What it is and what it does
The Siemens 3VA1163-3EF32-0BC0 is a SENTRON 3VA molded case circuit breaker (MCCB) for line protection, rated 63 A continuous current Iu with a TM240 thermal-magnetic trip unit. It's a 3-pole breaker built for distribution panels where you need adjustable overload and fixed short-circuit protection, plus an undervoltage release (UVR) as the auxiliary release. Breaking capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — so it handles high-fault industrial feeds without cascading upstream. Rated insulation voltage Ui is 800 V, giving headroom for 480/277 V or 600 V systems. The TM240 overcurrent release means thermal-magnetic, fixed at 63 A — no electronic adjustability, but reliable for standard motor or feeder protection where you don't need LSIG curves. The UVR drops the breaker on loss of control voltage, which is standard for emergency-stop or undervoltage protection schemes.
Ratings that matter for fit
Continuous current holds 63 A from 40 °C up to 50 °C ambient, then derates to 60.48 A at 55 °C and 56.7 A at 70 °C. If your panel runs hot, that derating curve is the real limit — not the 63 A nameplate. Mechanical endurance is 15,000 operations — the latching endurance, not the electrical load-break count. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. The front face carries IP40 protection — fine for a dry indoor panel, but not for washdown or outdoor exposure without an enclosure. Dimensions: 130 mm height, 76.2 mm width (3-pole), 70 mm depth.