The interrupting capacity is 6 kA on AC and 10 kA on DC, which covers most branch-circuit fault levels in panelboards and sub-distribution boards.
Trip Curve C means the magnetic trip threshold is 5 to 10 times the rated current — so on a 3 A breaker, the instantaneous trip point sits between 15 A and 30 A. The 6 kA interrupting rating at 277 VAC is standard for residential and light commercial panelboards; the 10 kA DC rating at 60 VDC covers battery-backed control circuits and DC bus protection. Both ratings are tested per IEC/EN 60898 — the standard for MCBs in household and similar installations.