Panel-builder commissioning notes
The Siemens 5SU9356-7KM16 is a SENTRON RCBO — an RCD-operated circuit breaker combining overcurrent and residual-current protection in a single 2-module (36 mm wide) package. It's rated 16 A at 30 °C with a C tripping curve, Type A fault-current sensitivity, and a 6 kA breaking capacity per EN 60898 (10 kA per IEC 60947-2). That 6 kA rating means it's sized for standard final-subcircuit duty in residential or light commercial distribution boards — not for high-fault industrial mains. The Type A detection handles pulsating DC fault currents up to 6 mA smooth DC, so it covers electronics and rectifier-fed loads where a pure AC-sensitive RCD would miss the fault. Wire termination accepts solid or stranded conductors from 0.75 mm² up to 35 mm² — that's a wide range covering 1.5 mm² lighting circuits up to 6 mm² or 10 mm² subfeeds. The 77 mm depth and 70 mm installation depth fit standard 2-module cutouts in SENTRON or compatible distribution boards. Supply can enter from top or bottom, which simplifies panel layout when busbar orientation varies.
Thermal derating and ambient limits
The 16 A rating holds at 30 °C ambient. At 40 °C it derates to 15.04 A, at 45 °C to 14.56 A, at 50 °C to 13.92 A, and at 55 °C to 12.96 A. That's roughly a 0.6 A drop per 5 °C step above 30 °C — a standard thermal profile for a C-curve MCB. If the distribution board sits in a warm plant room or enclosed cabinet, the actual continuous load should be sized against the derated figure, not the 30 °C headline. The operating ambient range is -25 to +45 °C; storage range is -40 to +75 °C.