At 415 V and 440 V the rating holds at 187 kA, dropping to 121 kA at 500 V and 40 kA at 690 V, so match the system voltage to the available fault current when specifying. The ETU320 is a basic electronic trip unit — no communication, no voltage trigger, no phase-failure detection, no ground-fault monitoring. It's sized for straightforward line protection where you need adjustable overload and short-circuit curves without the complexity of a full metering trip. The 2 auxiliary switches (HQ version) provide status feedback to the PLC or SCADA without an add-on module.
Temperature derating — don't lose capacity at the panel door
Above that, the continuous current must be derated: 384 A at 55 °C, 376 A at 60 °C, 368 A at 65 °C, and 360 A at 70 °C.
Mounting and integration — panel footprint
Dimensions are 138 mm wide, 248 mm high, 110 mm deep. The 3-pole frame mounts on a standard backplate or DIN-rail adapter (not included). If you need remote tripping, plan for an external shunt or UVR module.