What it is and what it does
The Siemens SENTRON 5SU1356-0KK16 is a 1P+N RCBO — a combined residual-current device and miniature circuit breaker in a single 2-module-wide (36 mm) housing. It protects a single-phase final subcircuit against overload, short-circuit, and earth leakage, with a Type B tripping characteristic (instantaneous magnetic release for short-circuits, thermal bimetal for overload). Rated 16 A at 30 °C ambient, it derates to 12.32 A at 70 °C — a curve worth checking if the panel runs hot. Breaking capacity is 6 kA per EN 60898 (the household standard) and 15 kA per IEC 60947-2 (the industrial standard), so it handles fault currents up to 15 kA at 230/240 V AC, 50 Hz. Overvoltage category III and pollution degree 2 suit it for fixed-installation distribution boards in commercial or light-industrial settings.
Mounting and integration
Snaps onto standard 35 mm DIN rail. At 36 mm wide (2 modular width units), it occupies two adjacent slots in a consumer unit or panelboard. Supply can enter from top or bottom; the 77 mm depth (70 mm installation depth) fits standard enclosures. Mounting position is unrestricted — any orientation works. IP20 with conductors connected means it's protected against finger contact once wired inside a closed distribution board.