LV Electrical Installations. Operative Rules to Implement Connections

On French electrical networks, the concept of connection only exists in low voltage (LV). The connection is the terminal part of the network intended for individual or collective supply to users, between the network (LV line or HV/LV substation outlet) and the customer's delivery point (PdL), where the meter and the cut-off device necessary to protect the installations inside the customer's premises are generally located. Enedis, France's main distribution system operator (DSO), which operates across 95% of mainland France and supplies 35 million customers, manages a total of 35 million connections, representing a significant percentage of its fixed assets. The power connected by these connections varies from 3 kVA to 240 kVA. They supply installations ranging from advertising billboards to small industrial facilities (yellow tariff), as well as individual residences, apartment buildings, commercial buildings, electric vehicle charging stations, etc. In recent years, the minimum annual number of housing units started has been around 350,000. As all these homes need to be connected to the electricity grid, it is easy to understand why standardization of the design, choice of materials used, studies, and implementation of connections was necessary at a very early stage:

• given the challenges:

  • personal safety and property preservation (emergency power cuts),

  • quality of service in public electricity distribution (limitation of voltage drops, control of overloads and overcurrents, and wave quality),

  • combating the fraudulent use of electrical energy;

• given the number of parties involved (project owner, project manager, design offices, distribution network operator, and gas, water, heating, and telecommunications network operators).

Low-voltage connection installations are governed by standard NF C 14-100, regardless of the network operator. This standard was reissued in 2021 to take into account changing user needs and technological developments. The rules for electric vehicle charging infrastructure (IRVE) are included in this edition.

It also takes into account the installation of public distribution points integrated into buildings and specifies the grounding scheme in such cases.

The NF C 14-100 standard specifies the conditions for carrying out connection installations, the basic principles being those defined in the fundamental NF C 15-100 standard, which concerns indoor installations in the user's premises.

The aim of this article is to shed light on these developments.