The Siemens 5SU9336-1CR50 is a 3-pole RCBO combining overcurrent protection and residual current detection in a single DIN-rail mounted device. It is rated for a 6 kA breaking capacity at 400 VAC, with a C-curve trip characteristic and a 50 A rated current, plus 30 mA type AC residual current protection. This unit sits in a standard distribution board or sub-distribution panel, consolidating two protective functions into one module width.
What the ratings mean for fit
The 6 kA breaking capacity (Icn) at 400 VAC is the short-circuit current the device can safely interrupt — sized for domestic and light commercial final circuits where the prospective fault current stays under that threshold. The C-curve (C-Char) means the magnetic trip operates at 5 to 10 times In (250–500 A for this 50 A unit), suited for circuits with moderate inrush like small motor loads or banks of fluorescent lighting. The 30 mA type AC residual sensitivity detects sinusoidal AC earth faults only; it is the standard choice for general-purpose socket-outlet and lighting circuits, not for pulsating DC fault currents from electronics or variable-speed drives.