The ETU550 provides adjustable trip settings (L, S, I, G) for coordinating with downstream feeders and protecting cable or bus runs in distribution panels. Breaking capacity is 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3 kA at 690 V — so the part handles high available fault current on the low-voltage side of a 400 V transformer, but at 690 V the interrupting rating drops sharply; verify the fault level at your system voltage.
Front IP40 protects against tool entry in a closed panel. Communication function is onboard, enabling remote trip indication and parameter readback without opening the panel door.