This is a line-protection version — no voltage trip, no phase-failure detection, no ground-fault monitoring module built in. Communication function is present, so it can talk to a higher-level system via the SENTRON bus.
Panel fit and thermal derating
Thermal derating is published: full 100 A up to 50 °C ambient, then it steps down to 96.25 A at 55 °C, 92.5 A at 60 °C, 88.75 A at 65 °C, and 85 A at 70 °C. If your panel hits 55 °C near the top of the enclosure, you lose about 4 A per pole — plan the load accordingly.
The interrupting capacity curve drops from 187 kA at 240 V to 121 kA at 415/440 V, then to 79 kA at 500 V, and 4.25 kA at 690 V. For 480 V distribution, the 79 kA at 500 V gives you headroom for most industrial services. The ETU550 allows zone-selective interlocking if paired with a compatible upstream breaker, which can reduce arc-flash incident energy on the line side.