What is an Earth Rod?
An earth rod (also called an earth electrode) is a conductive rod — usually copper-bonded steel or solid copper — driven vertically into the ground and bonded to an electric vehicle (EV) chargepoint. Its purpose is to provide a reliable path to earth, protecting users from potentially lethal electric shock if the supply system develops a fault.
The Specific Risk
The specific risk is known as loss of the Protective Earth and Neutral (PEN) conductor in a TN-C-S (PME) system. If this occurs, the neutral and earth can rise to mains voltage, meaning exposed conductive parts — including your car body — could become live. Without protection, touching the vehicle in this state could be fatal.
Problems with Installing Earth Rods
While earth rods are a tried-and-tested method, they come with practical and safety issues:
Installation Risk
Driving a rod into the ground can damage buried services such as water, gas, or sewer pipes.
Time and Cost
Correct installation requires proper depth (often 1.2–2 m) and testing, which can add significant labour costs.
Safety Paradox
If installed too close to buried metallic pipework, outdoor taps, metal fencing, or building cladding that is bonded to the PME system, a rod can unintentionally create dangerous touch voltages rather than eliminate them.
Soil Conditions
In rocky ground or dry soil with high resistivity, rods may be ineffective at providing the required low resistance to earth.
Regulatory Changes
To address these issues, the 18th Edition Wiring Regulations (BS 7671) were updated.
Amendment 1 (2020)
Introduced specific provisions for EV charging installations without earth rods where alternative protective measures are used. This means an earth electrode is no longer mandatory if the installation meets the conditions set out in the regulations.
Amendment 2 (2022)
Built further on this, requiring all EV chargepoints to have built-in protective devices against PEN conductor failure, unless a dedicated earth electrode is provided. In short: the regulations recognise that earth rods are not always the safest or most practical solution, provided certified protective technology is in place.
Modern Alternatives to Earth Rods
Newer EV charging units integrate PEN fault protection technology to eliminate the need for a ground rod in most domestic installations.
Examples of Protected Chargers
Examples include chargepoints from Sync EV, Myenergi Zappi, Ohme, and Easee.
How It Works
These devices continuously monitor the supply for abnormal conditions:
- Voltage imbalance between line and neutral
- Rise of earth potential relative to neutral
- Over/undervoltage events
If a fault is detected, the unit automatically disconnects the vehicle from the supply. Charging stops instantly, the vehicle body is isolated from live potential, and a fault indicator (often red) alerts the user.
Do You Need an Earth Rod Today?
If your charger has certified PEN fault protection (18th Edition Amendment 2 compliant) → No earth rod required.
If you have an older charger without this feature → An earth rod, or another form of compliant protection, will usually be required.
If in doubt → Your installer must confirm compliance with BS 7671:2018+A2:2022.
Bottom Line
Earth rods were once considered the default safeguard for EV charging, but modern regulation and charger technology have moved beyond them. Today, a properly certified charger with integrated PEN fault protection offers a safer, faster, and more cost-effective installation than physically driving an electrode into the ground — and in many cases, the rod may actually introduce new hazards.