What this 4-pole MCCB carries
The Siemens 3VA1112-6EF42-0AA0 is a SENTRON 4-pole molded case circuit breaker rated for 125 A continuous at 40 °C through 50 °C, with a TM240 thermal-magnetic overcurrent release. That 125 A holds flat across the 40–50 °C band — no derate needed in a warm panel — then steps down to 122 A at 55 °C and 114 A at 70 °C. Interrupting capacity is the headline: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V. That 220 kA at 240 V means it handles high-fault utility feeds without cascading upstream — useful for main breaker duty in a distribution panel where the transformer secondary is stiff. Design is line protection (not motor or generator protection), so the TM240 release curve is shaped for cable and busbar thermal limits. Insulation voltage rated 800 V, IP40 on the front — fine for a dry indoor enclosure, not for washdown zones.
Panel fit and thermal budget
Dimensions: 130 mm tall, 101.6 mm wide, 70 mm deep. Four-pole width at 101.6 mm (4 inches) matches standard MCCB spacing. Max power loss is 28.1 W. In a sealed panel with multiple breakers ganged, that heat adds up — plan for ventilation or derate if ambient inside the enclosure pushes past 50 °C. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. The 70 °C operating ceiling matches the derate curve top end.
What it doesn't carry
No undervoltage release, no trip indicator, no voltage trigger, no communication function, no ground-fault monitoring. This is a straight thermal-magnetic breaker — no aux electronics. If you need shunt trip or remote status, you're looking at a different variant in the 3VA family.