Op-ed: The importance of a standardised approach for EV charging point faults

Posted on 11 Oct 2024 by The Manufacturer

With EV uptake on the rise in the UK, Mark Coles, Head of Technical Regulations at the Institution of Engineering and Technology (IET), explains the importance of a standardised approach for dealing with Electric Vehicle (EV) charging point faults on the public low voltage distribution network.

Embracing the EV transition means that these vehicles and the required chargepoints have become commonplace both on-street and outside homes. To meet the UK government’s targets for net zero, many, many more chargepoints need to be installed.

The positioning of chargepoints presents challenges to the designer and installer and must be supported by requirements and methods of operation that ensure the safety of users. These challenges are not going away and, with the demand for more power to charge EVs, the risk of faults is increasing.

Faults

Faults can occur on the supply cables out in the street, such as those cables owned by electrical supply and distribution companies, which are beyond the control of the installation owner or the operator of the charging equipment. These faults on the supply cables can lead to dangerous voltages appearing between the metallic shell of the electric vehicle (whilst it’s on charge) and “Earth”, i.e. the ground that you walk on.

In the UK, the low voltage electrical supply is mostly distributed to our homes and businesses in a TN-C arrangement; C indicates that there is a ‘combined’ conductor in the network that combines both the neutral and protective functions. This is the ‘Protective Earth Neutral’ – or the ‘PEN’ conductor’ for short. If this conductor is severed, due to roadworks or even corrosion, as stated earlier, a dangerous voltage can appear between the ground and any metalwork connected to the electrical installation.

Current confusion

Current regulations require EV charging equipment to cease charging and completely isolate the vehicle from the charging equipment when a particular fault occurs on the supply cable out in the street. Most manufacturers of EV charging equipment provide this functionality, but not all of them do it in the same way.

For example, some manufacturers add in other functionality that may seem helpful, but it’s not always clear whether it is necessary. Others require the installation of an earth electrode to enable the measurement of the electrical potential difference to Earth. It is challenging for electrical installers to choose the right chargepoint for the right circumstances and differing external influences faced at the chosen point of installation. This causes confusion when choosing the most suitable equipment and approach to installation.

A new standard to tackle this

That’s why at the IET, we have developed a new standard to tackle this, known as Open combined protective and neutral (PEN) conductor detection devices (OPDDs), IET 01:2024. It outlines to manufacturers, specifiers, designers and installers the protection mechanisms for EV charging equipment in case faults occur.

The new standard also equips installers with the knowledge needed to choose the right chargepoint for the right circumstances and with considerations towards differing external and environmental influences that may be faced at the chosen point of installation.

The aim is to make it easier for designers and electrical installers to choose a suitable product to meet individual circumstances and requirements. This provides efficiencies for installers and will improve safety for operators and users of EV charging equipment, as well as members of the public.

Industry input

IET 01 has been developed over the course of several years by consensus of a technical committee comprising stakeholders from across industry and facilitated by the IET as part of our commitment to the advancement of engineering excellence. IET 01 is not a static document and will be continually developed through consensus and in response to public feedback and consultation. It is the IET’s ambition for IET 01 to be adopted by those working with EV systems and installations, and to be considered by the relevant regulatory committees.

We want to make it easier for designers and electrical installers to choose a suitable product to meet individual circumstances and requirements. This will provide efficiencies for installers and improve safety for operators and users of EV charging equipment – and ultimately for members of the public.

For more information about IET 01 and to watch the full video interview with Mark Coles, Head of Technical Regulations, IET and Graham Kenyon, independent consultant, as they discuss how the Standard might affect specifiers, designers and installers working in the EV charging area, please visit theiet.org/iet-01.


About the author:

Mark Coles BEng (Hons) MIET, Head of Technical Regulations at the Institution of Engineering and Technology (IET)

Mark Coles served his apprenticeship as an electrician with the UK Atomic Energy Authority and worked on many nuclear projects including the decommissioning of Windscale Piles 1 & 2, decommissioning of the Advanced Gas Reactor (AGR), Cement Encapsulation Plant, commissioning of THORP (Thermal Oxide Reprocessing Plant) and the Auto-Sampling Pneumatic Transfer System at Sellafield, Cumbria.

After studying Electrical & Electronic Engineering at London South Bank University, Mark worked as Contracts and Project Manager in electrical contracting at Canary Wharf, London and then held the post of Operations Engineer with NICEIC.

Currently, Mark is Head of Technical Regulations at the IET and is responsible for the development of BS 7671, IET Guidance Notes and associated Codes of Practice.

Mark is a very experienced standards maker and a leader in standards making. He holds the convenorships of numerous international and European technical committees and is an appointed UK expert on many others, setting standards for low voltage electrical installations across the world.

Mark is also the Committee Manager for JPEL/64, the UK technical committee responsible for BS 7671, Requirements for Electrical Installations, The IET Wiring Regulations.

Mark speaks regularly at industry events, writes articles for the IET publication Wiring Matters and other IET and trade publications.

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