Control unit for EasyPact NW drawout breakers
The Schneider Electric ENW21412 is a Trip System 2.0A microprocessor-based control unit for the EasyPact NW range of drawout circuit breakers. It provides LI protection — long-time overload and instantaneous short-circuit — with a trip unit rating adjustable from 800 to 4000 A, rated for 690 V AC at 50/60 Hz per IEC 60947-2.
Protection and coordination features
Long-time pickup (Ir) is adjustable across 9 settings from 0.4 to 1.0 x In, with a corresponding long-time delay adjustable from 0.5 to 24 seconds at 6 x Ir (accuracy 0 to -20%). Instantaneous pickup (Ii) is also adjustable across 9 settings, covering 1.5 to 10 x Ir with +/- 10% accuracy. Zone selective interlocking (ZSI) is built in, enabling coordinated tripping in a selective system — downstream faults clear instantly while upstream breakers wait for their delay, keeping the healthy part of the plant online.
Measurement, display, and diagnostics
The unit measures instantaneous current on all three phases and neutral (I1, I2, I3, In) across a 0.2 to 1.2 In range with +/- 1.5% accuracy, and logs maximum current. A digital display shows fault indications for overload, short-circuit, earth fault, and internal fault.
Pole configuration and neutral protection
The ENW21412 supports 3-pole and 4-pole breaker configurations with the neutral on the left. Protected poles can be set to 3D (three poles, no neutral protection), 3D + N/2 (neutral protected at half the phase pickup), or 4D (all four poles protected). This flexibility lets the same control unit serve solidly-grounded, impedance-grounded, or corner-grounded delta systems without a hardware change.