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Have your say on the Electrician’s Guide to Domestic Electric Vehicle Charging Equipment Installation

Stanley Walton

The Draft for Public Consultation (DPC) is available for the IET’s Electrician’s Guide to Domestic Electric Vehicle Charging Equipment Installation. This is your opportunity to review the draft and provide feedback to help ensure the publication meets the needs of electricians, designers, installers and other professionals working with electric vehicle (EV) charging equipment. 

As EVs become increasingly common across the UK, the demand for safe, and compliant charging installations continues to grow. This guide has been developed to provide practical guidance on the selection, design, installation and certification of domestic EV charging equipment, helping practitioners navigate the technical and regulatory requirements associated with this rapidly evolving sector. 

What the guide covers 

The draft publication provides a comprehensive overview of domestic EV charging installations, including: 

  • The various EV charging modes and types of charging equipment 
  • Relevant regulations, standards and key sources of information 
  • Assessment considerations before system design and installation 
  • Methods of electrical protection and earthing 
  • Domestic and small commercial installation design, including control devices, circuit design and cabling 
  • Certification and documentation requirements 

Bringing together essential technical guidance and industry best practice, the guide is intended to support both experienced electricians and those new to EV charging installations. 

Why your input matters 

The DPC provides an opportunity for industry professionals to help shape a practical and authoritative resource for the electrical sector. Whether you are involved in EV charger installation, inspection and testing, electrical design, training or compliance, your feedback can help ensure the guidance remains relevant, accurate and aligned with current industry practice. 

Your comments will help strengthen the final publication, supporting safer installations and promoting consistency across the growing EV charging market. 

Visit the website to find out more and submit your comments by 21 August 2026: https://spkl.io/600073To0

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  • It makes a lot of training courses, qualifications and manufactures installation instructions look unfit for purpose.

  • in reply to Simon Barker

    Hi

    EVSE is switchgear, not a load.  Providing you are operating it within its voltage rating then usually the interesting parameter for switchgear is its current rating.  We don't rate CUs in kW so I'm not sure why we do that for EVSE.

  • in reply to DShutt
    DShutt said:
    As per my comment in the "Electricians in the real world" thread my understanding is that AC EV charging is a constant current load, not constant power.

    Yes, that is also my understanding. If correct, it needs someone to respond on the DPC form. 

  • in reply to DShutt

    Interesting point. However a lot of the regs try to take a 'simplified view' [rather than a let's over complicate this view], which leaves many making assumptions about how loads are to be assessed.

    Plus, as you say, the EVSE isn't a load, but the EV behind it is a load, and the confusion is over the way the wiring to the EVSE should be selected and spec'd, especially when others keep following the 'loads are in kW' primary expectation...

  • in reply to Chris Pearson
    Chris Pearson said:
    but if you go for a 40 A MCB (or RCBO) you now need 6 mm2.

    Not necessarily - it's still permitted to handle overload and faults separately - if the EVSE provides overload protection, the cable still need only be sized for 32A provided it's c.s.a. has enough withstand for the B40 fault clearance (54000 A²s for a 6kA device - or just over 2mm² Cu for k=115). (double check the c.p.c. though if T&E)

       - Andy.

  • in reply to lyledunn
    lyledunn said:
    If correct, it needs someone to respond on the DPC form. 

    Good call. I've already sent my response last night (and hadn't noticed that) ... any volunteers?

       - Andy.

  • in reply to DShutt
    DShutt said:
    We don't rate CUs in kW so I'm not sure why we do that for EVSE.

    Probably a consumer/marketing thing. EV owners will know their EV batttery capacity in kWh, so it's simpler for them if the charge rate is in kW - e.g. 72kWh EV and 7.2kW charger = 10 hours for a full charge.

    Who installs 7.4 kW EVSEs? I though the maximum standard rating was 7.2 kW.

    I guess it's a bit like showers - it all depends on the voltage you assume  ... 32A is 7.68kW at 240V, 7.4kW at 230V and 7.2kW 225V (presuming PF=1) - allowing 5V v.d. within the installation probably isn't unrealistic.

       - Andy.

  • in reply to AJJewsbury
    AJJewsbury said:
    Probably a consumer/marketing thing.

    Possibly ... the product standard for charging equipment permits the manufacturer to quote rated power or rated current.

  • in reply to DShutt

    I believe that while we commonly say how many kW a charger is, the EVSE tells the car how many amps it's allowed to draw.

    If I log into my EVSE through its app, I can set the maximum current the car is allowed to draw. I have mine set to 22A (for reasons*), which means that the car draws about 5 kW maximum.

    *A bit of a design flaw on the Renault Zoe. The connector where the charge port wiring loom meets the filter unit has an under-sized neutral. Because nobody would ever charge a car at 32A single phase, would they? Then they started exporting them to the UK, where home chargers, and many destination chargers, are single phase.

  • in reply to Chris Pearson
    Chris Pearson said:
    So is the takehome message that you need to wire your EVCP in 6 mm2 cable?
    AJJewsbury said:
    Not necessarily - it's still permitted to handle overload and faults separately - if the EVSE provides overload protection, the cable still need only be sized for 32A provided it's c.s.a. has enough withstand for the B40 fault clearance (54000 A²s for a 6kA device - or just over 2mm² Cu for k=115). (double check the c.p.c. though if T&E)

    So Andy says, may be, may be not.

    I suspect that the rated diversity factor is more important. After all, if it is as low as 0.5 and the breaker cannot be kept separate from other continuous high loads, a 63A one will be required.

  • in reply to Simon Barker

    Yes, the EVSE signals the maximum available current to the EV using the Control Pilot pin in the charging cable, the EVSE can then operate upto that limit, as required.

    That current limit signal, depending on the EVSE hardware and the installation, can be used very simply as a fixed limit, or it can be varied dynamically to provide smart charging functionality, to manage the load at the house, or on a circuit, or to control charging to track the output from solar generation to self-consume solar, or for smart charging with time of use tariff.

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  • in reply to Simon Barker

    Yes, the EVSE signals the maximum available current to the EV using the Control Pilot pin in the charging cable, the EVSE can then operate upto that limit, as required.

    That current limit signal, depending on the EVSE hardware and the installation, can be used very simply as a fixed limit, or it can be varied dynamically to provide smart charging functionality, to manage the load at the house, or on a circuit, or to control charging to track the output from solar generation to self-consume solar, or for smart charging with time of use tariff.

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