If you’re installing an EV charger or upgrading a supply, the same question keeps cropping up: do you still need to bang in an earth rod if you’ve got a PME fault detection device?

The short answer is: not usually. The 18th Edition Amendment 2 (BS 7671:2018+A2:2022) sets out clear rules on when a rod is needed, and modern PME fault protection devices are designed specifically to remove that requirement in most EV installations.

What PME Fault Protection Does

PME (Protective Multiple Earthing) fault detection devices monitor the supply and disconnect all live conductors and the earth if a PEN (Protective Earth and Neutral) fault is detected.

• This prevents dangerous touch voltages on exposed metalwork.
• It can avoid the need for a separate earth electrode in many EV installs.
• Units are available for single‑phase and three‑phase setups, including IP65 PEN fault detection units and 3‑phase PME boards.

In practice, a PME device trips faster and more reliably than relying on a local earth rod, which often has high resistance or poor ground conditions.

When You Still Need an Earth Rod

There are cases where PME alone isn’t enough, and a rod (or multiple rods) is still required:

• TT systems – no PME available, so you must provide a local electrode.
• Some DNO conditions – certain Distribution Network Operators still request a rod as belt‑and‑braces.
• Legacy installs – older consumer units without integrated PME detection.
• Non‑EV circuits outdoors – e.g. garden supplies, where PME may not be permitted.

For most EV charger installs, however, a compliant PME fault device removes the earth rod requirement entirely.

PME vs Earth Rod – Why It Matters for EV

The challenge with earth rods has always been reliability:

• Soil conditions vary wildly (clay, sand, chalk).
• Resistance values can change with weather and moisture.
• Testing rods adds extra time and cost to the job.

PME devices solve that by providing a self‑contained, regulation‑compliant disconnect that satisfies DNOs and BS 7671. That’s why they’ve become the go‑to option for EV installers needing fast sign‑off.

Products That Deliver

If you’re speccing an EV job and want to avoid rods, look for:

• PEN/PME fault detection units (often IP65‑rated, single or three‑phase) – e.g. the PEN Fault Detection Unit – IP65 with Load Balancing Relay.
• PME‑ready consumer units that combine RCBOs and RCDs with built‑in PEN detection – e.g. the PME Plastic Consumer Unit – 40A RCBO + SPD.
• Load balancing PME boards for multi‑charger or high‑demand sites, and 3‑phase PME units for multiple charge points.

These units are specifically marketed as “no earth rod required” - giving you confidence on site and cutting install time.

Final Word

So, do you still need an earth rod with PME fault protection?

• For most modern EV installs – no.
• For TT or non‑PME systems – yes.

The key is matching the board or protection device to the supply type and ensuring it’s 18th Edition Amendment 2 compliant. That way you’ll avoid callbacks, pass inspection first time, and keep your installs neat and safe.

Next step: Explore our PME fault detection range, EV‑ready consumer boards, and PEN devices to see which suits your install.