The 400 A rating holds at 40 °C, 45 °C, and 50 °C; above that it derates linearly — 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C — so if your panel ambient runs hot, the real continuous capacity is lower than the nameplate number. At 240 V it interrupts 187 kA; at 415 V and 440 V it delivers 121 kA; at 500 V it drops to 75.6 kA; at 690 V it still holds 17 kA. That is a high-interrupting-capacity (HIC) frame — suitable for main or tie positions in switchboards where fault current is high, not just a downstream feeder. The ETU350 trip unit is a basic electronic release — no communication, no voltage trigger, no ground-fault monitoring. The auxiliary trip module inside is order code 3VA9608-0BB11; the basic switch assembly is 3VA2340-5HN32-0AA0. If you need phase-failure detection or a communication module, this variant does not carry them — you would move to a 3VA2 with a different suffix.
Panel integration — what fits where
Dimensions: 110 mm deep, 138 mm wide, 248 mm tall. The storage limit is what governs handling and warehousing — the operating limit is what matters for the panel environment.