The Siemens SENTRON 5SU1656-1KK32 is a 2-pole RCBO (residual current circuit breaker with overcurrent protection) rated 32 A at 30 °C with a C-curve tripping characteristic and 30 mA AC-type residual current detection. It combines overcurrent and earth-fault protection in a single 2-MW (36 mm wide) module, sized for DIN-rail mounting in distribution boards. Breaking capacity is 6 kA per EN 60898 and 15 kA per IEC 60947-2 — the higher figure applies when the device is specified under the industrial standard, giving headroom for fault currents at the panel level. The AC-type residual current element detects sinusoidal AC earth faults only; specify a type A or B variant if pulsed DC or smooth DC residual currents are present on the circuit. Thermal derating is published from 30 °C through 70 °C: at 40 °C the continuous rating drops to 30.4 A, at 50 °C to 28.8 A, and at 70 °C to 24.64 A. For a panel ambient of 45 °C, the usable load is 29.76 A — factor this into the circuit design rather than relying on the 30 °C nameplate.
Mounting and integration
Occupies 2 modular width units (36 mm) on a DIN rail; installation depth is 70 mm behind the panel face, with an overall depth of 77 mm including the front projection. Mounting position is unrestricted — horizontal, vertical, or inverted — which simplifies layout in crowded enclosures. Supply can enter from either top or bottom, and the device is touch-protected per the product feature. Pollution degree 2 and overvoltage category III suit fixed-installation distribution boards in residential or light commercial environments. IP20 applies when the distribution board is installed with conductors connected. Rated for 50 Hz operating frequency only. Halogen-free and silicon-free construction supports use in controlled-atmosphere zones.