The Siemens 5SU9306-1KK32 is a SENTRON RCBO — an RCD-operated circuit breaker combining overcurrent and residual-current protection in a single 1-module-wide (18 mm) package. For circuits with electronic loads (VFDs, LED drivers, UPS), a type A or F RCBO would be needed; this unit is suited for conventional resistive and inductive loads.
The 5SU9306-1KK32 occupies one modular width (18 mm) with a depth of 77 mm and a required installation depth of 70 mm. Supply can enter from either top or bottom, which simplifies busbar routing in crowded enclosures. The IP20 rating is typical for enclosed distribution boards — the protection applies once conductors are connected and the board is closed.
Thermal derating and environmental limits
Rated current is 32 A at 30 °C, but derates to 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 (–). In a warm cabinet or high-ambient installation, the effective continuous current is lower than the nameplate 32 A — plan the load accordingly. Degree of pollution 2 and overvoltage category III confirm suitability for fixed-installation distribution boards.