What this MCCB delivers — and what it doesn't
The Siemens SENTRON 3VA1112-3EF32-0BA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 125 A continuous at 40 °C through 50 °C with no derating, then stepping down to 114 A at 70 °C. That thermal curve means a panel built for a 125 A feeder in a 50 °C ambient still holds full ampacity — no need to oversize the frame for a warm enclosure. Breaking capacity reaches 75.6 kA at 240 V and 52.5 kA at 415 V, then drops to 11.9 kA at 500 V and holds there through 690 V. For a 480 V distribution panel this breaker clears a 32 kA fault at 440 V — the closest cited point — so size the upstream AIC against the actual system voltage, not the 240 V headline number. The TM240 release is a fixed thermal-magnetic trip unit — no interchangeable rating plugs, no electronic adjustment. That keeps the BOM simple for a dedicated feeder but means you cannot re-range it for a downstream load change without swapping the whole breaker.
Panel fit and wiring constraints
Mounts on a DIN rail or direct-panel bolt pattern. At 70 mm deep and 76.2 mm wide, it occupies roughly the same footprint as a 3-pole SENTRON 3VA1 frame — expect a 130 mm height. The 30.6 W maximum power loss at full load adds heat inside the enclosure; factor that into the thermal budget, especially if the panel is sealed or densely populated. No auxiliary contacts or shunt trip are included (auxiliary contact version: without). An undervoltage release is present, so the breaker drops open on loss of control voltage — fails safe on demand for a process safety loop, but verify the release coil matches your control voltage before wiring.
Lifecycle and sourcing posture
Rated insulation voltage is 800 V, with an operating range from -25 °C to 70 °C and storage from -40 °C to 80 °C. The 800 V Ui means it can be used in 690 V systems where the insulation coordination requires a higher-rated device than the nominal system voltage.