The Siemens 5SV3347-6KK12 is a SENTRON 5SV3-series residual current circuit breaker (RCCB) — 4-pole, Type A, rated 80 A at 40 °C and 400 V AC. It carries a 10 kA short-circuit current rating (SCCR) per IEC/EN standards, so it safely interrupts fault currents up to that level without upstream damage. The Type A designation means it detects both sinusoidal AC fault currents and pulsating DC fault currents up to 6 mA — common in circuits with rectified loads like VFDs, switching power supplies, and single-phase drives.
What the ratings mean for fit
The 80 A rating is at 40 °C ambient; above that, the device derates linearly — 77.57 A at 45 °C, 74.59 A at 50 °C, 70.22 A at 55 °C, 64.47 A at 60 °C, 57.35 A at 65 °C, and 48.84 A at 70 °C. If your panel runs warm (say, 50 °C inside the enclosure), the continuous load must stay under 74.59 A. The conductor range accepts solid or stranded from 0.75 mm² up to 35 mm² — covers most branch-circuit wiring from 1.5 mm² through 10 mm² comfortably. The 70 mm depth and 72 mm width (4 width units on DIN rail) mean it occupies four 18 mm module spaces; verify your rail has room before pulling the old unit. Mounting position is any orientation, and the supply can enter from top or bottom — no forced top-feed. The IP20 rating applies once installed in a distribution board with conductors connected; it is not rated for washdown or outdoor exposure without an enclosure. Overvoltage category III means it is suitable for fixed installation downstream of the main distribution board.