At 415 V and 440 V the interrupting rating holds at 121 kA; at 500 V it drops to 75.6 kA, and at 690 V to 17 kA. The 400 A rating holds from 40 °C through 50 °C; above that it derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C.
The breaker measures 138 mm wide by 248 mm tall by 110 mm deep. The front face carries an IP40 protection rating — suitable for enclosed panel installation where no water ingress is expected.
The ETU350 is an electronic trip unit with adjustable long-time, short-time, instantaneous, and ground-fault protection bands — standard for selective coordination in distribution panels. Maximum power loss is 96 W at rated current, which matters for thermal management inside a sealed enclosure. The breaker has a trip indicator (mechanical flag) for visual confirmation of a trip event. It does not include undervoltage release, communication functions, phase failure detection, or ground-fault monitoring — this is a straightforward line-protection breaker, not a multifunction power monitor.