The C63H31M500 is a Schneider Electric ComPacT NSX630H molded-case circuit breaker (MCCB) with a 500 A electronic MicroLogic 1.3 M trip unit, designed specifically for motor protection in three-phase AC networks. It's a 3-pole unit rated for 500 A at 65 °C, meaning it's sized for a motor load drawing that full current continuously in a warm panel — no derating guesswork at standard ambient. The MicroLogic 1.3 M trip unit is electronic, not thermal-magnetic. That matters for motor starting — it gives you adjustable short-time and instantaneous protection (S and I curves per the spec), so you can set the trip point above the inrush without losing coordination downstream. Category A utilization means it's not intended for current-limiting duty; it's a standard-break device for distribution and motor circuits.
Front connections top and bottom, with a 45 mm connection pitch, so busbar or cable lugs land cleanly on the line and load side. IP40 front face keeps accidental tool contact out; IK07 impact rating means it survives a knock during panel assembly.
The interrupting rating varies with system voltage, which is typical for an MCCB. At 240 V AC it's 100 kA Icu; at 415 V AC it's 70 kA; at 440 V AC it's 65 kA; at 500 V AC it's 50 kA; at 525 V AC it's 35 kA; and at 690 V AC it's 20 kA — all per IEC 60947-2. For UL 60947-4-1 applications, it's rated 85 kA at 240 V AC, 65 kA at 480 V AC, and 20 kA at 600 V AC. That's a wide voltage range, so it fits 400 V class and 480 V class systems without needing a different frame.
Durability and environmental limits
Mechanical durability is 15,000 cycles; electrical durability depends on the load — 8,000 cycles at 440 V at half-rated current, 4,000 cycles at full rated current, and 2,000 cycles at 690 V at full current. That's solid for a motor-protection breaker in a machine that cycles a few times per shift.