S320A High Voltage Phase Tester (a.k.a Wireless PSI Kilovoltmeter) is a wireless, battery-operated instrument designed to detect the rotary field of three-phase systems and determine phase sequence. This instrument includes a wireless receiver, XY transmitter, and a retractable insulated rod. The receiver uses a 3.5-inch true color LCD screen, which can display the phase sequence results, frequency, and a vector diagram all at the same time. The distance between two cables being measured can be up to 160m on open ground. It can be used on cables with voltage ranges from 10V to 550kV. Not only can the results be received wirelessly, making it convenient to detect cables’ sequences that are far apart, it can also be used using the non-contact method. Making it a much safer option for operators dealing with high voltage cables.