The Schneider Electric LV847287 is a MicroLogic 7.0 X electronic control unit for MasterPacT circuit breakers. It is the brain that provides equipment protection, monitoring, and control — not just a trip unit but a power meter and communication hub rolled into one. The 7.0 X designation means it carries LSIV protection (long-time, short-time, instantaneous, and earth-leakage) plus zone selective interlocking (ZSI) for faster fault clearing in coordinated distribution systems. This unit fits fixed-mounted MasterPacT breakers with 4P 3d or 4P 4d pole configurations. The trip unit rating covers a wide band — 400 A through 3200 A — so the same control unit model serves multiple breaker frame sizes. That matters for spares holding: one LV847287 on the shelf backs up a range of installed breakers, not just one amp rating. The LCD display (128 x 96 pixels) shows real-time metering: phase currents, neutral current, ground-fault current, line-to-line and line-to-neutral voltages, active/reactive/apparent power, power factor, energy, frequency, THD, and unbalance. Accuracy is Class 1 for active energy, Class 0.5 for voltage unbalance. This is not a basic trip unit — it replaces a separate power meter in the same panel footprint.
The LSIV protection suite covers the full curve: long-time overload (ANSI 49), short-time short-circuit (ANSI 51), instantaneous short-circuit (ANSI 50), and earth-leakage (ANSI 51G). The long-time delay is adjustable in 0.5 s steps. Zone selective interlocking (ZSI) is built in — when a downstream fault occurs, the upstream breaker holds off for a programmed delay while the downstream breaker clears instantly, keeping power on the rest of the bus. This is the difference between a nuisance plant-wide outage and a single feeder drop. Neutral protection is configurable: 1 x Ir for full 4P 4d, 0.5 x Ir for 4P 3d + N/2, 1.6 x Ir for 4P 3d + OSN, or no protection for 4P 3d. That flexibility lets the same control unit match different system grounding schemes without a hardware change.
Metering and communication
The LV847287 measures voltage phase-to-phase (208…828 V AC) and phase-to-neutral (120…480 V AC) at 50/60 Hz. Current accuracy is ±0.5 % across the measurement range for all three MasterPacT frame sizes (MTZ1, MTZ2, MTZ3). It logs events, min/max values, alarms, and maintenance data with time stamps. Thermal memory is included — important for motor feeders where repeated overloads accumulate heat. Communication ports include Bluetooth 4.0 LE (30 kbit/s), NFC (28.8 kbaud), and USB (115 kbaud). No separate communication module is needed for local access — pull up the data on a phone or laptop via Bluetooth for commissioning or troubleshooting. The unit also supports peer-to-peer NFC for quick parameter readout.
Installation environment and compliance
Rated for indoor use only, pollution degree 3, overvoltage category IV per IEC 61010-1. Operating altitude up to 5000 m with voltage derating to 560 V AC. Relative humidity tolerance is 95 % at 55 °C. Not approved for wet locations — keep it inside the switchgear enclosure. Standards compliance spans IEC 60947-1 (low-voltage switchgear), IEC 60947-2 (circuit-breakers), IEC 60092-202 (marine electrical installations), IEC 60255-1 (measuring relays), and IEC 61010-1 (safety requirements for electrical equipment). EMC immunity covers electrostatic discharge, electromagnetic fields, fast transients, surge (1.2/50 µs), and conducted RF. Emissions meet Class A of CISPR 22.