What this control unit does
The Schneider Electric ENW21439 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 through the Trip System 6.0E. The trip unit rating spans 800 to 4000 A, making it suitable for large industrial feeders and main incomers on 690 V AC networks at 50/60 Hz, conforming to IEC 60947-2.
Protection curves and adjustability
Each protection function is independently adjustable. Long-time pickup (Ir) has 9 settings from 0.4 to 1 x In, with a corresponding time delay (Tr) adjustable in 9 steps from 0.5 to 24 s at 6 x Ir. Short-time pickup (Isd) adjusts in 9 steps from 1.5 to 10 x Ir, with delay (Tsd) in 5 steps from 100 to 400 ms. Instantaneous pickup (Ii) has 9 settings from 2 to 15 x In, and can be switched off. Ground-fault pickup (Ig) adjusts in 9 steps: 0.2 to 1 x In for ratings up to 1000 A, and 500 to 1200 x In for 1250 A and above. Zone selective interlocking (ZSI) is included for coordinated tripping in a distribution hierarchy.
Thermal memory and fault indication
Fault indication covers overload, short-circuit, earth fault, and internal fault, shown on the digital display. The neutral protection setting is configurable: no protection (3D), 0.5 x Ir (3D + N/2), or 1 x Ir (4D). Protected poles can be set to 4D, 3D + N/2, or 3D.