What this MCCB is and where it lands
The 3VA1163-3EF32-0BA0 is a Siemens SENTRON 3-pole molded case circuit breaker designed for line protection — the primary feeder breaker in a distribution panel, not a motor-protective device. It carries a 63 A continuous rating at 40 °C and holds that same 63 A all the way up to 50 °C, then starts a gentle derate: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C (–). So in a warm panel that sees 60 °C inside, you still get 61 A of headroom — not a hard cliff. The overcurrent release is a TM240 thermal-magnetic type, meaning it uses a bimetal for overload protection and a solenoid for short-circuit, fixed at a 240 A magnetic trip threshold. That's a standard choice for feeder applications where you want thermal memory and a predictable instantaneous pickup.
Breaking capacity — what it can interrupt
This breaker's interrupting rating changes with system voltage, which matters when you're tying it into an existing bus. At 240 V it's rated 75.6 kA; at 415 V it's 52.5 kA; at 440 V it drops to 32 kA; and at 500 V or 690 V it holds at 11.9 kA. The rated insulation voltage is 800 V, so the internal clearances are built for 690 V applications — you're not derating the insulation, just the interruption capability. If your available fault current at the panelboard is 65 kA at 240 V, this breaker covers it; if you're on a 480 V system with 25 kA available, the 32 kA at 440 V rating covers that too.
Undervoltage release and physical fit
This unit includes an undervoltage release (UVR) as the auxiliary release — it's the version with a built-in UVR, not a shunt trip. That UVR will trip the breaker if the control voltage drops below a set threshold, which is common in safety circuits or genset transfer schemes where you want the breaker open on loss of control power. The breaker itself is 70 mm deep, 76.2 mm wide, and 130 mm high, so it fits a standard MCCB footprint on a DIN rail or panel-mount base. Max power loss at rated current is 19.8 W — modest heat for a 63 A frame, but if you're packing several in a closed panel, that thermal budget adds up.