Why is it important to know the consumption of copper cables between the TC and the energy meter?
Because these cables can distort the measurement if they are not taken into account!
In other words, cables have:
- electrical resistance,
- therefore they cause energy loss (heating),
- which can distort the measurement, especially if the cable is long, because the meter will not have enough power to function properly.
It is therefore essential when sizing the electrical installation to take into account the distance of the cables between the energy meter and the current transformers.
Important
It is important to note that the current transformer must have sufficient VA to power the electronic device and compensate for power loss in the cable. As a reminder, the larger the cable cross-section, the less power loss there is.
Compatibility table
The table below shows the power consumption of cables as a function of distance.
| Cables | 1 metre | 2 metres | 3 metres | 4 metres | 5 metres |
|---|---|---|---|---|---|
| Section (mm2) | Loss in VA/metre | Loss in VA/metre | Loss in VA/metre | Loss in VA/metre | Loss in VA/metre |
| 2 x 1 | 0.92 | 1.84 | 2.76 | 3.68 | 4.6 |
| 2 x 1.5 | 0.61 | 1.22 | 1.83 | 2.44 | 3.05 |
| 2 x 2.5 | 0.37 | 0.74 | 1.11 | 1.48 | 1.85 |
| 2 x 4 | 0.23 | 0.46 | 0.69 | 0.92 | 1.15 |
| 2 x 6 | 0.17 | 0.34 | 0.51 | 0.68 | 0.85 |
| 2 x 10 | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 |
In summary
Knowing the consumption of copper cables between the CT and the meter is essential to ensure reliable measurement, avoid errors and not exceed the power delivered by the CT.