EV Charging Terminology

Single-phase charging uses a single-phase AC supply, commonly found in many UK domestic and small commercial installations. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.

Surge protection reduces the risk of damage from transient overvoltages caused by lightning, switching events or network disturbances. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.

Three-phase charging uses a three-phase AC supply and can support higher AC charging rates where the vehicle and charger are compatible. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.

TN-C-S earthing is an arrangement where neutral and protective functions are combined in part of the supply and separated within the installation. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.

TN-S earthing is an arrangement where the neutral and protective earth conductors remain separate from the supply source to the installation. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.

TT earthing is an arrangement where the installation uses its own earth electrode rather than relying on the distributor's protective conductor. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.

EV charging provided at offices, depots, staff car parks or commercial premises for employees, visitors or business vehicles. It is normally used to match charger features to the intended environment, utilisation pattern and user group.