It is configured for line protection and carries the ETU350 electronic trip unit, which gives you adjustable long-time (Ir), short-time (Isd), and instantaneous (Ii) response values — Ir adjustable up to 1000 A, Ii up to 10 000 A, and short-time delay tsd from 0.04 s to 0.4 s. This is the breaker you spec for a main feeder or large distribution panel where you need selectivity headroom and thermal-magnetic replacement logic.
Breaking capacity and temperature derating
Breaking capacity is the headline number for a main breaker: 242 kA at 240 V, 187 kA at 415 V, and still 74 kA at 690 V. That SCCR handles most utility-fault scenarios without cascading upstream — you can coordinate downstream feeders with confidence. On the thermal side, the breaker carries its full 1000 A from 40 °C through 55 °C, then derates to 955 A at 60 °C, 885 A at 65 °C, and 815 A at 70 °C. That flat top to 55 °C means no derating in a normal 40 °C panel environment; only a hot enclosure or adjacent high-loss gear pushes you into the derate curve.
Dimensions: 320 mm height, 210 mm width, 120 mm depth. The 210 mm width (8.3 in) is the critical fit dimension for a panel layout — it occupies three standard 70 mm MCCB module slots on a DIN rail or mounting plate.
Trip unit and adjustability
ETU350 release is a basic electronic trip unit with LSI curves. Long-time response value tr adjustable from 0.5 to 17, short-time delay tsd from 0.04 to 0.4 s. No communication function; ground fault monitoring not included.