As shown in the illustrated plots of uncorrected and temperature corrected insulation resistance readings for a particular piece of equipment, at what point in time should the equipment have been refurbished or replaced? Illustration EL-0120

Correct Answer: Option D — no refurbishment or replacement was necessary through 2011

Insulation resistance trends plotted over time remain well above IEEE 45 minimum acceptable thresholds through 2011. Without moisture-induced degradation or sustained drops below the critical polarization index threshold, capital replacement or refurbishment is unnecessary.