Interrupting capacity runs 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 5 kA at 690 V. That's a lot of fault-clearing headroom — it'll handle a hard bolted fault on a 400 V bus without the upstream transformer breaker having to clear it.
Where it goes in the panel
IP40 front keeps dust out of the trip-unit compartment. Comes with one auxiliary switch and one trip-alarm switch as standard — that's enough to signal the breaker's status and a fault trip back to the PLC without adding a separate contact block. No undervoltage release, no shunt trip, no ground-fault module on this variant; those are add-on accessories that clip into the same accessory slot.
Thermal limits and real-world current
Rated 100 A continuous up to 50 °C ambient. Above that it derates: 96.25 A at 55 °C, 92.5 A at 60 °C, 88.75 A at 65 °C, and 85 A at 70 °C. The ETU350's thermal memory also accounts for pre-load before a fault, so nuisance trips are less likely on a warm reclose. Maximum power dissipation is 10 W at rated load. That's low enough that you don't need forced ventilation for just this breaker, but if you're stacking several in a row, add up the watts and check the panel's thermal budget.