1.Suitable for three-phase four-wire, three-phase three-wire, two-phase three-wire, single-phase two-wire, power of 50Hz, 60Hz, 400Hz systems. 2.Accurately measure three-phase voltage, phase sequence, with over-voltage, under-voltage, phase loss, reverse phase sequence protection. 3.Aadopt adjustable potentiometer, used to set the threshold and delay value, and it has 2 relay outputs. 4.It has a test button to test overvoltage, undervoltage relays and their indicator lights. 5.Wide DC 8-35V power supply range, which can adapt to different starting battery voltage environments. 6.The relay adopts 35mm guide rail installation mode, modular structure designed , pluggable terminal block, compact structure and convenient installation. 7.The HVD300 AC voltage detection relay makes accurate judgments on the abnormal phenomena of AC voltage overvoltage, undervoltage, phase loss, and reverse phase sequence, and corresponding passive relay output, widely used in marine and land vehicles. Condition: 100% Brand New_x000D_ Item Type: AC Voltage Detection Relay _x000D_ Material: Plastic_x000D_ Color: As picture shown_x000D_ Working Voltage: DC8.0V - 35.0v Continuous Power Supply_x000D_ Total Power Consumption: