What it is and what it does in the panel
The Siemens 5SV3617-6KL is a SENTRON residual-current circuit breaker (RCCB) — Type A, instantaneous, rated 80 A at 40 °C with a 300 mA residual trip threshold. Two-pole, 50 Hz only, and it snaps onto a DIN rail (REG) in any mounting position. The 300 mA trip makes it a common choice for general socket-outlet circuits where a higher leakage threshold is acceptable to avoid nuisance tripping on equipment with natural leakage.
Key ratings and what they mean for fit
The 80 A rating holds up to 40 °C; above that it derates — 77.87 A at 45 °C, 74.77 A at 50 °C, all the way down to 48.2 A at 70 °C. If your panel runs warm, size the upstream breaker for the derated current, not the 80 A nameplate. The short-circuit current rating is 10 kA per the manufacturer, though the IEC 61008-1 and EN 60898 ratings both list 0.8 kA — the higher 10 kA figure is the conditional SCCR with an upstream backup fuse or MCB. The let-through energy (I²t) is 110 000 A²·s, and the surge-current withstand is 1 kA (8/20 µs waveform), so it handles typical lightning-induced surges on a TT or TN-S system.
Mounting and integration
Two modular-width units (36 mm wide, 90 mm tall, 70 mm deep). Supply feeds from top or bottom — no forced orientation. IP20 with conductors connected, so it lives inside an enclosed distribution board, not out in a wet panel. Silicon-free construction, which matters if the board is in a coating or potting environment where silicone outgassing can contaminate contacts.