The Siemens 5SM3346-0LB01 is a 2-pole SENTRON residual current circuit breaker (RCCB), type AC, with a short-time delayed design. It's rated at 63 A continuous current and trips on a 30 mA residual fault current — the standard sensitivity for personnel protection in most residential and light commercial panels. The 10 kA short-circuit current rating (SCCR) tells you it can safely interrupt a fault current up to that level at 230 V AC without welding its contacts or cascading failure upstream — that's the standard for downstream distribution boards in a 10 kA installation.
DIN rail fit and panel integration
The IP20 rating applies once the distribution board is installed with conductors connected — meaning it's protected against finger contact from the front, but the panel enclosure itself provides the environmental seal. Operating ambient range is -5 °C to 45 °C, with storage from -40 °C to 75 °C; the -5 °C floor is worth noting if the panel sits in an unheated space — below that, the internal mechanism may not trip reliably.