The interrupting capacity at 240 V is 242 kA, at 415 V it is 187 kA, and at 690 V it is 74 kA — figures that govern the available fault current the breaker can safely clear without upstream coordination failure. The ETU350 electronic trip unit provides adjustable long-time (tr) from 0.5 to 17 seconds and short-time delay (tsd) from 0.04 to 0.4 seconds, plus an instantaneous pickup (li) adjustable up to 10 000 A. That means the breaker can be tuned for selectivity with downstream devices, a key requirement for a main or feeder breaker in a distribution panel. Thermal derating is flat at 1 000 A from 40 °C through 55 °C, then drops to 955 A at 60 °C, 885 A at 65 °C, and 815 A at 70 °C.
The breaker measures 210 mm wide, 320 mm high, and 120 mm deep. The width of 210 mm (8.3 in) means it occupies three pole spaces in a typical panelboard or MCC bucket. No communication function is built in; the ETU350 is a standalone electronic trip unit without Modbus or PROFIBUS — coordination settings are adjusted locally via the trip unit dials.