The Siemens SENTRON 3VA1020-4ED32-0AE0 is a 3-pole molded case circuit breaker (MCCB) rated for 20 A continuous current at 40 °C, with a TM210 thermal-magnetic trip unit — fixed thermal, fixed magnetic, no adjustments on the front. It's a line-protection breaker, not a motor-protection or ground-fault device, so it's the right call for feeder and distribution panels where you need a clean, no-nonsense overcurrent cut.
This breaker carries a 121 kA interrupting rating at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. In a 480 V distribution panel with an available fault current of, say, 65 kA, this breaker is comfortably inside its 52.5 kA at 440 V rating — you'd want to confirm the exact system voltage against the table, but the pattern is clear: it's built for high-fault-capacity industrial mains, not light commercial subpanels.
At 55 °C it drops to 19.2 A, then 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. That means in a hot enclosure — say a non-ventilated panel in a foundry or near a furnace — you still get full 20 A capacity until you cross 50 °C. No one's guessing; the curve is published.
The 3VA1020-4ED32-0AE0 measures 130 mm high, 76.2 mm wide, and 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or screw-mount panel layouts. Front IP40 protection means it's fine inside a closed cabinet; no washdown rating on the front, so keep it behind the gland plate.