Integrator note — S202-K20
The ABB S202-K20 is a 2-pole supplemental protector from the S200 series, rated 20 A with a K-Curve trip characteristic and a 6 kA interrupting capacity at 277 V AC. The K-Curve means it holds through moderate inrush — think motor starters, solenoid banks, or transformer primaries — without nuisance tripping, but still clears fast on a hard short.
What the K-Curve means for fit
The K-Curve is the deciding factor here. Compared to a C-Curve peer like the S202M-C20 (same 20 A, same poles, same interrupting rating), the K-Curve holds a wider magnetic trip window — typically 8–12x rated current versus 5–10x for C-Curve. That extra headroom matters when the load is a small motor or a bank of contactor coils that draw a brief surge on pickup. If your panel was spec'd around the S202M-C20 and the loads are mostly resistive or general-purpose, the K-Curve will still work, but you lose the tighter protection a C-Curve gives on lighting or heater circuits. For motor or inductive loads, the K-Curve is the better fit.
Panel integration
Two poles means it occupies two module widths (roughly 36 mm). No busbar adapter needed if you're feeding from a common bus — the S200 busbar system clips directly onto the line side.