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

IEEE 45 guidelines state that insulation resistance plots remaining above minimum recommended threshold values require no intervention. Through 2011, measured values stayed within safe operational limits, making refurbishment or replacement unnecessary per marine electrical maintenance standards.