What this 20 A MCCB delivers
The Siemens SENTRON 3VA1020-4ED32-0AF0 is a 3-pole molded case circuit breaker rated for 20 A continuous current at 40 °C through 50 °C, with a TM210 thermal-magnetic release for line protection. Its interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that matter when coordinating downstream with a transformer or a motor branch that can dump serious fault current. The 800 V rated insulation voltage means it handles 480 V delta or 600 V wye panels without derating the dielectric. The thermal curve holds 20 A flat through 50 °C; above that it tapers to 18 A at 70 °C. That's a 10 % reduction across a 20 °C rise — typical for a 3VA frame, but worth checking if your panel ambient runs hot. The 15 000-cycle latching endurance aligns with the SENTRON line's mechanical life for a 20 A frame.
Mounting and integration
The 3VA1020-4ED32-0AF0 fits a standard 3-pole MCCB footprint: 76.2 mm wide, 130 mm tall, 70 mm deep. It mounts to a DIN rail or panel-mount baseplate. The IP40 front protection keeps dust out of the trip-indicator window and the 1 auxiliary switch + 1 trip alarm switch HQ contact block. No undervoltage release, no ground-fault module, no communication function — this is a straight thermal-magnetic line-protection breaker with a basic auxiliary contact set.