The Siemens 5SM1316-6BA is a 2-pole residual current device (RCD) — a Type A FI protector — rated 63A at 230V with a 30mA trip sensitivity. That 30mA rating is the ground-fault threshold that protects people: it trips when leakage exceeds 30 mA, which is the standard for socket-outlet circuits where hand-held tools or portable equipment are used. The Type A designation means it detects pulsating DC residual currents (typical from rectifier circuits in electronics or variable-speed drives) in addition to sinusoidal AC faults. A standard Type AC RCD would miss those pulses — this one catches them.
The 5SM1316-6BA occupies 2.5 TE (module width units) on a DIN rail — that's about 45 mm of rail space. The 55 mm depth (D=55MM) fits standard distribution boards and enclosures without crowding downstream wiring. It's a straightforward snap-on install for panel builders or maintenance electricians swapping an existing RCD.