Comprehensive testing of transformer oil is essential for power equipment safety. The key tests can be grouped into Electrical, Chemical, Physical, and Contaminant categories.
The table below summarizes the most critical transformer oil tests, their purposes, and standard methods for your reference.
| Category | Test Parameter | Purpose & Significance | Common Test Standards |
|---|---|---|---|
| Electrical Properties | Breakdown Voltage | Measures insulating strength; low value indicates contamination by moisture/particles. | IEC 60156, ASTM D1816 |
| Dielectric Dissipation Factor (tanδ) | Assesses dielectric energy loss; high value signals oil aging/contamination. | IEC 60247, ASTM D924 | |
| Dissolved Gas Analysis (DGA) | Detects fault gases (e.g., H₂, CH₄, C₂H₂) to diagnose internal faults like arcing/overheating. | IEC 60567, ASTM D3612 | |
| Chemical Properties | Acid Number | Measures acidic content; high value indicates oil oxidation/aging. | IEC 62021, ASTM D974 |
| Interfacial Tension (IFT) | Detects polar contaminants/oxidation products; low value suggests advanced aging. | ASTM D971, IEC 62961 | |
| Oxidation Stability | Evaluates oil's resistance to aging under accelerated conditions. | ASTM D2112 (Rotating Bomb), IEC 61125 | |
| Physical Properties | Water Content | Measures moisture; high level severely reduces dielectric strength. | IEC 60814, GB/T 7600 |
| Color | Simple visual indicator of aging/contamination. | ASTM D1500 | |
| Viscosity (at 40°C) | Affects heat transfer/cooling efficiency. | ISO 3104 | |
| Flash Point | Indicates fire safety risk; low point suggests volatile contaminants. | ISO 2719 | |
| Pour Point | Determines low-temperature fluidity. | ISO 3016 | |
| Contaminants | Particle Count | Quantifies solid impurities that can com |