The Siemens 5SM3416-6 is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 63 A at 230 V AC, 50 Hz, with a Type A fault-current sensitivity. It carries a 10 kA short-circuit current rating and is designed for instantaneous tripping — no intentional delay, so it responds to earth faults as they occur. This is the part you spec into a sub-distribution board where you need earth-leakage protection for a 63 A outgoing feeder, typically feeding a mixed load with electronic equipment that can generate pulsating DC fault currents (Type A covers that).
The 63 A rating holds at 45 °C ambient without derating; at 50 °C it drops to 59.22 A, at 55 °C to 55.44 A, and so on down to 44.1 A at 70 °C. The I²t withstand is 70,000 A²·s, which tells you the energy it can handle during a fault before the upstream device clears it. The Type A designation means it detects sinusoidal AC residual currents plus pulsating DC residual currents — the kind produced by single-phase rectifiers in switch-mode power supplies, VFDs, and LED drivers. For a panel feeding a mix of resistive and electronic loads, Type A is the standard choice; you only step up to Type B if you have three-phase rectifiers or frequency inverters generating smooth DC fault currents.
Snaps onto DIN rail (REG profile), occupies 2.5 width units (36 mm wide), 90 mm tall, 70 mm deep. Wiring accepts solid or stranded conductors from 1.5 mm² up to 25 mm², which covers the full range for a 63 A circuit (typically 10–16 mm² for the feeder). Supply can enter from top or bottom; mounting position is any orientation. IP20 with the distribution board installed and conductors connected — so it's for enclosed panels only, not open washdown areas.