The 160 A rating holds from 40 °C through 50 °C ambient — no derating needed in a typical warm panel — then steps down to 154 A at 55 °C, 148 A at 60 °C, 142 A at 65 °C, and 136 A at 70 °C. That thermal curve means you size the breaker for the load at your enclosure's worst-case internal temperature, not the nameplate. Breaking capacity runs 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V. At typical 400 V distribution, the 121 kA SCCR gives substantial headroom above most utility fault levels — coordination studies will clear without cascading upstream.
Power loss is 19.7 W maximum at rated current — factor that into your enclosure thermal calculation, especially if the panel packs multiple breakers side by side. The ETU320 is a basic electronic trip unit; no communication function, no voltage trigger, no undervoltage release, no phase failure detection. It's a straight line-protection breaker, not a power-monitoring device.