63 A MCCB with 121 kA breaking capacity at 240 V
The Siemens SENTRON 3VA1063-4ED32-0KH0 is a 3-pole molded case circuit breaker rated for line protection, carrying a continuous current Iu of 63 A at ambient temperatures up to 50 °C. Above that, it derates: 60.48 A at 55 °C, 59.22 A at 60 °C, 57.96 A at 65 °C, and 56.7 A at 70 °C — so if your panel runs hot, you lose about 10 % headroom by the time you hit 70 °C. The interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. That 121 kA figure at 240 V means it can safely clear a bolted fault on a high-capacity transformer secondary without the arc flash escalating upstream — a real consideration for main or feeder duty in a distribution panel.
Panel fit and environmental limits
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. The width is a standard 3-pole MCCB footprint — it will drop into a panel designed for a 3VA1010 frame without rewiring, since the mounting centres and bus-bar pitch are identical across the 3VA platform. Front-face protection is IP40, meaning tools and fingers stay out but it is not sealed against hose-down. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Latching endurance is rated at 15 000 operations — that is the mechanical life for the switching mechanism, not the electrical endurance under load. For a line protection breaker that cycles infrequently (a few times a year for testing), that is ample; for a switching duty cycling daily, it is not the right part.