Suppose it is desired to determine the integrity of the insulation of a 4160 VAC motor. What type of insulation resistance tester (megger) would be suitable?

Correct Answer: Option D — 5000 V megger

Insulation testing of high-voltage machinery requires a megohmmeter rated above the operating voltage. Per IEEE 45 and manufacturer guidelines, a 4160 VAC motor winding necessitates a 5000 V insulation resistance tester to properly stress and evaluate dielectric integrity.