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Simultaenous Contact

Dom

Good afternoon all, 

I am seeking the collective views of the group regarding the issues we are currently encountering within the EV installation environment in relation to simultaneous contact.

In simple terms, we are seeing a significant number of installations where customers have lamp posts located within their driveways. In many of these cases, it is not possible to achieve the recommended 2.5‑metre separation distance.

My position is that, where physical separation cannot be achieved, the application of layered protection at the EV charge point and associated switchgear would leave the customer in no worse position than prior to the installation. It is accepted that the proposal only outlines protection on the vehicle, but there are no other solutions for industry, are we with the protection detailed taking enough measures to carry out an install and in affect leave the install without a subsantial increase in risk?

My proposed approach to managing simultaneous contact risk would follow a structured hierarchy as set out below:

  • Can the maximum separation distance be achieved?
  • Can barriers or enclosures be installed to prevent simultaneous contact?
  • If neither of the above options are achievable, can layered protection provide an acceptable level of risk mitigation?

With layered protection, the proposed measures would include:

  • Installation of a compliant open‑PEN (O‑PEN) protective device
  • Provision of a double‑pole 30 mA Type A RCBO
  • Use of a charge point - M3 21 mA protection

Based on the above, the assumption is that, if all protective measures are correctly installed and verified, the installation would incorporate:

  • Automatic disconnection within the required times
  • Residual current protection
  • Open‑PEN fault detection

This combination of protections would significantly reduce the likelihood of a fault condition persisting for any meaningful duration.

On this basis, the key question for consideration is:

Where physical separation and barriers are not achievable, would it be considered acceptable to proceed with installation relying on this layered protection approach?

Parents
  • 0
    Dom said:

    This is the kind of issue we are seeing folks.

    The recommended approach here is to contact the DNO/IDNO and ask them if the two properties and lighting column are connected to the same earthing system before deciding on anything. With cross-pavement charging, this is only going to be a more frequent issue.

    In this particular case, I'm guessing it may well not be permitted to erect a fence or barrier due to either planning constraints, or covenants or other terms in the deeds.

    As a last resort, A722.5 provides a solution, but it's not cheap, might have inrush issue, and might take a lot of space.

    At the end of the day, BS 7671 (and HD/IEC 60364 series) had the provision well before work was started on EV charging standards, so I'm up for saying this is not necessarily a BS 7671 issue, but the EV charging standards agreeing on Class I rather than Class II for the LV charging system ?

  • 0 in reply to gkenyon

    Our process is to contact the DNO to confirm the earthing system, however we are now in a posistion where the DNOs are saying this is the responsibilty of the installer rather than the DNO and they are unable to support. I am unsure if this is down to the fact there are to many asks on them at present.

  • 0 in reply to Dom

    Yes, they might be finding the demands difficult ... but the installer can't determine the answer any other way. 

    I do sympathise.

  • 0 in reply to gkenyon

    In terms of looking at the EV COP risk assessment - step 3. Where we have a tethered charge point of say 5 metres, would it be deemed safe to say that if we add the distance of charger lead, the EV car (max UK size) and then the 2.5 metre distance that this would be sufficient precaution? I appreciate that car type can change but by taking this into account have steps been taken to matigate that risk?

  • 0 in reply to gkenyon

    Can ESQCR 2002 help?

    R.15 obliges a DNO to keep a map of underground parts of the network and to make it available for inspection, etc.

    R. 28 obliges a DNO to state the type of earthing system.

    Both are available to somebody who has reasonable cause, which I feel sure must apply.

  • 0 in reply to Dom
    Dom said:
    Where we have a tethered charge point of say 5 metres, would it be deemed safe to say that if we add the distance of charger lead, the EV car (max UK size) and then the 2.5 metre distance that this would be sufficient precaution?

    What is the maximum length of a UK car? You certainly can't go off the standard UK parking space size of 4.5 m, as many SUVs exceed that length.

    I believe (but you'd have to check) that a car can be up to 12 m long in theory.

    And do we need to consider the trailer/caravan, especially if it is plugged into the car and so the chassis of the trailer or caravan is at the same potential as the vehicle body? I believe the total length then increases to 18.75 m for some vehicles?

