What you're looking at
The ETU350 electronic trip unit gives you adjustable long-time (0.5–17 s), short-time (0.04–0.4 s), and instantaneous (up to 8000 A) response. Interrupting capacity: 187 kA at 240 V, 121 kA at 415 V, 53 kA at 690 V. That's serious fault-current headroom for a main or large feeder in an industrial panel.
The 800 A rating holds across 40–60 °C ambient — no derating curve to calculate for typical panel environments. Above 60 °C it drops to 767 A at 65 °C and 703 A at 70 °C. The 187 kA at 240 V is the headline SCCR; at 415 V it still clears 121 kA, and at 690 V it handles 53 kA. That covers most industrial supply transformers and generator paralleling gear. The ETU350 release lets you shape the trip curve to coordinate with downstream breakers — set the short-time delay to ride through motor inrush without nuisance trips.
Panel fit & environment
Dimensions: 210 mm wide, 320 mm high, 120 mm deep — fits standard switchboard mounting. Front IP40 protects against tools and small objects; the interior is open-frame. Maximum power loss 135 W at rated current — plan ventilation accordingly for enclosed cubicles.