What it is and what it does
The Siemens 5SU9306-1KK16 is a 2-pole SENTRON RCBO — a residual-current-operated circuit breaker that combines overcurrent protection (C-curve, 16 A) and residual current detection (30 mA, type AC) in a single 1 MW (18 mm) wide module. It is designed for final circuits in residential and commercial distribution boards where both overload/short-circuit and earth-fault protection are required in one device. Rated 16 A at 30 °C ambient, it derates to 15.04 A at 40 °C, 14.56 A at 45 °C, 13.92 A at 50 °C, and 12.96 A at 55 °C — the thermal curve matters if the panel runs hot. The 6 kA breaking capacity per EN 60898 and IEC 60947-2 handles typical domestic and light commercial fault levels. The 30 mA residual trip covers personnel protection (indirect contact) and fire prevention.
Mounting and integration
Snaps onto standard DIN rail (EN 60715). At 18 mm width (1 MW), it occupies one module position. Depth is 77 mm; installation depth 70 mm. Mounting position is any, and supply can enter from top or bottom — no orientation restriction for panel layout. IP20 with connected conductors, suitable for enclosed distribution boards. Touch protection is built in (fingertip-safe terminals). Pollution degree 2, overvoltage category III — standard for fixed-installation final circuits. Halogen-free and silicon-free construction matters for clean-room or corrosive-environment panels.