IEC 60599:2022 Ratio Analysis
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Three-ratio method for transformer fault classification in mineral oil
Gas Concentrations (ppm)
Load example:
Hydrogen
Recommended range: 0 to 100 ppmMethane
Recommended range: 0 to 120 ppmAcetylene
Recommended range: 0 to 1 ppmEthylene
Recommended range: 0 to 50 ppmEthane
Recommended range: 0 to 65 ppmLoad sample data:
Zone Visualization
PD
D1
D2
T1
T2
T3
Enter gas concentrations to see analysis results
About IEC 60599:2022
The IEC 60599 ratio method uses three gas ratios to classify transformer faults:
- R1 = C₂H₂/C₂H₄ (Electrical vs thermal)
- R2 = CH₄/H₂ (Fault temperature)
- R3 = C₂H₄/C₂H₆ (Thermal refinement)
NS = Not Significant (ratio cannot be calculated due to low denominator gas)
About the IEC 60599:2022 Ratio Method
The IEC 60599:2022 standard provides guidance on the interpretation of dissolved and free gases in mineral oil-filled electrical equipment. The three-ratio method is one of the most widely used techniques for transformer fault diagnosis worldwide.
The Three Ratios
- R1 = C₂H₂/C₂H₄(Acetylene/Ethylene) - Distinguishes electrical faults from thermal faults. High values indicate arcing.
- R2 = CH₄/H₂(Methane/Hydrogen) - Indicates the relative temperature of the fault. Low values suggest partial discharges.
- R3 = C₂H₄/C₂H₆(Ethylene/Ethane) - Refines thermal fault temperature classification. High values indicate higher temperatures.
Fault Types
| Code | Fault Type | Temperature Range | Severity |
|---|---|---|---|
| PD | Partial Discharges | < 150°C (cold plasma) | Medium |
| D1 | Discharges of Low Energy | Variable (arc) | High |
| D2 | Discharges of High Energy | > 3000°C (arc core) | Critical |
| T1 | Thermal Fault | < 300°C | Medium |
| T2 | Thermal Fault | 300-700°C | High |
| T3 | Thermal Fault | > 700°C | Critical |
Important Notes
- •NS (Not Significant) - When a gas concentration is too low, the ratio cannot be reliably calculated.
- •DT (Diagnosis Tentative) - When ratios don't match any defined zone, multiple concurrent faults may be present.
- •This tool should be used in conjunction with other diagnostic methods such as the Duval Triangle and Pentagon.
References
- •IEC 60599:2022 - Mineral oil-filled electrical equipment in service
- •IEEE Std C57.104-2019 - Guide for the Interpretation of Gases Generated in Mineral Oil-Immersed Transformers