Siemens 3VA1163-4EF32-0JA0 SENTRON MCCB, 63 A, 121 kA at 240

The Siemens SENTRON 3VA1163-4EF32-0JA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It's rated 63 A continuous at 40 °C ambient — the full-load current it can carry without tripping under normal conditions. The TM240 thermal-magnetic trip unit handles overloads and short circuits, and it includes a shunt trip (STL) auxiliary release for remote tripping via a control signal. Breaking capacity is the headline number here — 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 means it can safely interrupt a fault current up to those levels at the respective voltage without welding contacts or cascading the fault upstream. For a 690 V line, 11.9 kA is still substantial — enough for most industrial motor branch circuits. The current rating holds at 63 A from 40 °C up to 50 °C, then derates linearly: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. If this breaker lives in a hot panel — near a drive cabinet or rooftop enclosure — use the 58 A figure at 70 °C for sizing. The rated insulation voltage is 800 V, so it's comfortable on 690 V systems.