What the K-characteristic means for fit
The S201M-K10: The K-curve is the middle ground between B and C curves: it trips magnetically at 8–14× rated current (In), compared to 3–5× for B-curve and 5–10× for C-curve. That means it tolerates the inrush of transformer-coupled loads, motor starters, and inductive solenoids without nuisance tripping, but still clears a hard short fast enough to coordinate with downstream fuses or contactors. For a 10 A pole, magnetic trip kicks in between 80 A and 140 A — high enough to ignore a motor start, low enough to protect the cable.