The C63F31M500 is a Schneider Electric ComPacT NSX630F three-pole molded-case circuit breaker with a MicroLogic 1.3 M electronic trip unit, rated 500 A at 65 °C.
At 480 V AC under UL 60947-4-1 it holds 35 kA Icu, so it crosses the Atlantic without derating much. The MicroLogic 1.3 M adds short-time (S) and instantaneous (I) protection — the S band lets you coordinate with downstream starters for selective tripping on a bolted fault.
The 140 mm width, 255 mm height, and 110 mm depth fit standard MCC bucket cutouts. Front connections top and bottom with a 45 mm connection pitch — matches the usual bus-bar tap spacing on a 400 A to 630 A MCC section.
Electrical durability and power dissipation
Mechanical endurance is 15,000 cycles. Electrical durability at rated current (In) at 440 V is 4,000 cycles; at half-rated current (In/2) it doubles to 8,000 cycles. That's typical for a 500 A frame — enough for a motor starter duty cycle of a few operations per hour over a decade. Power dissipation per pole is 25 W, so at 500 A three-pole load the breaker dumps about 75 W into the enclosure — factor that into the panel's thermal budget if it's densely packed.