Siemens 5SU9326-7CR20 RCBO, 6 kA, 1P+N, 30 mA, 20 A

The Siemens 5SU9326-7CR20 is a residual current circuit breaker with overcurrent protection (RCBO) in a 1P+N form factor, combining a 20 A C-curve MCB with a 30 mA Type A RCD in a single DIN-rail module. The Type A trip characteristic catches pulsating DC fault currents from rectified loads — think switched-mode power supplies, LED drivers, or variable-speed drives on single-phase 230 V circuits — where a plain AC-sensitive RCD would be blind to the half-wave residual current. The 6 kA breaking capacity (Icn) is the standard domestic and light commercial rating for 230 V final circuits in most European installations; it interrupts a bolted fault up to that level without welding the contacts.