It is a line-protection version — meaning it is set up for feeder or main breaker duty, not motor-circuit protection, so the trip curve and accessories are tuned for cable and busbar protection rather than motor starting inrush. The interrupting ratings tell you where this breaker can sit in a fault-current study: 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. Thermal derating is published per degree: full 400 A up to 50 °C, then 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C.
The 184 mm width for a 4-pole 400 A frame is standard for this class — check your enclosure gland-plate clearance and phase-barrier spacing before laying out the panel. That gives you status feedback for the SCADA or PLC — one set for breaker open/closed, one for trip indication, and one for electrical alarm. Communication function is built in — the ETU560 supports PROFIBUS or PROFINET via a communication module, letting you read current, power, energy, and trip data remotely. That is useful for a main breaker in a power-monitoring scheme, but confirm the specific module variant for your network protocol.