The Siemens 3VA2063-6HL32-0BC0 is a SENTRON molded case circuit breaker (MCCB) rated for 63 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. Breaking capacity is the headline here: 242 kA at 240 V AC, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3 kA at 690 V. That 242 kA figure at 240 V means this breaker handles the highest available fault currents on the secondary side of a typical 150 kVA or larger distribution transformer without needing a current-limiting upstream device — it's rated to interrupt a bolted fault at that level and clear it. Panel footprint: 105 mm wide, 181 mm tall, 86 mm deep.
The 63 A rating holds flat from 40 °C to 70 °C ambient — no thermal derating curve to apply inside a warm enclosure. That simplifies the panel builder's job: if the enclosure internal ambient stays under 70 °C, the breaker delivers its full 63 A without a size-up. Power loss is 7.9 W maximum at rated load. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage minimum matters for unheated warehouses in cold climates — the breaker can sit at -40 °C without damage, though it won't be operated there.