The 5SM3614-0: The 300 mA trip level makes it suitable for whole-circuit ground-fault protection where leakage is expected (cable capacitance, heaters, multiple loads) rather than personnel protection, which typically requires 30 mA. The AC-type detection covers sinusoidal residual currents only.
The 5SM3614-0 carries its full 40 A rating up to 45 °C ambient; above that it derates linearly to 32 A at 70 °C. In a crowded DIN-rail enclosure, consider the internal temperature rise from adjacent breakers and contactors — the derating curve is real and starts at 45 °C. The IP20 rating applies with the distribution board installed and conductors connected — this is a protected-enclosure device, not for open-panel washdown zones. Mounting position is unrestricted, and supply may enter from top or bottom — useful when reworking an existing panel layout without flipping the busbar arrangement.