Question 74Electricity & Electronics - Assistant Engineer

The correct answer is D) no refurbishment or replacement was necessary through 2011. The plots show that the uncorrected insulation resistance readings remained well above the minimum acceptable level throughout the period from 2006 to 2011. The temperature-corrected readings also showed no significant decline over this time. Based on this data, there was no indication that the equipment required refurbishment or replacement during this period, as the insulation resistance levels remained satisfactory. The other answer choices (2006, 2008, 2010) are incorrect because the data does not suggest the equipment needed attention at those specific times.