What this MCCB is and what it carries
The Siemens SENTRON 3VA1020-2ED36-0DA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a TM210 thermal-magnetic overcurrent release — the fixed thermal element and magnetic trip are factory-set, not field-adjustable — and includes an integrated undervoltage release (UVR) that trips the breaker when supply voltage drops below a threshold, which is useful for preventing motor re-acceleration after a power dip or for emergency-stop circuits that need a positive mechanical break.
Rated current and thermal derating
Rated 20 A at 40 °C ambient, and it holds that rating through 55 °C. At 60 °C it derates to 19 A, and at 70 °C it is still 19 A — so in a warm panel (say 50 °C) you get the full 20 A without having to oversize the breaker. The insulation voltage is rated 800 V, which covers 480/277 V and 600 V systems with margin.
Breaking capacity across voltages
Breaking capacity is 52.5 kA at 240 V AC, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. This is a high-interrupting-capacity (HIC) variant for the 20 A frame — it can handle fault currents that would weld a standard 10 kA MCCB on a 240 V secondary. At 690 V the 7.5 kA rating is still adequate for most industrial motor branch circuits, but verify against your transformer's impedance and available fault current.
Physical fit and panel integration
Dimensions are 76.2 mm wide (3 in), 130 mm tall (5.12 in), and 70 mm deep (2.76 in).