What it is and what it does
The Siemens 5SU9604-1KK10 is a SENTRON RCD-operated circuit breaker — an RCBO that combines overcurrent protection and residual current detection in a single 1-module-wide (18 mm) device. It is rated 10 A with a C tripping characteristic and a 300 mA Type AC residual current sensitivity, making it suitable for protecting final circuits against both overload/short-circuit and earth faults in residential or commercial distribution boards. The C-curve means it trips between 5× and 10× rated current — designed for circuits with moderate inrush, such as lighting banks or small motor loads. The 10 kA breaking capacity per EN 60898 covers the majority of domestic and light commercial fault levels.
Panel integration notes
Width is 18 mm (1 modular unit), depth 77 mm, height 125 mm. It snaps onto DIN rail in any mounting position. Supply can enter from top or bottom. The IP20 rating applies once installed in a distribution board with conductors connected — standard for enclosed panel use. Rated insulation voltage (Ui) is 264 V, overvoltage category III, pollution degree 2 — typical for fixed-installation switchgear. The 4 kV surge voltage resistance covers the impulse withstand expected at the service entrance.
Thermal derating and ambient range
Rated 10 A at 30 °C ambient; derates to 9.4 A at 40 °C, 9.1 A at 45 °C, 8.7 A at 50 °C, and 8.1 A at 55 °C. Operating ambient range is -40 °C to +75 °C. If the panel runs hot, factor the derating into the circuit design.