What it is and what it does
The Siemens 3VA1163-4GE42-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection. It's a 4-pole unit rated at 63 A continuous, fitted with a TM220 thermal-magnetic trip unit — that's the standard fixed-trip style for general distribution and motor branch circuits. The 121 kA interrupting rating at 240 V gives you serious fault-clearing headroom at the service entrance or downstream in a panelboard. At 415 V it's still 75.6 kA, and at 690 V it holds at 11.9 kA — so it handles the full range of industrial voltages without needing a current-limiting fuse ahead of it.
Ratings that matter for fit
The 63 A frame is thermally rated at 40 °C through 50 °C without derating — at 55 °C it drops to 62 A, at 65 °C to 60 A, and at 70 °C to 58 A. That's a gentle slope, so it's fine in a warm enclosure as long as you account for the last few amps. The TM220 trip curve is thermal-magnetic, not electronic — no adjustment, no communication, no undervoltage release. If you need remote trip or ground-fault monitoring, this isn't the variant; it's a straightforward line-protection breaker for fixed-load panels. Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep — a standard 4-pole MCCB footprint that drops right into a SENTRON 3VA panel or DIN-rail adapter. The front face carries IP40 protection, so it's fine in a clean indoor panel but not for washdown or outdoor exposure.