What the ratings mean for fit
The 5SU9356-7CN25 is a single-pole-plus-neutral RCBO (residual current circuit breaker with overcurrent protection) rated 25 A, C-curve, with a 30 mA Type A residual-current trip and a 6 kA breaking capacity at 230 V AC. The C-curve (5–10× In magnetic trip) suits it for mixed resistive and moderate inductive loads — lighting circuits, small motor starters, socket outlets in commercial or residential final subcircuits. Type A residual-current detection covers pulsating DC fault currents from rectified loads (SMPS, LED drivers, VFDs) that a plain Type AC would miss. The 6 kA Icn is the short-circuit breaking capacity per EN 61009; it safely interrupts a fault up to that level without upstream backup, provided the prospective fault current at the installation point does not exceed 6 kA.