Integrator note — K-curve supplemental protector
The ABB S202-K40 is a 2-pole miniature circuit breaker from the S200 series, rated 40 A with a K-curve trip characteristic and a 277 V AC maximum voltage. Its 6 kA interrupting rating and UL 1077 supplemental protector listing make it suitable for branch-circuit protection in control panels where the upstream device provides the main fault clearing. Mounts on standard DIN rail, so it drops into the same footprint as other S200 series breakers.
What the K-curve means for your load
The K-curve trips magnetically between 8× and 12× rated current (320–480 A for this 40 A breaker). That range is designed for inductive loads — motors, transformers, solenoids — where inrush can exceed 6× but stays below 8×. It avoids nuisance trips on start-up that a B- or C-curve might cause, while still providing short-circuit protection tighter than a D-curve. For a 40 A breaker on a motor branch, the K-curve is a practical choice when the motor full-load current is around 32–36 A and the inrush is under 480 A.
Compliance documentation
Listed as a UL 1077 supplemental protector and CSA 22.2 compliant. The manufacturer typically provides RoHS and REACH declarations on request for this series.