What the ratings mean for fit
The 5SU9356-7CN20: The 6 kA breaking capacity (Icn) means this RCBO safely interrupts a fault current up to 6 kA at 230 V AC — adequate for most residential and light commercial final subcircuits where the prospective short-circuit current is below that threshold. The Type A residual-current detection catches pulsating DC fault currents (common from rectified loads like washing machines, LED drivers, or variable-speed pumps) as well as sinusoidal AC faults, so it is the correct choice for circuits feeding modern electronics. The 30 mA trip threshold provides additional protection against direct contact (personnel protection per IEC 60364). The C characteristic (magnetic trip between 5× and 10× In) means it will hold through motor inrush and capacitive loads without nuisance tripping, while still clearing hard faults quickly.
Where it is used
This RCBO fits a single-pole-plus-neutral DIN-rail slot in a distribution board. It combines overcurrent protection (MCB function) and earth-leakage protection (RCD function) in one device, saving space versus separate units. Common in final circuits supplying socket outlets, lighting, or small appliances where both short-circuit and residual-current protection are required.