Breaking capacity and trip unit
The ETU320 is a basic electronic overcurrent release with adjustable long-time pickup (Ir) and long-time delay (tr). Ir is adjustable from 0.5 to 17 seconds, and the rated continuous current Iu is fixed at 25 A. The trip unit is line-protection only — no ground-fault or communication functions on this version. Breaking capacity drops as voltage rises: 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.8 kA at 690 V. At 690 V the figure is low enough that you need to check whether it still coordinates with downstream devices — that's a selectivity study point, not a worry for standard 400/415 V distribution.
Storage range is wider: -40 °C to 80 °C.