Inspection Of Dry-Type Transformers

1. Check for abnormal noise or vibration.
2. Check for discoloration caused by localized overheating, corrosion from harmful gases, or phenomena such as tracking marks and carbonization on insulation surfaces.
3. Verify the normal operation of the transformer's forced-air cooling system.
4. Ensure there is no overheating at high- and low-voltage connections, and no signs of leakage or tracking at cable terminations.
5. Monitor the winding temperature rise to ensure it does not exceed the limits specified for the insulation class used in the transformer.
6. Check support insulators for cracks or discharge marks.
7. Inspect winding clamping components for looseness.
8. Ensure indoor ventilation and core cooling ducts are free from dust and debris, and check the core for signs of rust or corrosion.