HTA Electric Installation. Regulation, Structure and Protections

High-voltage electrical installations include all those with voltages in excess of 1,000 V AC and 1,500 V DC. RTE (Réseau de Transport d'Électricité) uses voltages of 225 and 400 kV for long-distance power transmission, as well as intermediate voltages of 63 and 90 kV.

In this article, we'll be taking a closer look at 20 kV installations, the voltage used in France for the public distribution network for currents of less than 630 A.

The 3 and 5.5 kV voltages are dedicated to street lighting. The 5.5 and 6.6 kV voltages are used to power motors. The 11 kV voltage is used for distribution, particularly in the maritime sector. Other HV voltages are also used for public distribution: 10 kV, 13.2 kV, 15 kV, 30 kV. These are in the process of disappearing in France, but are still common in other countries.

Large industrial consumers can be supplied directly from the transmission grid at voltages of up to 225 kV.

HV electrical installations are covered in two articles:

• regulations, structure and protection [D 5 025] ;

• implementation and operation [D 5 026] .