What this control unit does
The Schneider Electric LV847288WW is a MicroLogic 6.0 Xi electronic control unit for MasterPacT circuit breakers. It provides LSIG protection — long-time and short-time overcurrent, instantaneous short-circuit, and earth fault — with adjustable time delays and thresholds. The unit also functions as a power meter, measuring voltage, current, power, energy, harmonics, and frequency across the network. Measurement voltage spans 208...828 V AC phase-to-phase and 120...480 V AC phase-to-neutral. The trip unit is rated for currents from 400 A up to 6300 A, depending on the breaker frame (MTZ1/MTZ2/MTZ3). Accuracy is Class 0.5 for voltage and unbalance, Class 1 for active energy and power, Class 2 for THD(V), and Class 5 for THD(I). Current measurement accuracy is +/- 0.5% across the full range for all three frame sizes.
Protection and metering in one package
This unit combines protection relay and revenue-grade metering in a single control unit that mounts fixed inside the MasterPacT breaker. The LCD display (128 x 96 pixels) shows real-time values, event logs, alarm logs, and maintenance logs with time stamping. Thermal memory is included, so the unit tracks heat buildup across overload events. Zone selective interlocking (ZSI) is supported, allowing multiple breakers in a distribution system to coordinate trip timing and reduce arc-flash energy. The unit communicates via USB peer-to-peer at 115 kbauds for local configuration and data retrieval. Overvoltage category IV per IEC 61010-1 confirms it can be installed at the service entrance or main distribution panel. Indoor use only; not approved for wet locations.
The LV847288WW complies with EN/IEC 60255-1 (measuring relays), EN/IEC 60947-2 (circuit breakers), EN/IEC 60092-202 (marine electrical), EN/IEC 60947-1 (low-voltage switchgear), and EN/IEC 61010-1 (safety requirements for electrical equipment). EMC immunity covers electrostatic discharge, radiated fields, fast transients, surge 1.2/50 µs, and conducted RF per IEC 61000-4-2 through -6. Conducted and radiated emissions meet Class A of CISPR 22.
Pole configurations and neutral protection
The control unit supports 3-pole and 4-pole breaker configurations. Protected pole options include 3P 3d, 4P 3d, 4P 3d + N/2, 4P 4d, and 4P 3d + OSN. Neutral protection settings are selectable: 1 x Ir (4P 4d), 0.5 x Ir (4P 3d + N/2), 1.6 x Ir (4P 3d + OSN), or no protection (4P 3d).