What this breaker is and what it handles
The Siemens 3VA1163-3EF32-0AC0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for a continuous current of 63 A, with a TM240 thermal-magnetic trip unit — meaning it combines a bimetal overload element with a magnetic short-circuit coil, no electronics to fail in a hot panel. The line-protection version covers cable and busbar faults, not motor overload curves. 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 — those numbers tell you the maximum fault current it can safely interrupt at each voltage level, so the panel designer sizes the upstream transformer and bus bracing accordingly.
Thermal derating and real-world mounting
The breaker holds its full 63 A up to 50 °C (–). At 55 °C it derates to 60.48 A, at 60 °C to 59.22 A, at 65 °C to 57.96 A, and at 70 °C to 56.7 A. If the panel runs hot — next to a drive cabinet or under a roof in summer — you plan the load at the derated value, not the nameplate. The front face is IP40, so it keeps out tools and fingers but not fine dust; mount it inside a sealed enclosure if the atmosphere is gritty. Dimensions are 70 mm deep, 76.2 mm wide, and 130 mm tall — a standard 3-pole MCCB footprint that fits most DIN-rail or screw-mount panel layouts without re-drilling.
Auxiliary contacts and release options
It ships with two auxiliary switches HQ — those are the signal contacts that tell a PLC or indicator light whether the breaker is open or closed. No undervoltage release, no shunt trip, no ground-fault module. The overcurrent release is the TM240, a fixed thermal-magnetic unit with a maximum adjustable response time of 1 second — not a solid-state electronic trip. Rated insulation voltage is 800 V, which covers 480/600 V systems with margin. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.