What this RCCB does on the line
The Siemens 5SV3412-6KL is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SV3 series, rated 25 A at 230/400 V AC, 50 Hz, with a Type A fault-current characteristic. Rated current holds at 25 A from 40 °C through 60 °C ambient; above that, derate to 23.3 A at 65 °C and 17.62 A at 70 °C — a factor to check if the RCCB lives in a hot enclosure.
Supply can land top or bottom; mounting position is unrestricted. IP20 with conductors connected and distribution board installed — fine for enclosed panels, not for washdown zones. Overvoltage category III suits fixed-installation distribution boards.