The ENW24158 is a Schneider Electric EasyPact NW 4-pole air circuit breaker rated 1000 A at 40 °C, built for distribution duty in industrial switchboards. That 1 kA gap between Icu and Ics is tight — a sign the design is optimized for the duty cycle, not overbuilt. If your switchgear runs hotter than 40 °C, you derate per the manufacturer's curve — the operating range tops out at 60 °C. The 4-pole configuration with neutral left (3D + N/2 or 4D protection options) covers both 3-wire and 4-wire distribution, so you can protect the neutral at half or full rating depending on your system grounding.
Fixed-mount on a base plate, rear-connected. The 537 mm width by 352 mm height by 297 mm depth footprint is substantial — plan for a dedicated compartment in the switchboard, not a DIN-rail clip-in. Connection pitch is 115 mm without spreader, so busbar drilling and cable lug centers need to match that spacing. Vertical or horizontal connection orientation is accepted, which helps when routing busbars around existing gear. IP40 enclosure protection keeps tools and fingers out but does not stop water ingress — install in a dry indoor cabinet. The push-button control on the front gives local open/close without opening the door, which speeds fault isolation during commissioning.
Electrical durability at 440 V AC is 6,000 cycles under Category B duty (the utilization category for distribution breakers with no intentional overload before fault clearing). The 25 ms maximum breaking time and 70 ms closing response are fast enough for selective coordination with downstream devices, provided the upstream breaker's time-current curve is set accordingly. The contact position indicator on the front gives positive visual confirmation of open/closed state — no guessing from handle angle alone.