The Siemens 5SV3314-6BA is a SENTRON 5SV3-series residual current circuit breaker (RCCB) — instantaneous type, 2-pole, rated 40 A at 230 V AC.
Depth is 70 mm, height 90 mm — fits standard 18-module enclosures with room for gland plates. Mounting position is any, so no derating for horizontal or inverted installation. IP20 with the distribution board installed and conductors connected.
Thermal derating — the real-world current limit
At 45 °C it drops to 38.1 A, at 50 °C to 35.59 A, and at 55 °C to 32.29 A. At 65 °C you are down to 23.3 A; at 70 °C only 17.62 A. If the distribution board runs hot — say, a packed enclosure with multiple breakers — the effective current capacity shrinks fast. Plan the load per the ambient curve, not the nameplate.