It uses the ETU350M electronic overcurrent release, which provides adjustable protection curves for motor starting inrush and overload profiles — the kind of coordination you need when a pump or compressor hits locked-rotor current without nuisance tripping the feeder. Breaking capacity runs from 187 kA at 240 V down to 17 kA at 690 V, with 121 kA at both 415 V and 440 V.
Integration & Panel Fit
Phase failure detection is built into the ETU350M trip unit, so a lost phase on a motor load triggers a trip rather than letting the motor single-phase and overheat. Maximum power dissipation is 101.5 W at rated load. In a sealed enclosure, factor that into the thermal budget — it is not a high-loss breaker for this frame, but at 500 A continuous the heat adds up if you pack multiple breakers in a small panel.
Derating & Ambient Temperature
Above that, it derates linearly: 495 A at 55 °C, 490 A at 60 °C, 485 A at 65 °C, and 480 A at 70 °C.