Depending on the type of cable (flexible or rigid) and its cross-section, it is possible to determine the diameter of the cable. The purpose of this table is to facilitate the dimensioning of the installation and to easily determine the appropriate current transformer.
This table shows the external diameter of a cable based on its cross-section.
For cupper cables (A)
| Flexible HO7 VK | Flexible HO7 RNF | Rigid RO2V | |
|---|---|---|---|
| Section (mm2) | Maximum external diameter (mm) | Maximum external diameter (mm) | Maximum external diameter (mm) |
| 1.5 | 3.4 | 5.9 | 5.4 |
| 2.5 | 4.1 | 6.6 | 5.8 |
| 4 | 4.8 | 7.5 | 6.3 |
| 6 | 5.3 | 8.3 | 6.8 |
| 10 | 6.8 | 10 | 8.1 |
| 16 | 8.7 | 11.1 | 9.1 |
| 25 | 10.2 | 12.9 | 10.8 |
| 35 | 11.7 | 14.5 | 11.9 |
| 50 | 13.9 | 16.8 | 13.3 |
| 70 | 16 | 19.1 | 14.5 |
| 95 | 18.2 | 21.3 | 16.4 |
| 120 | 20.2 | 23.4 | 18.2 |
| 150 | 22.5 | 25.7 | 19.9 |
| 185 | 24.9 | 28.1 | 22.2 |
| 240 | 28.4 | 31.2 | 25 |
| 300 | - | 33.8 | 27.5 |
For aluminium cables (A)
| Rigid AR2V | |
|---|---|
| Section (mm²) | Maximum external diameter (mm) |
| 1.5 | - |
| 2.5 | - |
| 4 | - |
| 6 | - |
| 10 | - |
| 16 | - |
| 25 | 10.8 |
| 35 | 11.9 |
| 50 | 13.3 |
| 70 | 14.5 |
| 95 | 16.4 |
| 120 | 18.2 |
| 150 | 19.9 |
| 185 | 22.2 |
| 240 | 25 |
| 300 | 27.5 |
The measurements in this table are indicative and may vary at any time from your cable supplier.
Example
The TAT022 with an opening of 22 mm will not be suitable for the HO7 RNF 1 x 120 mm² cable because its external diameter is 23.4 mm.
You will therefore need to select a current transformer with a larger opening, namely the TAC032, which has an opening diameter of 24 mm.