JVRD series multi-function phase sequence voltage protection (also known as three-phase power supply monitor, phase sequence protection, over voltage protection, etc. ) mainly for the exchange of 50/60Hz, rated voltage 460V below, industrial three-phase 220V, 380V, 440V, 460V and so the voltage levels of a variety of fault detection, on the three-phase input power supply voltage is too high, low voltage, phase, reverse phase (phase sequence), to voltage unbalance relay protection, products are widely used in air compressor, electric motors, power distribution boxes, pumps, fuel pumps, central air conditioning units, electrical control boxes, distribution cabinets, cranes, etc., such as central air-conditioning compressor protection, monitoring of various power lifts, water pump, oil pump anti-phase, reverse phase protection, maintenance of industrial equipment operating in the normal operating voltage equipment indispensable protection products.