What it is and what the ratings mean
The Siemens SENTRON 5SV3617-6KK01 is a 2-pole residual current circuit breaker (RCCB) in the 5SV3 short-time delayed design, rated 80 A at 40 °C and 230/400 V AC. The Type A fault current sensitivity means it detects sinusoidal AC residual currents plus pulsating DC — the standard choice for circuits with single-phase rectifiers, switched-mode power supplies, or variable-speed drives downstream. The 10 kA short-circuit current rating (SCCR) tells you it can safely interrupt a fault up to that level without welding contacts or cascading damage upstream, which is the figure your panel designer needs for the selective coordination study. The short-time delayed switching (often called 'selective' or 'S-type' in other brands) means it withstands brief surge currents — rated here at 3 kA — without tripping, so nuisance trips from lightning or capacitor-switching transients don't take a feeder offline while downstream MCBs clear a fault first.
Mounting and panel integration
Snaps onto a DIN rail (REG profile), occupies 2 width units (36 mm), and accepts conductors from 0.75 mm² up to 35 mm² — solid or stranded. The 70 mm installation depth matches standard SENTRON modular-device spacing, so it sits flush in a distribution board alongside MCBs and surge arrestors. Any mounting position is permitted, and the supply can enter from top or bottom. The IP20 rating applies only when the distribution board is installed with connected conductors — typical for enclosed panelboards, not for open racks.
Thermal derating — the real-world current
The 80 A rating holds at 40 °C ambient. Above that, the continuous current drops: 77.87 A at 45 °C, 74.77 A at 50 °C, 70.26 A at 55 °C, 64.32 A at 60 °C, 56.96 A at 65 °C, and 48.19 A at 70 °C. If your panel ambient runs at 50 °C — common in a crowded enclosure with drives — you're limited to 74.77 A continuous. The operating ambient range is -25 to +45 °C; storage range is -40 to +75 °C. The I²t value of 110 000 A²s is the let-through energy the device can withstand, relevant for coordination with upstream breakers.
Compliance and approvals
Overvoltage category III — suitable for fixed-installation distribution boards, not just downstream equipment. Finger and back-of-hand safe per the shock-protection classification. The part is assigned function F under DIN EN 61346-2 and DIN EN 81346-2, which is the standard functional designation for residual-current protective devices in industrial schematics. Silicon-free construction matters for applications where silicone outgassing can contaminate contacts or optics (e.g., automotive paint lines or clean-room panels).