The Siemens 5SM1316-0FD is a Type AC FI-PROTECTOR residual current device (RCD), rated 63A at 230V with a 30mA trip threshold. The 2-pole, 2.5TE-wide unit (55mm) snaps onto a DIN rail for panel integration. Type AC detection handles sinusoidal AC fault currents — the common residential and light commercial residual current profile.
The 63A rated current means this RCD is sized for a main or sub-main circuit feeding a group of loads up to that ampacity — think a small distribution board or a heavy appliance circuit. The 30mA residual operating current (IΔn) is the touch-protection threshold per IEC 60364: it trips when leakage to earth exceeds 30mA, which is below the let-go current that causes ventricular fibrillation. Type AC (sinusoidal AC only) is the baseline classification; for circuits with rectified or pulsed DC fault content (e.g., variable-speed drives, LED drivers, EV chargers), a Type A or Type B device is required instead.