The Siemens SENTRON 3VA1020-4ED36-0HC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 20 A and an interrupting capacity of 121 kA at 240 V. That interrupting figure drops to 75.6 kA at 415 V and 52.5 kA at 440 V, so if your panel's available fault current sits above those numbers at the service voltage, this breaker still clears it safely — selectivity studies need that curve, not just the headline. The TM210 thermal-magnetic release handles overload and short-circuit tripping without phase failure detection or ground fault monitoring; it's a straightforward line-protection device, not a multifunction feeder breaker.
Sizing and thermal derating
This breaker holds its 20 A rating from 40 °C through 50 °C ambient, then derates gradually to 18 A at 70 °C. If the panel runs hot — say, a packed enclosure near a process oven — the 18 A floor at 70 °C means you can still size for a 16 A continuous load without nuisance tripping. The rated insulation voltage Ui of 800 V covers 480 V and 600 V class systems with margin.
Auxiliaries and integration
Two auxiliary switches HQ come fitted (the auxiliary contact version is 2 HQ), and the integrated shunt trip (STL) is ordered separately as 3VA9688-0BL30. No undervoltage release, no communication module, no phase failure detection — this is a basic line-protection MCCB with remote trip capability via the shunt coil. Mounting is standard SENTRON 3VA panel or DIN-rail footprint; IP40 on the front keeps dust out of the mechanism in a typical enclosure.