Internal MV circuits
From Electrical Installation Guide
Internal MV circuits are dedicated to the supply of the secondary MV/LV substations dispersed in the installation. They are three typical principles commonly used for this purpose (Fig. D11):
- Single feeder
- Dual feeder
- Open ring
Fig. D11: Single feeder, Dual feeder, Open ring
Comparison of these three typical principles of internal distribution is given Fig D12.
| MV circuit configuration | |||
|---|---|---|---|
| Characteristic to consider | Single feeder | Open ring | Dual feeder |
| Site topology | Any | Single or several buildings | Single or several buildings |
| Power demand | Any | > 1250kVA | > 2500kVA |
| Disturbance sensitivity | Long interruption acceptable | Short interruption acceptable | Short interruption not acceptable |
Fig. D12: Comparison of the typical internal circuits
