Its interrupting capacity hits 187 kA at 240 V, dropping to 121 kA at 415 V and 440 V, then 75.6 kA at 500 V, and 11.9 kA at 690 V — so it handles serious fault currents on the low-voltage side but you need to check coordination at higher voltages.
The breaker holds its full 400 A rating from 40 °C up to 50 °C, then derates linearly: 392 A at 55 °C, 384 A at 60 °C, 376 A at 65 °C, and 367 A at 70 °C. That matters if this sits in a hot panel next to drives or transformers — you lose about 2% per 5 °C above 50 °C. Maximum power loss is 94.6 W, so plan for heat dissipation in the enclosure.
Dimensions are 184 mm wide, 248 mm tall, and 110 mm deep — a standard 4-pole MCCB footprint for Siemens SENTRON 3VA frames. It mounts into a panel via the rear mounting plate; no DIN rail here, so factor in drilling and bus-bar connections. The undervoltage release (UVR) is pre-installed, which means one less wiring step during commissioning — just connect the control voltage.