Which of the following represents common uses for a megger/hipot tester?

• A. Generators for phase to phase
• B. Windings in the motor
• C. Identify any short circuits
• D. All of the above

Answer: (D)

Insulation resistance testing with a megger or hipot is about applying a high DC voltage to insulation and measuring how much leakage current flows. This tells you how well the insulation is holding up and whether there are creeping currents that could indicate deterioration or faults.

Testing motor windings is a primary use: you assess insulation between the winding and ground, and sometimes between windings themselves, to ensure the insulation is still sound and won't fail under voltage in service. This helps prevent surprising faults and electric shocks.

It’s also used to identify short circuits or leakage paths. If the insulation has degraded, leakage current increases and the measured resistance drops, signaling trouble before it becomes a safety or reliability issue.

In generators and similar equipment with multiple phases, you check insulation between phases as well as to ground, ensuring there are no unintended paths for current that could cause cross-talk, overheating, or faults.

All of these reflect common applications for megger/hipot testing, so the best answer is that all of the above are typical uses.