Littelfuse 460-575, 3-Phase Volt Mon/ 475-600V/ Ad

The 460 series is a three-phase voltage monitor that protects 190–480 V ac or 475–600 V ac, 50/60 Hz motors regardless of their size. This voltage monitor provides a user-selectable nominal voltage setpoint and will automatically sense line voltage. A unique microcontroller-based voltage and phase-sensing circuit constantly monitors the three-phase voltage to detect harmful power line conditions such as low, high, and unbalanced voltage, loss of any phase, and phase reversal. When a harmful condition is detected, the MotorSaver® output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level for a specified amount of time (restart delay). The trip and restart delays prevent nuisance tripping due to rapidly fluctuating power line conditions. All 460 models feature an adjustable 1–30 second trip delay, 1–500 second restart delay, 2–8 % voltage unbalance trip point, and one form C contact except where noted on the datasheet.