Thermal derating and panel fit
The 3VA1063-3ED42-0AC0: The 63 A rating holds steady from 40 °C through 50 °C (–), then steps down to 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C (–). That derating curve is flat enough that a panel running at 50 °C ambient still gets full rated current — no oversizing needed for typical enclosed switchgear. The breaker measures 70 mm deep, 101.6 mm wide, 130 mm high (–), a standard SENTRON 3VA frame footprint that drops into existing Siemens panelboards and DIN-rail adapters without re-drilling. Max power loss is 17.3 W, manageable for thermal coordination inside a sealed enclosure.