It carries a shunt trip (STL) release for remote opening and includes phase failure detection — a critical feature for motor protection applications where loss of a phase can single-phase a load and burn it out. The interrupting ratings are substantial: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V, so it handles high-fault-current scenarios typical in industrial main feeders or large sub-distribution boards. This is a motor protection version (product version field), meaning the trip curves and release are configured for motor starting inrush and overload profiles rather than straight feeder protection.
The breaker accepts plug-in or fixed connections depending on the accessory base selected; the shunt trip (STL) is integrated at the factory (design of the auxiliary release: shunt trip), so no field assembly of the trip coil is needed. The ETU350M is powered from the line side and requires no external control power for trip functions.
Temperature derating and power loss
Above that, derating applies: 96 A at 55 °C, 94 A at 60 °C, 92 A at 65 °C, and 90 A at 70 °C. Maximum power loss is 75 W at rated current — a figure to consider for enclosure thermal management, especially in sealed or high-ambient cabinets.