is a fire-protection threshold (not personnel protection, which would be 30 mA), so this unit is sized for circuits where the leakage budget is higher and the goal is to prevent cable overheating rather than shock. The C-curve (magnetic trip between 5× and 10× In) handles moderate inrush from motorized loads or capacitive filters without nuisance tripping.