The Schneider Electric LV839212 is a MicroLogic 2.0 X control unit for the MasterPacT range of air circuit breakers.
The trip unit rating is configurable: 400 A, 630 A, 800 A, 1000 A, 1250 A, 1600 A, 2000 A, 2500 A, 3200 A, 4000 A, 5000 A, and 6300 A. The long-time pickup (Ir) is adjustable from 0.4 to 1 x In in 1 A steps. The instantaneous pickup (Ii) is adjustable, and the long-time delay (tr) has three settable curves: 12.5–600 s at 1.5 x Ir, 0.5–24 s at 6 x Ir, and 0.7–16.6 s at 7.2 x Ir. This gives you the selectivity headroom to coordinate downstream breakers without nuisance tripping on motor inrush. Metering accuracy is Class 0.5 for voltage and current, Class 1 for active power and energy, and Class 2 for reactive power and THD. That means the built-in power meter is accurate enough for submetering and energy allocation without a separate revenue-grade meter.
Metering and Diagnostics — What the LCD Tells You
The 128 x 96 pixel LCD display shows all metered values locally: phase and neutral currents, line-to-line and line-to-neutral voltages, active/reactive/apparent power, power factor, frequency, THD, and unbalance. The unit logs min/max values, alarms, events, and maintenance logs with time stamps. The diagnostics suite includes circuit breaker health state, contact wear, trip cause indication, protection test results, and selectivity test results. Thermal memory is standard, so the trip curve remembers the thermal history of the protected conductor after a momentary overload.
Communication and Connectivity
The control unit communicates via Bluetooth 4.0 LE (30 kbit/s), NFC (28.8 kbaud), and USB (115 kbaud). This allows local configuration and data download using a smartphone or laptop without opening the panel door. Measurement voltage input is 208–828 V AC phase-to-phase and 120–480 V AC phase-to-neutral, 50/60 Hz.
Rated for operation from -25 °C to +70 °C (start-up down to -35 °C), with 95% relative humidity at 55 °C per IEC 60068-2-30. EMC tested per IEC 61000-4-2/3/4/5/6 and CISPR 22 Class A.