What the Z characteristic means for your BOM line
Z-curve MCBs trip between 2× and 3× rated current, narrower than a C-curve (5–10× In). That makes the 5SL4320-0RC the right call for protecting control transformers, PLC power supplies, or DC-side semiconductor bridges where a C-curve might not clear a fault fast enough to avoid device damage. If your panel was originally specced around a 5SL4363-7 (20 A, C-curve, SENTRON), the Z-curve here will trip faster on moderate overloads — verify coordination with downstream loads before swapping.
IP20 with conductors connected.