That 400 A holds from 40 °C up to 50 °C without derating — at 55 °C it's still good for 384 A, and at 70 °C it's 360 A. The breaking capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. The auxiliary release is integrated as 3VA9608-0BB11.
Selectivity and coordination — where the numbers matter
The ETU350 release is adjustable, so you can dial in the I²t curve to coordinate with branch breakers.
It's a 3-pole unit designed for screw-mounting in a distribution panel or switchboard.