63 A, C-Curve, 2-Pole — Panel Fit and Breaking Capacity
Breaking capacity is 6 kA per EN 60898-1 and 10 kA per IEC 60947-2 / UL1077 — the higher 10 kA figure governs when the breaker is applied in industrial control panels where the available fault current exceeds residential limits. The dual rating means the same unit qualifies for both commercial and light industrial installations without a separate high-fault variant.
Temperature Derating and Ambient Limits
The 63 A rating holds at 35 °C ambient. At 40 °C the breaker must be derated to 59.16 A; at 50 °C to 55.06 A; at 55 °C to 52.92 A. This derating curve matters when the breaker shares a crowded enclosure with other heat sources — a panel OEM wireman would account for the actual ambient inside the cabinet, not the 35 °C reference point. Operating temperature range is -40 °C to 75 °C, with humidity limits of 95 % RH at 55 °C down to 35 % RH at 75 °C.