Lineman's Test C Practice

When a voltage surge couples between a phase conductor and the neutral, energy is shared between the two paths through their mutual impedance and stray capacitances. The neutral is tied to ground and has a return path that makes it more susceptible to rising in potential during the transient. As the neutral voltage climbs, the reference point for the circuit shifts upward, which reduces the voltage difference between the phase and the neutral. In other words, the phase conductor’s voltage tends to decrease while the neutral’s voltage increases during the surge, before the system returns to normal once the surge subsides.