3 phase voltage controllers which monitor：- Undervoltage, adjustable from -2％ to -20％ of Under voltage,- Overvoltage, adjustable from 2％ to 20％ of Under Voltage,- Presence of the neutral （H3USN only）, Measurements are taken between Phases for the H3US - M3US and between Phases and Neutral for the H3USN, Faults are signalled via LED's, distinguishing the origin of the fault （one LED for the upper and lower threshold）
H3US and M3US relays control overvoltage between phases, and undervoltage between phases The H3USN relay controls overvoltage between phases, undervoltage between phases, and loss of neutral Multi-voltage Products True RMS measurement LED status indication
