The Siemens 5SU9306-1KK06 is a SENTRON 5SU9-series RCD-operated circuit breaker — an RCBO that combines overcurrent protection and residual current detection in a single 18 mm wide module. It is rated 6 A with a C tripping characteristic and a 6 kA breaking capacity per EN 60898 (also 6 kA per IEC 60947-2), making it suitable for protecting final circuits against both overload/short-circuit and earth faults in a single unit. The 1P+N configuration switches the phase and monitors the neutral; the Type AC fault-current detection handles sinusoidal AC residual currents.
The 6 A rated current at AC is the continuous load it can carry in a 30 °C ambient. Above that, the device derates linearly: 5.64 A at 40 °C, 5.46 A at 45 °C, 5.22 A at 50 °C, and 4.86 A at 55 °C. If your panel ambient runs at 45 °C, the usable current drops to 5.46 A — plan your load accordingly. The energy limiting class is 3, which means it restricts let-through energy under fault conditions — useful for protecting downstream wiring. The 1P+N configuration with one protected pole means the phase conductor is switched and monitored for overcurrent; the neutral is switched but not fused. For circuits with variable-speed drives, LED lighting, or other electronics that generate non-sinusoidal leakage, a Type A or Type F RCBO would be needed instead.
The 5SU9306-1KK06 occupies one width unit (18 mm) on a DIN rail. The supply can enter from either top or bottom, which simplifies panel layout. Mounting position is any, so horizontal rail orientation in a shallow enclosure is fine. Touch protection is built into the design. The product designation per DIN EN 61346-2 and DIN EN 81346-2 is letter code F.