What this MCCB does and where it fits
The Siemens SENTRON 3VA1020-2ED32-0DC0 is a 3-pole molded case circuit breaker (MCCB) rated for 20 A continuous current (Iu) at up to 40 °C ambient, with a thermal-magnetic overcurrent release (TM210) set for line protection — meaning it protects cables and busbars from overload and short-circuit, not motor or generator circuits. Its breaking capacity is 52.5 kA at 240 V AC, dropping to 32 kA at 415 V and 13.6 kA at 440 V — so for a 400 V line you get a solid 32 kA interrupting rating, which covers most industrial distribution panels with sufficient headroom for high-fault transformers. It also ships with two auxiliary switches (HQ type) built in, giving you remote status feedback without needing an add-on module.
Temperature derating and installation notes
At 40 °C and 45 °C this breaker carries a full 20 A; at 50 °C it stays at 20 A; derating starts at 55 °C (19.2 A) and drops steadily to 18 A at 70 °C — so if your panel runs hot, you lose about 10 % of the continuous rating at the top end. Dimensions: 130 mm height, 76.2 mm width, 70 mm depth — standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without surprises.