The Schneider Electric ENW21438 is a microprocessor-based control unit for the EasyPact NW range of air circuit breakers. It provides LSIG protection — long-time, short-time, instantaneous, and ground-fault — configurable across a trip unit rating of 800 to 4000 A.
Protection curve and adjustability
The Trip System 6.0A gives you nine adjustable settings each for long-time pickup (Ir, 0.4 to 1 x In), short-time pickup (Isd, 1.5 to 10 x Ir), and ground-fault pickup (Ig, 0.2 to 1 x In for 400 A < In ≤ 1000 A; 500 to 1200 x In for In ≥ 1250 A). Instantaneous pickup (Ii) is adjustable from 2 to 15 x In. Long-time delay (Tr) ranges from 0.5 to 24 s at 6 x Ir, accuracy 0 to -20%; short-time delay (Tsd) from 100 to 400 ms. Zone selective interlocking (ZSI) is included for tighter coordination between breakers in a cascade.
Physical integration and display
Fixed mounting, dimensions 200 mm high, 55 mm wide, 75 mm deep. The digital display shows fault type — overload, earth fault, short-circuit, internal fault — and includes an energy meter function. Thermal memory holds the last 20 minutes of thermal history before and after a trip, which prevents nuisance reclosing on a still-hot breaker. Neutral position is left; neutral protection can be set to without protection (3D), 0.5 x Ir (3D + N/2), or 1 x Ir (4D).