... 50/60Hz 220V, 230V, 240V, 380V, 400V, 415V for overvoltage, undervoltage, phase failure, phase sequence, three phase asymmetry ... phase and two phase circuit. They are widely used for industrial control systems, capacitor of power compensation, switch boards, ... to occurrence of dew.4. Pollution grade: 35 Installation category: Ⅱ6 Housing protection class IP20 ModelOvervoltage monitoringUndervoltage ...