If you have ever had a charger quote that included "earth rod" as a line item, or heard two installers give you two different answers about whether you need one, this guide is for you. Earthing is the single most misunderstood part of a home charger installation — and it has a direct impact on how much the install costs and how long it takes.
Here is what a PEN fault is, why it matters for EVs specifically, what the wiring regulations require, and which chargers we stock that handle it internally. For the wider installation process, see our EV charger installation guide.
PME supplies, in plain English
The cable that brings electricity into your home has to provide a path back to earth for safety. In older properties, that was often done with a separate earth conductor in the supply cable. In most modern UK homes, the network operator instead combines the neutral and the protective earth into a single conductor in the street. This is called PME (Protective Multiple Earthing), and your home's arrangement is described as TN-C-S.
The combined conductor is the PEN conductor — Protective Earth and Neutral. It works well, it is cheap to install, and it is extremely common. Under normal conditions, it is completely safe.
What is a PEN fault — and why do EVs care?
A PEN fault happens when that combined conductor is broken somewhere upstream — damaged by roadworks, corroded in an old joint, or failed in a storm. When that happens, the earthed metalwork in your home can rise towards dangerous voltage, because the normal return path has gone.
Inside a house, this risk is reduced because everything you might touch is bonded together at the same potential. The problem with an EV is that the car's body is connected to your home's earth through the charging cable, but the car is standing outside on the ground. Someone touching the car while standing on the driveway could be bridging the gap between a raised "earth" and true earth.
What the wiring regulations say
The UK wiring regulations, BS 7671, deal with this in Regulation 722.411.4.1. In short, a PME earth must not be used for a charging point that is outdoors, or that may charge a vehicle located outdoors, unless one of a set of protective measures is in place. Those measures include a sufficiently low-resistance earth electrode, or a device — which can be built into the charging equipment itself — that detects a PEN conductor failure and disconnects the supply.
The current edition is BS 7671:2018+A4:2026, published on 15 April 2026. The previous version (Amendment 3:2024) remains valid during a transition period that ends on 15 October 2026, after which installers will be working to Amendment 4. The detailed design is your installer's responsibility; the IET's Code of Practice for Electric Vehicle Charging Equipment Installation is the reference most of them use.
Your three options
| Approach | How it works | Pros | Cons |
|---|---|---|---|
| 1. Earth rod (TT for the charger circuit) | A metal electrode driven into the ground gives the charger its own earth, separate from the PME earth | Long-established method; does not depend on the charger | Groundwork, ground conditions, testing, risk of buried services; must be kept separate from house earthed metalwork |
| 2. External PEN fault device | A separate unit between the consumer unit and the charger monitors voltage and disconnects on a fault | No rod; works with chargers that lack built-in protection | Extra hardware and cost; another box on the wall |
| 3. Charger with built-in PEN protection | The charger itself monitors the supply and isolates the output if a PEN fault is detected | No rod, no extra box, simplest install | Your installer must still confirm it suits your installation |
For most single-phase home installs in 2026, option 3 is the default. It is why "built-in PEN protection" has become one of the most important lines on a charger spec sheet.
Why most installers avoid earth rods now
Earth rods are not unsafe — they are a recognised, compliant method. But they bring practical headaches that a built-in solution avoids:
Groundwork. A rod has to go into soil, not concrete or block paving. On a fully paved driveway, that can mean lifting and relaying surfaces.
Ground conditions. The rod has to achieve a low enough resistance to earth. Dry, rocky or sandy ground can make that difficult, and readings can change with the seasons.
Buried services. Driving a rod near gas pipes, water mains or other cables carries a real risk of striking them.
Separation. A TT charger earth must be kept apart from the house's PME-earthed metalwork. Get that wrong and you can create the very touch-voltage problem you were trying to solve.
Time and cost. All of the above adds labour, testing and sometimes a return visit — which shows up on the quote.
When you might still need an earth rod
Your home already has a TT supply. Many rural properties, especially those fed by overhead lines, are already TT — the whole house uses an earth rod. In that case the charger simply uses the existing TT arrangement and PEN fault protection is not the issue.
The charger has no PEN protection. Some chargers, particularly cheaper imports and some commercial units, do not include it. Then you need a rod or an external PEN device.
Three-phase installations. Not every charger's PEN protection covers three-phase supplies. If you are fitting a 22kW unit, check that its protection is specified for three-phase use — several of the commercial units we stock, such as the Evec EDP02-N, explicitly list three-phase PEN protection.
Your installer's design says so. Site-specific factors can affect the decision. If your installer recommends a rod for a particular reason, ask them to explain it — a good installer will.
Chargers with built-in PEN protection
Every charger below lists built-in PEN (or PME) fault protection in its specification. All are 7.4kW single-phase units unless noted.
| Charger | Highlights | Price |
|---|---|---|
| Evec VEC01 (untethered) | PEN protection, no earth rod required; adjustable 3.7kW or 7.4kW | £312 |
| VCHRGD Seven Pro (untethered) | PEN fault protection and 6mA DC RCD; 120A CT clamp included | £380 |
| Indra Smart PRO (untethered) | Built-in PEN fault protection removes the need for external devices | £435 |
| Cord Zero (tethered, 5m or 8m) | PEN fault, surge and over/under-voltage protection; 5-year warranty | £499 |
| Ohme Home Pro (tethered, 5m or 8m) | Built-in PEN protection, no earth rod required; Type A RCD with 6mA DC detection | From £526 |
| Humax MX7 (untethered) | PEN fault, surge and tamper protection; V2G hardware ready | £550 |
| Rolec WallPod (untethered) | TruePEN PME fault protection, no earth rod; MID-approved meter | £925 |
| Rolec EVO 22kW (untethered, three-phase) | PME fault detection removes the need for an earth rod | £469 |
myenergi also builds PEN fault protection into the Zappi, which it says removes the need for an earth rod — see the myenergi range. For the full selection, browse our 7kW home chargers or the OZEV-approved range.
How to check what supply you have
You do not need to open anything — and you should not. The supply equipment near your meter belongs to the network operator and is live.
Look at the main fuse and the area around your meter. Many PME installations carry a label stating that the installation is connected to a PME earth terminal. If there is no such label, a photo of the meter position is usually enough for an installer to tell what they are dealing with. Most will ask for one when quoting.
Common questions
Do all EV chargers need an earth rod?
No. Most modern home chargers include built-in PEN fault protection, which in most single-phase PME installations removes the need for one. Homes with a TT supply already have an earth rod for the whole property.
Is an earth rod safer than built-in PEN protection?
Both are recognised ways of meeting the wiring regulations when correctly designed and installed. Built-in protection is generally simpler to install well, because it avoids the variables of ground conditions and earth electrode resistance.
What does PEN stand for?
Protective Earth and Neutral — the single conductor that carries both functions in a PME (TN-C-S) supply.
How common are PEN faults?
They are rare, but not unheard of — damaged or corroded supply cables do occur. The regulations focus on EVs because the consequences for someone touching a car outdoors during a fault could be severe.
Can I add PEN protection to a charger I already have?
Yes. If your existing charger lacks built-in protection and was installed without a rod, an installer can fit an external PEN fault protection device between the consumer unit and the charger. Ask a qualified electrician to assess the existing installation.
Does the new wiring regulations amendment change anything for homeowners?
For most homeowners, the practical impact is that installers will be working to BS 7671:2018+A4:2026 once the transition period ends on 15 October 2026. Your installer should issue certification to whichever edition they worked to.
Sources and further reading
The information in this guide is drawn from the following sources, checked on 2 October 2026:
| Claim | Source |
|---|---|
| Regulation 722.411.4.1 and the PEN-fault protection options | Amendment 1 to BS 7671:2018, IET Wiring Matters |
| BS 7671:2018+A4:2026 and the transition period to 15 October 2026 | Ensure you are up to date with BS 7671, IET |
| Zappi built-in PEN fault protection | PEN protection, myenergi |
| Charger protection features, prices and specifications | eChargers UK live product catalogue, 2 October 2026 |