The Schneider Electric LV839216 is a MicroLogic 5.0 X electronic control unit for MasterPacT air circuit breakers. It provides LSI protection — long-time, short-time, and instantaneous — plus integrated power and energy metering with a 128 x 96 pixel LCD display. The trip unit rating spans 400 A to 6300 A, so the same control unit fits across the MasterPacT frame range. The 4P 3d pole notation means the unit is wired for four poles but protects three — the fourth pole is a switched neutral without overload protection. This is the standard configuration for a 3-phase + neutral distribution board where the neutral is switched but not monitored for overcurrent. Other neutral protection settings are available (1 x Ir, 0.5 x Ir, 1.6 x Ir, or no protection) depending on the system grounding.
Protection and metering depth
The LSI protection functions cover overload (ANSI 49), instantaneous short-circuit (ANSI 50), and short-time short-circuit (ANSI 51). Long-time pickup is adjustable from 0.4 to 1 x In in 1 A steps, and the long-time delay is adjustable in 0.5 s increments. Zone selective interlocking (ZSI) is included, which allows multiple breakers in a cascade to communicate fault direction and speed up clearing while maintaining selectivity. Metering covers the full electrical network picture: phase and neutral currents, ground fault current, phase-to-phase and phase-to-neutral voltages, active/reactive/apparent power and energy, power factor, frequency, demand values, and total harmonic distortion for both current and voltage. Accuracy is ±0.5% for current and voltage, ±1% for active power and energy, and ±2% for reactive power and energy. The measurement voltage range is 208…828 V AC phase-to-phase, 120…480 V AC phase-to-neutral at 50/60 Hz.
Communication and diagnostics
The control unit communicates via Bluetooth 4.0 LE (30 kbit/s), NFC (ISO 15963), and USB (115 kbaud). This allows local connection with a smartphone or laptop for configuration, data retrieval, and firmware updates without opening the panel door. The unit logs alarms, events, maintenance data, min/max values, and trip context — useful for post-fault analysis and predictive maintenance planning.
The LV839216 is certified to EN/IEC 60947-1, EN/IEC 60947-2 (circuit-breaker standard), EN/IEC 60255-1 (measuring relays), and EN/IEC 60092-202 (marine electrical installations). Relative humidity tolerance is 95% at 55 °C.