The Siemens 5SU9156-7VK32 is a 1P+N RCD-operated circuit breaker (RCBO) from the SENTRON 5SU9 series, combining overcurrent and residual current protection in a single 2-module (36 mm wide) package. The Type A fault current detection covers pulsating DC and AC residual currents — common on VFD-fed equipment, washing machines, and single-phase rectifier loads.
That dual rating means it's accepted in both residential distribution boards and industrial panel builds — the 10 kA figure gives headroom for higher-fault-capacity industrial supplies. The C-curve trips at 5–10× rated current, so it's sized for circuits with a starting surge (small motors, transformers, discharge lighting) rather than purely resistive loads. Current derating is published across ambient temperature: 32 A at 30 °C, 30.08 A at 40 °C, 29.12 A at 45 °C, 27.84 A at 50 °C, and 25.92 A at 55 °C. If the panel ambient runs at 45 °C, the usable load drops to 29 A — factor that into the BOM before sizing the downstream load.
Snaps onto DIN rail in a distribution board or industrial panel — 2 width units (36 mm) means it occupies two adjacent 18 mm slots. Rated IP20 once the distribution board is installed with conductors connected, so it's intended for enclosed use, not washdown or outdoor exposure.