The ETU350 electronic trip unit handles the overcurrent response, adjustable for long-time, short-time, instantaneous, and ground-fault curves.
This MCCB's short-circuit rating drops as voltage rises: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. At 690 V the 40 kA figure still covers most industrial service-entrance faults, but if your plant runs a 690 V bus with available fault current above that, you need a higher-rated frame.
Above that, current must be derated: 612 A at 45 °C, 593 A at 50 °C, 575 A at 55 °C, 557 A at 60 °C, 538 A at 65 °C, and 520 A at 70 °C. If the panel sits in a hot environment — near a furnace, in a non-climate-controlled enclosure — the 70 °C derating to 520 A is the real continuous limit.
Trip unit and release configuration
The ETU350 overcurrent release provides electronic protection with adjustable settings. Maximum power loss is 162 W.
Dimensions are 110 mm deep, 138 mm wide, 248 mm tall. The 3-pole frame mounts into a standard MCCB cutout in a distribution panel or switchboard. Verify the bus-bar spacing and mounting hole pattern against your existing panel layout — the 138 mm width is typical for a 630 A frame, but a retrofit into a smaller cutout may require a sub-panel adapter.