What this MCCB is and what it does
The Siemens 3VA1112-5EF32-0CA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — meaning it sits upstream protecting feeders and distribution from overloads and short circuits, not as a motor-protective device. It's a 3-pole unit rated for 125 A continuous current at 40 °C, and the TM240 thermal-magnetic release handles the trip curve without external power. Breaking capacity is the headline number here: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and still 17 kA at 690 V. That's a high-interrupting rating — it clears serious fault energy without the arc climbing upstream. The rated insulation voltage sits at 800 V, so it's comfortable on 480 V and 600 V class systems with headroom.
Thermal derating and real-world current
This MCCB holds its full 125 A rating from 40 °C up to 50 °C. At 55 °C it's 120 A, at 60 °C it's 117.5 A, at 65 °C it's 115 A, and at 70 °C it's 112.5 A. If the panel runs hot — say near other breakers or a transformer — that derating curve tells you exactly what you can pull without nuisance tripping. No guesswork. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. The IP40 front protection means it's fine in a clean indoor panel; keep it out of washdown zones.
Lifecycle and sourcing reality
It carries an undervoltage release (UVR) as standard — the auxiliary trip specified is 3VA9608-0BB24. No communication module, no ground-fault monitoring, no auxiliary contact version on this variant. If you need those, this isn't the order code.
Panel fit and dimensions
The 3VA1112-5EF32-0CA0 measures 130 mm high, 76.2 mm wide, and 70 mm deep. That width is a standard 3-pole MCCB footprint for SENTRON — it fits existing busbar and DIN-rail layouts without panel rework. The depth of 70 mm leaves room for rear connections and cable bending radius in a 200 mm deep enclosure.