    However, many large vans and similar are also present on private driveways.

    Finally, if the charging point is being installed according to Part S of the Building Regulations, or the particular provisions of the Scottish Technical Handbooks, tethered charging equipment doesn't appear to be permitted.

  • 0 in reply to gkenyon

    Thank you Graham,  

    I have reviewed the requirements under Part S and the Scottish Technical Handbooks previously, and I cannot find any explicit prohibition on the use of tethered EV charge points. The regulations are focused on the provision of compliant charging infrastructure, rather than prescribing whether the unit must be tethered or untethered. While I recognise that there may be a design preference toward socketed (untethered) units to support flexibility and futureproofing, this appears to be guidance-led rather than a specific regulatory requirement. On that basis, I would welcome clarification on the justification for stating that tethered equipment is not permitted, including the specific clause being referenced from the Scottish JIB themselves?
  • 0 in reply to Dom
    Dom said:
    I have reviewed the requirements under Part S and the Scottish Technical Handbooks previously, and I cannot find any explicit prohibition on the use of tethered EV charge points.

    Here is the requirement for untethered charging points in black and white in the SBSTH Domestic (April 2026):

    And the non-domestic of April 2026:

    Whilst there is no 'prohibition' there is a clear requirement for it to be untethered in Scotland.

    And in AD-S:

    There is a clear requirement for untethered, with the option for tethered only in exceptional circumstances (e.g. self-build and where the vehicle requirements are already known - since people change their vehicles, or have more than one, I'm not sure how "firm" one could be about the exception).


    BUT ... this is only for charging points provided specifically where required by Part S or the Scottish Technical Handbooks ... if you are providing one when it's not required by Part S or the handbooks, or for general public use, that's another question.

    This is all covered in the 5th Ed of the IET Code of Practice for Electric Vehicle Charging Equipment Installation.

  • 0 in reply to gkenyon
    gkenyon said:
    I believe (but you'd have to check) that a car can be up to 12 m long in theory.

    And do we need to consider the trailer/caravan, especially if it is plugged into the car and so the chassis of the trailer or caravan is at the same potential as the vehicle body? I believe the total length then increases to 18.75 m for some vehicles?

    Not sure about that. Even an extended Rolls-Royce Phantom is just under 6 m, but the space to park it in is likely to be more than average. I suppose that there are stretched limos, but they may be too heavy for an ordinary car driving licence, and unlikely to be parked in front of an average semi.

    That's why I suggested a motorhome earlier.

Reply
  • 0 in reply to gkenyon
    gkenyon said:
    I believe (but you'd have to check) that a car can be up to 12 m long in theory.

    And do we need to consider the trailer/caravan, especially if it is plugged into the car and so the chassis of the trailer or caravan is at the same potential as the vehicle body? I believe the total length then increases to 18.75 m for some vehicles?

    Not sure about that. Even an extended Rolls-Royce Phantom is just under 6 m, but the space to park it in is likely to be more than average. I suppose that there are stretched limos, but they may be too heavy for an ordinary car driving licence, and unlikely to be parked in front of an average semi.

    That's why I suggested a motorhome earlier.

Children
  • 0 in reply to Chris Pearson

    haha 12m is ther upper bound for box lorries and similar and is the same as  a normal bus or coach,though a large bus may be up to 13,5m or even 15 m if it has a double back axle. - which might in principle be pulling  a trailer of up to the same length.

    More commonly for the general public, those of us with the pre-millenium car licence can drive a 7.5 Tonne lorry (12m max ) towing a trailer to a maximum train weight of just under 13 tonnes but there is a total train limit, for a Motor vehicle drawing one trailer (which is not a semi-trailer) of  18.75m, and the longest common trailer for a car is 7m, or 12m behind a heavier vehicle... 
    see https://www.gov.uk/government/publications/maximum-length-of-vehicles-used-in-great-britain/maximum-length-of-vehicles-used-in-great-britain 

    But that is a silly argument, if the driveway is shorter, that becomes the limiting factor for a vehicle charging on the drive.  There are mercifully few of these maximum length cars on the road actually. (Acknowledgement to "top gear" for actually making a 12m car out of a Fiat Panda, even if it never survived its first outing. )

    Mike

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