What it is and what it does
The Siemens 5SU1356-0KV32 is a combined residual current device and miniature circuit breaker — an RCBO — in a single 1+N-pole DIN-rail module. It provides both earth-fault protection (Type AC, 30 mA trip threshold) and overcurrent/short-circuit protection (B-curve, 32 A rated current) in one unit, saving a DIN position compared to separate RCD and MCB. The 6 kA breaking capacity (Icn) is sized for final subcircuits in residential or light commercial distribution boards where the prospective short-circuit current at the point of installation is within that limit. The B-curve (3–5× In) means it trips instantaneously on moderate overloads, typical for resistive and general-purpose loads.
Panel integration and deployment
Snap-on mounting to standard 35 mm DIN rail. The 70 mm depth (D=70mm) clears most enclosure back panels; verify clearance for the outgoing cable entry and the test-button access. The 1+N-pole format switches and protects the live conductor only; the neutral is switched but not protected — common for TN-S and TN-C-S systems where the neutral is bonded at the origin.