Littelfuse 460-400Hz Three-Phase Voltage MonitorLittelfuse 460 400Hz Voltage Monitor Product Description The Model 460 400Hz is designed to protect 3 phase, 400Hz motors from damaging power conditions. The 460s wide operating range combined with UL and CE compliance enables quick access to domestic and global markets. A unique microcontroller based voltage and phase sensing circuit constantly monitors the 3 phase voltages to detect harmful power line conditions. When a harmful condition is