A $1000 \mathrm{kVA}$, three-phase, $Y$-connected, 4160 $\mathrm{V}, 60 \mathrm{~Hz}$ synchronous gererator has an armature resistance and synchronous reactance of $0.14 \Omega$ and $2.5 \Omega$ per phase, respectively. If the power factor is 0.77 lagging, determine the full load generated voltage per phase.