The ETU350 LSI trip gives you separate adjustments for long-time (overload), short-time (short-circuit with intentional delay), and instantaneous (high fault) protection, so you can coordinate selectively with downstream breakers.
Deployment context
The 250 A frame and 55 kA rating suit it for main feeder or large motor branch protection in 415 V three-phase systems — common in pump stations, conveyor lines, and compressor skids. The shunt trip and auxiliary switches are wired back to the control circuit; verify the shunt trip coil voltage matches your control supply (208–277 V AC).