What makes it interesting for a wind turbine or industrial feeder is the interrupting capacity: 242 kA at 240 V, 187 kA at 415 V, and still 40 kA at 690 V. That kind of SCCR headroom means it survives a bolted fault on a 690 V turbine collector bus without cascading upstream — no up-tower swaps when a short clears cleanly.
Thermal derating — the real-world current
At 55 °C it derates to 240 A, at 60 °C to 235 A, at 65 °C to 230 A, and at 70 °C to 225 A. The ETU320 electronic trip gives you adjustable pickup and time curves, so coordination with downstream 3VA breakers is straightforward.
That 138 mm width on a 3-pole frame means it occupies three adjacent 45 mm DIN-rail spaces — standard for a 250 A SENTRON. The ETU320 is self-powered from the line-side current; no control power needed for the trip unit.