What it is and what it does
The Siemens SENTRON 3VA1020-2ED36-0JC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, with a rated continuous current Iu of 20 A and a TM210 thermal-magnetic overcurrent release. Its interrupting capacity reaches 52.5 kA at 240 V and 32 kA at 415 V, dropping to 13.6 kA at 440 V and 7.5 kA at 690 V — figures that define the available fault current it can safely clear at each system voltage level. The TM210 release means the thermal element handles overload protection and the magnetic element handles short-circuit protection; there is no electronic trip unit, so settings are fixed at the factory. It carries a shunt trip (STL) for remote tripping and two HQ auxiliary switches for status feedback, but no undervoltage release, no phase failure detection, and no communication function. Rated insulation voltage Ui is 800 V, and front protection class is IP40 — suitable for installation inside a panel enclosure that provides the environmental seal.
Thermal derating and panel integration
The breaker carries a full 20 A up to 50 °C ambient; above that it derates linearly 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 — so in a warm panel the continuous load must be backed off accordingly. Dimensions are 76.2 mm wide, 130 mm high, and 70 mm deep — a standard 3-pole MCCB footprint that fits common DIN-rail or mounting-plate layouts without surprises. The shunt trip (STL) auxiliary release is ordered separately as 3VA9688-0BL32; if your BOM calls for remote tripping, that order code needs to be added. Electrical endurance is rated at 15,000 operations.