What this RCBO is and what the ratings mean
The Siemens 5SU9356-7CN16 is a combination residual current circuit breaker with overcurrent protection (RCBO), single-pole plus neutral, rated 16 A with a C-trip characteristic and 30 mA Type A residual sensitivity. The 6 kA breaking capacity (Icn) at 230 V AC means it can safely interrupt a short-circuit fault up to that level without welding its contacts or cascading upstream — sized for standard domestic and light commercial distribution boards where the prospective fault current stays under 6 kA. Type A detection handles pulsating DC residual currents from rectified loads like washing machines, LED drivers, and small VFDs, which a plain AC type would miss. The C-curve (trips at 5–10× In) is the go-to for motor and compressor circuits where a brief inrush shouldn't nuisance-trip the RCD side.
Where it fits in the panel
This is a DIN-rail mount module, 1 module width (18 mm per pole, so 2 modules for the 1P+N form factor). Snaps into any standard TS35 rail inside a consumer unit or sub-distribution board. The neutral connects through the device internally, so no separate neutral bar link needed downstream of this RCBO — it switches and protects both line and neutral.