Trip Curve K — what it means for the load
Curve K trips between 8 and 12 times the rated current (160–240 A magnetic pickup at 20 A), bridging the gap between Curve C (5–10×) and Curve D (10–20×). It is sized for inductive loads with moderate inrush — motor starters, transformers, and solenoid valves — where a Curve C might nuisance-trip on startup but a Curve D would be too slow for downstream protection. On a 20 A frame, that magnetic trip threshold sits well above the steady-state draw but still clears a hard short within a half-cycle.
The 2-pole footprint matches the standard modular width (2 × 17.5 mm = 35 mm). No special busbar required for single-phase feed — the line and load side accept fork or pin terminals directly.