The Siemens 3VA1020-3ED32-0AH0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection — 3 poles, 20 A continuous at 40 °C, with a TM210 thermal-magnetic release that gives fixed thermal and magnetic trip points. The 20 A rating holds flat through 50 °C; above that it derates 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 cabinet you lose about 2 A off the nameplate. Interrupting capacity runs 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 690 V — that 75.6 kA at 240 V means it handles a serious bolted fault on a 240 V distribution bus without the arc flashing upstream.
The 3VA1020-3ED32-0AH0 measures 76.2 mm wide, 130 mm tall, and 70 mm deep — that's a standard 3-pole MCCB footprint for a 20 A frame. Mechanical endurance is rated at 15,000 operations — that's the latching mechanism life, not the electrical contact wear, so it's fine for a distribution board that sees occasional switching, not a motor-starting duty cycle.