Transformer failures are typically ignored because they communicate through weak indicators.
Ignoring these early signs might cause unanticipated outages, equipment damage, & costly repairs.
Here are 6 common indoor transformer faults and their potential interpretations:
6 Common Faults found in Indoor Transformers
- Insulation Breakdown
- Core Earthing Failure
- Overloading
- Overheating
- Partial Discharges (PD)
- Oil Leaks
1). Insulation Breakdown
Symptom: Flashovers, low insulation resistance (IR) values
Risk: Electrical faults & insulation collapse
Solution: Schedule regular insulation resistance & tan delta tests to detect early insulation degradation.
2). Core Earthing Failure
Symptom: Unexplained (or) unexpected differential relay trips
Risk: Induced voltages & potential internal arcing
Solution: Inspect & ensure core earthing continuity at routine shutdowns.
3). Overloading
Symptom: Overheating, frequent tripping at peak hours
Risk: Accelerated insulation aging & thermal stress
Solution: Monitor load in kVA, review loading patterns, & balance phases to prevent overload.
4). Overheating
Symptom: High temperature alarms, and rapid oil degradation
Risk: Insulation damage & reduced transformer life
Solution: Clean radiator fins, check fan operation, & test oil temperature relays for the proper function.
5). Partial Discharges (PD)
Symptom: Audible hissing sounds, corona marks on the insulation
Risk: Localized dielectric breakdown & eventual flashover
Solution: Use PD detection tools & visually inspect bushings & insulation systems.
6). Oil Leaks
Symptom: Visible oil stains, low oil level indicators
Risk: Loss of insulation & cooling capacity
Solution: Tighten fittings, replace damaged gaskets, & inspect conservator and breather systems.
Transformer failure is best prevented by early identification and maintenance.
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