The Siemens SENTRON 3VA1063-4ED42-0JC0 is a 4-pole molded case circuit breaker rated 63 A at 40 °C, designed for line protection. Its 121 kA breaking capacity at 240 V AC means it can safely interrupt high-fault currents on a 240 V distribution bus without upstream cascading — critical for panel coordination studies.
Rated breaking capacity drops as voltage rises: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That 11.9 kA floor at 690 V is the limiting figure for a 690 V panel — verify your available fault current at that voltage before specifying.
Full 63 A rating holds from 40 °C up to 50 °C. Above that it derates: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. If your panel ambient runs 60 °C, you lose 2 A — plan the load margin accordingly. Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.