MCCB for high-fault plant feeders
The ETU860 electronic trip unit gives you adjustable long-time (tr 0.5–25 s) and short-time (tsd 0.05–0.5 s) delay settings, so coordination with downstream breakers is tunable, not fixed. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, and 53 kA at 690 V — numbers that put this squarely in high-fault-current plant feeders or transformer secondaries where the available fault current is well above typical 25–65 kA MCCB ratings.
Full 1000 A holds through 55 °C ambient; at 60 °C it derates to 955 A, at 65 °C to 885 A, and at 70 °C to 815 A. That's a shallow curve — you lose 18.5 % by 70 °C, not the steeper drop some frames show — so a warm enclosure (say 50–55 °C) still delivers the nameplate current. Max power loss is 123 W, which factors into enclosure cooling calcs. Dimensions: 210 mm wide, 320 mm high, 120 mm deep. Front IP40.
Communication and monitoring
ETU860 release supports communication function and other measurement function. Ground fault monitoring uses summation current formation on L-conductor. Latching endurance is 10 000 cycles mechanical.