Do you need to install an earth rod for an EV charge point?

Question:

Do you need to install an earth rod for an EV charge point?

Answer:

Dan Jackson FIET,

722.411.4.1 states that A PME earthing facility shall not be used as the means of earthing for the protective conductor contact of a charging point located outdoors or that might reasonably be expected to be used to charge a vehicle located outdoors unless one of three conditions.

The three conditions are typically difficult to achieve. Two of which require calculations which can be found in ANNEX A722.

If the EV charge point is located outside or serves an electric vehicle that is located outside and the means of earthing is PME, then it is likely the EV charge point requires a separate earthing system to the PME earth such as an earth electrode in the many properties. Please note that TN-S earthing systems are treated the same as PME earthing systems.

While this is fine in some cases, it can present some issues in installations where the EV charge point is located within close proximity to the metallic building structure or exposed or extraneous conductive parts such as light fittings or outside taps. The building will likely be connected to PME, and the EV charge point will likely be separated from it. This leads to a potential issue, where the Electric Vehicle and charge point can be at a different potential to the building, increasing the chance of electric shock under fault conditions.