Summary:
Tesla Wall Connectors are among the most popular EV chargers in the UK, but many models don’t include built-in PEN fault detection. This post explains what PME protection means for Tesla installations and how to stay compliant under BS 7671 with the right standalone solutions.
Why Tesla Chargers Need PME Protection
Tesla Wall Connectors are sleek, smart, and reliable — but one thing they don’t always include is PEN fault detection.
That’s a crucial detail for installers because Regulation 722.411.4.1 of BS 7671 (18th Edition + Amendment 2) requires EV charge points to disconnect automatically in the event of a PEN fault on PME systems.
Without that protection, a lost neutral can raise the car body voltage dangerously high — posing a shock risk.
What Is a PEN Fault?
In a TN-C-S (PME) system, neutral and earth are combined in the supply cable.
If the neutral is lost (the “PEN conductor”), the potential difference between neutral and earth can rise to 230 V — enough to make exposed metal parts live.
PEN fault detection units constantly monitor voltage levels and automatically disconnect the load when they detect unsafe conditions.
The Tesla Wall Connector & PME Compatibility
Tesla Wall Connectors (Gen 3) include built-in DC leakage detection, but not PME fault protection.
This means installers must either:
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Convert the installation to a TT earthing system, or
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Fit a dedicated PEN fault detection device upstream.
Most installers prefer the second option — faster, cheaper, and fully compliant.
The Ideal Solution – 3-Phase PME Protection Unit
The 3-Phase PME 40A RCBO + Surge Protection Unit from Eco Harmony offers everything you need for Tesla installs:
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✅ 3-Phase PEN Fault Detection
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✅ 40 A RCBO per charger
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✅ Type 2 Surge Protection (SPD)
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✅ IP40 metal enclosure
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✅ Fully BS 7671 A2:2022 compliant
It’s available in versions supporting 2, 3, or 6 chargers — ideal for domestic, fleet, or multi-bay Tesla setups.
Why Installers Prefer This Setup
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No TT Conversion: Keeps things simple on PME supplies.
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Pre-fitted & Pre-tested: Less wiring time on site.
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Compatible with Tesla & most other EV chargers.
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Compact metal enclosure (IP40): Easy wall mount and clean appearance.
It’s the same high-quality WCED build trusted by UK installers for reliability and compliance.
Example Installation
An installer recently fitted three Tesla Gen 3 chargers on a commercial 3-phase supply.
They used the Eco Harmony 3-Phase PME Unit with three 40 A RCBOs — and passed NICEIC inspection without issue.
Everything was wired cleanly, SPD integrated, and PME protection verified with a PEN fault simulator.
Bonus: Protect More, Spend Less
If you’re building a multi-charger setup, pair the PME protection unit with a TPN Distribution Board + SPD — and get 25 % off MCBs when purchased together.
Conclusion
Tesla chargers are among the best on the market — but they still need PME fault detection for UK compliance.
By using an integrated 3-Phase PME Protection Unit with RCBO and SPD, you can ensure every install is safe, compliant, and inspection-ready.
👉 Explore Tesla-Compatible PME Protection:
https://ecoharmony.co.uk/products/3-phase-pme-40a-rcbo-surge-protection