Breaking capacity and temperature derating
The 3VA1120-3EF32-0JA0: Breaking capacity is rated at 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — these numbers tell you the maximum fault current the breaker can safely interrupt at each voltage level. For a 20 A frame, that's a high-interrupting rating, meaning it can handle substantial fault energy without welding or rupturing. Thermal derating is published across the operating range: the breaker carries a full 20 A from 40 °C through 50 °C, then drops 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.
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that fits most distribution panelboards and switchgear cubicles. Front IP40 protection means it's splash-resistant from the front but not sealed; install it inside a cabinet or enclosure.