The Siemens SENTRON 5SU1354-1KK40 is a 2-pole (1P+N) RCBO — a combined residual-current device and miniature circuit breaker in a single 36 mm-wide unit (2 modular widths). The IP20 rating applies once the distribution board is installed with conductors connected; the unit itself isn't sealed against dust or moisture ingress.
Thermal derating — the real-world rating
Above that, the continuous current must be reduced: 37.6 A at 40 °C, 36.4 A at 45 °C, 34.8 A at 50 °C, 32.4 A at 55 °C and 60 °C, 30.8 A at 65 °C, and 29.2 A at 70 °C. Size the upstream protection and load accordingly.
Panel fit and installation
The 90 mm height fits standard distribution board cutouts. Spring-cage terminals accept the usual copper conductors; no special tooling needed beyond a screwdriver for the terminals.