The phase voltage is the voltage between the Line and Neutral wire. The line voltage is the voltage difference of any two Line wires. For single-phase 3-wire, the Neutral wires are connected together and the phase difference is in 180 degrees, so line voltage = 2 phase voltage. For 3-phase 4-wire (Wye; Y; star), all Neutral wires are connected together and the phase difference are all 120 degrees, so line voltage = 1.732 phase voltage. For 3-phase 3-wire (delta), the Neutral wire is connected to the next phase Line wire, so line voltage = phase voltage. The initial setting voltage of our power supply is phase voltage, kindly pay attention to the conversion with the line voltage.