Electrical

Section 722: EV Charging Requirements

Name: TradePlanr
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Author: TradePlanr

Section 722 sets the additional rules for EV charging installations. Getting the RCD type and PEN fault protection right is what separates a compliant install from a dangerous one.

Updated 21 Aug 20269 min read

EV charging points sit in Part 7 of BS 7671 as Section 722, because a vehicle being charged outdoors presents a specific set of shock risks. The section modifies the general rules on earthing and RCD protection.

This guide covers the core Section 722 requirements — the RCD type each point needs, how PEN fault protection is handled on a PME supply, and the earthing options you can use.

Key takeaways

Each charge point generally needs its own dedicated circuit with 30 mA RCD protection.
The RCD must disconnect DC residual current — Type A plus 6 mA DC detection, or a Type B RCD.
On a PME (TN-C-S) supply you must protect against a PEN conductor fault, or provide a separate earth electrode (TT).
Many modern charge units build the required protection in — check the manufacturer's declaration.
An EV point is certified with an EIC plus a charge point commissioning certificate.

RCD protection and DC fault current

An EV charge point requires 30 mA RCD additional protection, and because EV charging can produce smooth DC residual currents that blind a normal Type AC RCD, Section 722 requires protection against DC fault current.

That is met either by a Type B RCD, or by a Type A RCD combined with a device providing 6 mA DC residual current detection — the arrangement most built-in charge unit electronics use.

Don't rely on a Type AC RCD

A standard Type AC RCD can be desensitised by DC and is not acceptable for an EV point — always confirm Type A + 6 mA DC or Type B.

The PEN fault problem on PME supplies

Most UK domestic supplies are TN-C-S (PME). If the combined PEN conductor in the network fails, exposed metalwork — including the car body — can rise to a dangerous voltage. Section 722 requires this risk to be addressed for an EV point.

The two common solutions are a device that disconnects the supply if the voltage between line and earth goes outside safe limits (open-PEN protection, often built into the charger), or installing the charge point on a separate TT earth electrode isolated from the PME earth.

Earthing options

You can use the PME earth if open-PEN protection is provided, either by the charge unit or a separate device. Alternatively you can install a dedicated earth electrode and run the charge point as a TT island, which sidesteps the PEN fault risk but requires a suitably low electrode resistance and correct RCD arrangement.

The right choice depends on the charger's built-in features and the site — read the manufacturer's installation instructions alongside Section 722.

Certifying the installation

The new circuit is certified with an Electrical Installation Certificate, and the charge point itself is commissioned and recorded on a charge point installation/commissioning certificate.

Test the circuit as normal, verify the RCD operation including the DC detection, and confirm the open-PEN or TT arrangement works as designed before handover.

Both certificates in one place

TradePlanr issues the EIC and the EV charge point commissioning certificate together, so the whole handover pack is signed on site.

Frequently asked questions

What RCD does an EV charger need?

30 mA protection that also handles DC fault current — either a Type B RCD, or a Type A RCD plus 6 mA DC detection. A plain Type AC RCD is not acceptable.

Do I need an earth rod for an EV charger?

Only if you are addressing the PME PEN fault risk by running the point as a TT island. If the charger provides open-PEN protection, you can use the existing PME earth instead.

Is an EV charge point notifiable?

Installing the new circuit is notifiable work under Part P, and it needs an EIC plus the charge point commissioning certificate.

From guidance to action

EV charge point certificateCommission and certify an EV charge point on site.Cable sizing calculatorSize the dedicated EV circuit for load and volt drop.