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Dry-Type vs. Oil-Immersed Transformer Maintenance Guide
A proper maintenance regimen is essential to maximize the life, reliability, and safety of any transformer. However, the required maintenance differs significantly between dry-type and oil-immersed designs. Understanding these differences is key to planning your operational budgets and schedules.
Oil-Immersed Transformer Maintenance
Oil-immersed transformers require a more involved and scheduled maintenance approach to monitor the condition of the insulating oil and the internal components.
Regular Oil Sampling and Testing: This is the most critical task. Labs analyze oil for:
Dielectric Strength: Measures insulating ability.
Water Content: High moisture reduces insulation life.
Dissolved Gas Analysis (DGA): The most important test. Specific gases generated inside the transformer can indicate incipient faults like arcing or overheating long before they cause failure.
Inspections: Check for oil leaks, corrosion, and the condition of silica gel in breathers.
Component Maintenance: Maintenance of bushings, tap changers, and cooling fans.
Dry-Type Transformer Maintenance
Maintenance for dry-type transformers is simpler and focuses on keeping the unit clean and dry.
Regular Visual Inspections: Check for signs of overheating, corrosion, or damage.
Cleaning: Crucial for dry-types. Dust and contamination can reduce creepage distances and lead to tracking or flashover. Cleaning should be done with compressed air or vacuuming, following manufacturer guidelines.
Infrared Thermography: An excellent tool for identifying hot connections, bushing issues, or unbalanced phases under load.
Insulation Resistance Testing: Periodic Megger testing can help track the condition of the winding insulation over time.
Comparison at a Glance
Maintenance Aspect | Oil-Immersed Transformer | Dry-Type Transformer |
|---|---|---|
Core Task | Oil Analysis (DGA) | Cleaning & Visual Inspection |
Complexity | Higher (requires lab analysis) | Lower |
Cost | Higher (ongoing testing costs) | Lower |
Primary Risk | Internal faults, oil degradation | Contamination, moisture ingress |
Proactive Maintenance for Peace of Mind
Whether you choose oil-immersed or dry-type, a proactive maintenance plan is cheaper than the cost of an unexpected failure and downtime.
Qinghao Electric offers comprehensive transformer maintenance services and lifecycle support, from diagnostic testing to repairs.
