Earth Rod explanation

What is an EV earth rod/electrode and do I need one?

An earth rod (or electrode) is a typically a conductive rod of steel or copper driven into the ground and connected to an EV chargepoint. This connection helps to protect the user from potentially lethal electrocution should the electricity distribution system supplying the property develop a fault. This is commonly known as “loss of the Protective Earth and Neutral (PEN) conductor”.

However, driving earth rods is time-consuming, expensive, and can be dangerous if you accidentally hit water mains or sewerage pipes laying below. Equally, installing near to underground pipes, or other metallic objects above ground (outside taps, lighting, metal cladding) that are connected to the house earthing system (known as a PME, or Protective Multiple Earth system) could actually make the installation more dangerous.

In 2020, the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI) introduced Amendment 1 to the 18th Edition IET Wiring Regulations to regulate standards for installing EV chargers without earth rods if one of the exceptions mentioned in the regulations is met.

New generation EV charging units, including Sync Energy, have been developed to allow installation without the need for an earth rod, whilst fully complying with the 18th Edition regulations.

But how does this system work?

Sync Energy chargers feature an on-board safety monitoring device to detect low or high voltage supplies and potential earth-neutral faults (this is in accordance with British wiring regulations for single phase supplies). If a fault condition is encountered the EV charge cycle is ended or prevented and the charger indicator goes red to show a fault. The charger isolates the power to the vehicle which effectively poses no risk to touch. This feature removes the requirement for an earth electrode where it may be ineffective or introduce further risk.