Insulation Power Factor testing on an oil-filled transformer is not helpful in determining ___

• A. Movement of the windings (change in capacitance)
• B. Whether the oil test indicates moisture
• C. Condition of paper insulation (change in watts losses)
• D. Turns ratio values

Answer: (D)

A form of AC testing that applies voltage and measures the leakage/loss current of electrical insulation.
It is a type of insulation testing used to evaluate the integrity of electrical insulation.