In a star (Y) connected three-phase system, the line voltage is the voltage measured between any two line conductors, while the phase voltage is measured between a line conductor and the neutral point. For a balanced system, the line voltage is $\sqrt{3}$ times the phase voltage, expressed as $V_L=\sqrt{3}V_{ph}$. The line voltage also leads its corresponding phase voltage by $30^\circ$ for the standard phase sequence. Thus, if the phase voltage is 230 V, the line voltage is approximately $230\times\sqrt{3}=398$ V, commonly represented as about 400 V in a three-phase supply.