Siemens 5SU9356-7KK32 is a SENTRON RCBO — an RCD-operated circuit breaker combining overcurrent and residual-current protection in one 2-module-wide (36 mm) package.
The 32 A rating at 30 °C is the headline figure, but the real-world capacity drops with ambient temperature: 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. Type A residual detection trips on sinusoidal AC faults and pulsating DC faults up to 30 mA — the standard choice for circuits with single-phase rectifiers or switched-mode power supplies. The 1P+N design protects only the live pole; the neutral is switched but not protected.
Two modular width units (36 mm) snap onto standard DIN rail. Installation depth is 70 mm plus the 77 mm overall depth — check the gland plate clearance if the board is shallow. IP20 only when the distribution board is installed and conductors are connected; handle as a live component during wiring.