The Siemens 5SV3414-6KL is a SENTRON 5SV3 series residual current circuit breaker (RCCB) — 2-pole, Type A, rated 40 A at 40 °C, for 230/400 V AC 50 Hz systems. Type A means it detects sinusoidal AC fault currents plus pulsating DC fault currents up to 1 kHz, covering most modern electronic loads (switched-mode supplies, variable-speed drives, LED drivers) that a plain AC-type RCCB would miss.
Thermal derating and conductor sizing
The 40 A rating holds only up to 40 °C ambient. Above that, the continuous current must be derated: 38.1 A at 45 °C, 35.59 A at 50 °C, 32.29 A at 55 °C, 28.19 A at 60 °C, 23.3 A at 65 °C, and 17.62 A at 70 °C.
Depth is 70 mm, height 90 mm — fits standard 2-module-wide cutouts in distribution boards. The design is instantaneous (no short-time delay), so it trips within milliseconds on a fault. Finger and back-of-hand safe to IP20 with conductors connected.