The ENW21418 is a microprocessor-based control unit for the Schneider Electric EasyPact NW range of air circuit breakers, carrying the Trip System 6.0A designation. It is the brains of the breaker — the part that measures current, decides when to trip, and communicates what happened. Rated for 800 to 4000 A at 690 V AC (50/60 Hz, per IEC 60947-2), it handles the full industrial power distribution band from a large feeder to a main incomer. Protection profile is LSIG: long-time overload (L), short-time short-circuit (S), instantaneous short-circuit (I), and ground fault (G). That covers the four protection curves a plant engineer needs for selective coordination — you can set the long-time pickup from 0.4 to 1 x In across nine steps, short-time pickup from 1.5 to 10 x Ir, instantaneous from 2 to 15 x In, and ground-fault pickup from 0.2 to 1 x In (for 400 A < In ≤ 1000 A) or 500 to 1200 x In (for In ≥ 1250 A). Each has its own adjustable time delay, so you can dial in the trip coordination study without swapping hardware. The unit also includes zone selective interlocking (ZSI), which lets multiple breakers in a distribution chain talk to each other over a control wire. When a fault occurs downstream, the breaker closest to the fault trips instantly; upstream breakers hold off for their set delay. That keeps a feeder fault from blacking out the whole switchboard.
Integration notes — drawout, dimensions, and panel fit
The control unit mounts in a drawout cradle — it slides out of the breaker housing without disturbing the power connections. That is the standard arrangement for EasyPact NW frames: the breaker chassis stays wired, and the trip unit comes out for testing, replacement, or setting changes. Dimensions are 75 mm deep, 55 mm wide, 200 mm tall — compact enough that the unit does not steal extra space inside the switchgear cubicle. The digital display shows fault type (overload, short-circuit, earth fault, internal fault) and energy metering data, so a field tech can read the last trip cause without connecting a laptop.