RCBO with Type A residual current and C-characteristic overcurrent
The Siemens 5SU9346-7CN40 is a combined residual current circuit breaker with overcurrent protection (RCBO) rated Icn 6 kA, 1P+N, Type A, 30 mA, C-Char, In 40 A, Un AC 230V. This means it protects a single-phase 230 V final circuit against both earth leakage (30 mA Type A detects pulsating DC and sinusoidal AC fault currents) and overload/short-circuit (C-curve trips at 5–10× In, so a 40 A unit holds motor inrush but clears fast on a hard fault).
Panel integration note
Mounts on standard DIN rail in the distribution board. The 1P+N format occupies one modular width (typically 18 mm per pole).