EV Charging Guides

📚 Technical Guides · UK EV Charging · BS 7671

EV Charging Guides

Everything you need to understand UK EV charging — from PME protection and BS 7671 compliance, to choosing between charger models, upgrading existing units, and specifying the right protection devices. Written for homeowners, installers, and OEMs.

15 guides · Regularly updated

🧠 Expert knowledge since 2012

🧠Expert technical advice since 2012 💷Competitive trade prices 📦Volume & OEM discounts 🚚Fast UK dispatch

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Who these guides are for

Homeowners — plain English explanations of what PME is, whether you need an earth rod, and how to choose the right charger for your home. Installers & electricians — deep technical detail on BS 7671 Section 722, protection device selection, and compliance routes. OEMs & developers — EPC controller architecture, modular system design, and volume supply information.

🏠 Homeowner — I want plain English

🔨 Installer — I need the technical detail

🏭 OEM / Developer — I’m building systems

PME Protection & Earthing 6

The most technically complex area of UK EV charging — and the one with the most misconceptions. These guides cover PME (TN-C-S) supplies, earth rods, WCED boards, and how to achieve BS 7671 Section 722 compliance.

PME fundamentals

What is PME in EV Charging?

TN-C-S supplies, PEN conductors, and why ~80% of UK homes need specific EV fault protection. Start here if you’re new to PME.

→ Earth rod decision

Do I Need an Earth Rod for an EV Charger?

The definitive installer decision guide. Spoiler: in most modern UK installs, no. Here’s why — and when one is still required.

→ WCED boards

PME Protection Devices Explained

How WCED boards detect PEN faults electronically and replace earth rods. What’s included, how they’re wired, and why they’re faster to install.

→ Protection layers

PME vs RCD vs RCBO vs RDC-DD

Four distinct fault types, four distinct protection layers. Explained clearly — what each device does and why no single device covers everything.

→ Integrated protection

Simpson & Partners: Do They Need an Earth Rod?

Why Simpson & Partners chargers have integrated PEN fault detection — and what this means for installation time, cost, and compliance.

→ WCED boards deep dive

Fully Assembled WCED Boards Explained

What’s inside a fully assembled WCED consumer unit, how the components work together, and why pre-assembled saves installation time and reduces errors.

→

Simpson & Partners EV Chargers 3

UK-designed and manufactured EV chargers with integrated PME protection, right-to-repair design, and genuine smart energy capability. These guides cover the full range from model selection to feature deep dives.

Buyer guide

Basic vs Plus — Full UK Buyer Guide

Charging speed is the same. The differences are in energy management, solar integration, smart tariff support, finishes, and future-proofing. This guide breaks it all down.

→ Feature deep dive

Key Features Explained

Right to repair, 5-year warranty, Octopus Intelligent, V2G readiness, OCPP, dynamic load balancing, and in-house UK software — everything that sets them apart.

→ Installation

Do They Need an Earth Rod?

No — but here’s the technical explanation of why, and what protection is still required. Essential reading for installers specifying on PME supplies.

→

EVSE Controllers & Upgrading 2

Most EV chargers don’t fail — they become outdated at the control level. These guides explain EPC controllers, modular charging systems, and how to upgrade existing chargers (including Rolec) without full replacement.

EPC fundamentals

What Is an EVSE Protocol Controller (EPC)?

The brain of every EV charger. Why it becomes outdated faster than everything else — and why a modular EPC-based approach changes what’s possible.

→ Upgrade vs replace

Upgrade or Replace Your EV Charger?

Why replacing the whole charger is usually wrong when only the control system is outdated. The smarter alternative — and who it suits.

→ Rolec specific

How to Upgrade a Rolec EV Charger

Step-by-step guide to retrofitting an EPC controller into a Rolec unit. Keep the enclosure and cable, replace the brain — modern features for a fraction of the cost.

→

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Ready to buy? EcoHarmony stocks everything covered in these guides

From fully assembled WCED PME boards and Simpson & Partners chargers to EPC controllers and three-phase distribution boards — all UK-stocked, all at competitive trade pricing.

💷 Competitive pricing — volume discounts from 5+ units for installers and OEMs
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🧠 Expert advice — we’ll help you specify the right product for your scenario

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Integrated PME protection · 7kW & 22kW

Simpson & Partners EV Chargers

Built-in PEN fault detection, right-to-repair design, Octopus smart tariff support. No earth rod, no external WCED board on PME supplies. Basic and Plus ranges.

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PME + RCBO + SPD · Single-phase

Single-Phase WCED PME Boards

Fully assembled external PME protection for any standard EV charger on a TN-C-S supply. Includes all required protection layers pre-built and tested.

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22kW · Three-phase

Three-Phase WCED Boards

Three-phase PME protection + RCBOs + SPD for 22kW commercial and high-power domestic EV charging installations.

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Retrofit · Smart features · OCPP

EPC Controllers

EVSE Protocol Controllers for retrofit upgrades and new build. Add app control, load balancing, and smart tariff support to existing charger enclosures.

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Tesla, 3-Phase & Heat Pump Installs 4

Higher-complexity installs that require specific protection devices. Tesla Wall Connector on PME, three-phase RCBO and SPD specification, commercial distribution boards, and heat pump Type B RCD requirements.

Tesla & PME

Quick Reference — Common Questions

Question	Short answer	Full guide
Does my UK home have a PME supply?	Probably yes — ~80% do	What is PME? →
Do I need an earth rod for my EV charger?	Usually no — modern protection devices replace them	Earth Rod Guide →
What is a WCED board?	PME protection + RCBO + SPD in one unit	WCED Explained →
Does an RCBO provide PME protection?	No — different fault type entirely	Protection Layers →
Do Simpson & Partners chargers need a WCED board?	No — protection is built in	S&P PME Guide →
Basic vs Plus — which should I choose?	Plus if you have solar; Basic for standard charging	Buyer Guide →
Can I upgrade my old charger instead of replacing it?	Usually yes — replace the control system only	Upgrade Guide →
What is an EPC controller?	The brain of an EV charger — the part that gets outdated	EPC Guide →
Can I upgrade a Rolec charger without replacing it?	Yes — retrofit an EPC controller	Rolec Upgrade →
What PME protection does a Tesla Wall Connector need?	Same as any other EV charger — 3-phase PME board on a 3-phase supply	Tesla Guide →
What RCBO do I need for a 3-phase EV charger?	40A Type A RCBO — one per charger circuit	3-Phase Guide →
Can I use a Type A RCD on a heat pump?	No — heat pumps require Type B minimum	Heat Pump Guide →