What this MCCB carries — and where it breaks
The Siemens SENTRON 3VA1120-6EF32-0AB0 is a 3-pole molded case circuit breaker rated for 20 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. Its interrupting ratings are the headline: 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. That 220 kA at 240 V tells you this breaker is built for high-fault-capacity distribution — think transformer secondaries or large busway feeds where fault current can hit serious levels. The TM240 release means the thermal element is fixed at 20 A; no field adjustment on the continuous rating, so the BOM line is locked once specified. Thermal derating is minimal through 50 °C — still 20 A — then drops to 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. In a sealed panel with ambient near 60 °C, you lose about 1.2 A of headroom; factor that into the load calculation if the panel runs hot.
Panel fit — footprint and auxiliaries
Dimensions: 130 mm tall, 76.2 mm wide, 70 mm deep. That 76.2 mm width is a 3-pole MCCB standard — it occupies three 25.4 mm module spaces on a DIN rail or panel-mount grid. The 70 mm depth is shallower than many older-frame MCCBs, which helps in tight gland-plate clearance or when mounting flush in a shallow enclosure. IP40 on the front face; the breaker is not sealed against washdown, so keep it inside a panel, not on the line-side of a washdown zone. Comes with 2 auxiliary switches HP (high-performance) factory-fitted. That means you have two independent signal contacts for status feedback — one for the panel PLC input, one for a remote annunciator or safety chain. No undervoltage release, no shunt trip, no communication module on this variant; it is a straight line-protection breaker with aux contacts only.