The Siemens 5SU9356-7CR20 is a 1P+N RCBO combining overcurrent protection and residual current detection in a single DIN-rail module. The C-curve means it holds through motor inrush and moderate transformer energization but trips fast on a hard short — standard for mixed resistive-inductive loads in final subcircuits. Type A detection catches pulsating DC fault currents from electronics and rectified loads, not just pure AC sine-wave faults.
Snap-on DIN rail mount, 1 module width (18 mm). The 1P+N topology switches the line conductor and disconnects the neutral internally — no separate neutral bar needed downstream of the device. Rated Un 230 V AC, so it fits single-phase final circuits in TN or TT earthing systems.