The Siemens 5SU1356-1KK16 is a SENTRON RCBO — a combined residual-current circuit breaker with overcurrent protection — in a 1P+N, 2-module-width (36 mm) package for DIN-rail panels. It carries a 16 A rating at 30 °C ambient, with a Type C tripping characteristic (magnetic release between 5 and 10 times In) for moderate inrush loads like small motors or lighting banks. The interrupting capacity is 6 kA per EN 60898 and 15 kA per IEC 60947-2, covering most commercial and light industrial fault levels.
The 16 A rating holds at 30 °C; above that, the continuous current must be derated per the listed curve: 15.2 A at 40 °C, 14.88 A at 45 °C, 14.4 A at 50 °C, 13.92 A at 55 °C, 13.6 A at 60 °C, 12.96 A at 65 °C, and 12.32 A at 70 °C. Rated voltage is 230/240 V AC at 50 Hz. Insulation voltage (Ui) is 264 V, and surge voltage resistance is 4 kV, consistent with overvoltage category III and pollution degree 2 — standard for fixed-installation distribution boards.
Two modular width units (36 mm) occupy the rail.