A significant deviation in winding resistance between phases indicates which issue?

• A. Healthy windings
• B. Balanced loads
• C. Possible winding fault or moisture ingress
• D. Rotor misalignment

Answer: (C)

In a generator, the winding resistance of each phase should be essentially the same. That symmetry ensures the three currents share load evenly and the machine runs without overheating or vibration of electrical service.

If one winding shows a significant deviation from the others, it signals a problem inside that winding rather than a normal condition. Possible issues include faults such as shorted turns or damaged turns, which shorten part of the conductor and change the resistance, or an open circuit where part of the winding is no longer conducting properly. Moisture ingress into the insulation can create leakage paths or worsen insulation integrity, leading to abnormal resistance readings and increasing the likelihood of winding faults.

The other options don’t fit this symptom: a healthy winding would not show a large difference; balanced loads affect current distribution rather than intrinsic winding resistance; rotor misalignment is a mechanical issue and wouldn’t cause a phase-to-phase resistance discrepancy.