- You may use below numbers to correct the insulation resistance values to 20 °C.
- For example, assume you have an oil filled transformer and you get a reading of 1200 megaohms at a temperature of 35 °C. From table below you read accross at 35 °C to next column and obtaion the factor 2,80. Then your corrected resistance value is : 1200 megaohms x 2,80 = 3360 megaohms at 20°C.
|
Temperature |
Temperature Correction Factor for Oil Filled Transformers | |
|---|---|---|
| °C | °F | |
| 0 | 32 | 0,25 |
| 5 | 41 | 0,36 |
| 10 | 50 | 0,50 |
| 15 | 60 | 0,74 |
| 20 | 68 | 1,00 |
| 25 | 77 | 1,40 |
| 30 | 86 | 1,98 |
| 35 | 95 | 2,80 |
| 40 | 104 | 3,95 |
| 45 | 113 | 5,60 |
| 50 | 122 | 7,85 |
| 55 | 131 | 11,20 |
| 60 | 140 | 15,85 |
| 65 | 149 | 22,40 |
| 70 | 158 | 31,75 |
| 75 | 167 | 44,70 |