* Transformers with natural ventilation
** Transformers with forced ventilation
| Average noise level | KVA* | KVA** |
|---|---|---|
| 48 | 0-50 | --- |
| 51 | 51-100 | --- |
| 55 | 101-300 | --- |
| 56 | 301-500 | --- |
| 57 | 700 | --- |
| 58 | 1000 | --- |
| 60 | 1500 | --- |
| 61 | 2000 | --- |
| 62 | 2500 | --- |
| 63 | 3000 | --- |
| 64 | 4000 | --- |
| 65 | 5000 | --- |
| 66 | 6000 | --- |
| 67 | 7500 | 6250 AND MINORS |
| 68 | 10000 | 7500 |
| 69 | --- | 9375 |
| 70 | --- | 10000 |