The electronic trip unit is an ETU350, a programmable LSIG (long-time, short-time, instantaneous, ground-fault) platform.
Interrupting capacity across voltage levels
The interrupting ratings span the common industrial voltages: 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.
Thermal derating — real-world continuous current
Above that, derate linearly: 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 ambient hits 50 °C, the breaker is good for 593 A continuous — a 6% reduction that must be factored into the load schedule.
Environmental and endurance limits
Mechanical endurance is 15,000 operations, typical for a fixed-mount MCCB in main distribution.