What this 63 A MCCB does on the line
The Siemens SENTRON 3VA1063-2ED36-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current at 40 °C, with a maximum breaking capacity of 52.5 kA at 240 V AC.
This MCCB's interrupting rating drops as system voltage rises: 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V.
Rated 63 A from 40 °C up through 50 °C, then it starts to taper: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. The 76.2 mm width (3 in) and 70 mm depth (2.76 in) fit a standard MCCB footprint on DIN rail or panel-mount; the 130 mm height (5.12 in) leaves room for the undervoltage release module and auxiliary switch stack that ships with this variant.