The Siemens SENTRON 3VA2163-6HN36-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current, with the full rating held across the entire ambient range from 40 °C up to 70 °C — no derating needed in a warm enclosure. Breaking capacity runs 242 kA at 240 V AC, 187 kA at 415/440 V, 121 kA at 500 V, and 3.7 kA at 690 V — these numbers tell you the fault-current ceiling the breaker can safely interrupt at each voltage level, which drives coordination with upstream gear.
Power loss is a modest 4 W maximum, so heat buildup in a sealed panel is manageable.