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External cabling and the issues with EV.

Good afternoon, first post so go easy please until I get used to the criticism!

I have for the past few months been working in the domestic sector and planning and designing EV installs. On issue that I come come across often is how we run and install our cables, often the charge point is remote from the property or wanted on a garage 10-15 metres away from the house. 

The main issue being clients do not want their garden or mono block dug up and often catenary wiring is not an option. 

What are the collective thoughts on fixing to a wooden structure such as a fence? 

I draw reference to these regulations but could engineer judgement in day be a factor? 

  • wood preservatives may attack the cable sheath (Regulation Group 522.5 refers)
  • timber fencing is unlikely to be sufficiently rigid (Regulation 522.8.5 refers)
  • the life of timber fencing is likely to be less than that of the cable (Regulation 522.8.1 refers)
  • damage sustained by the fence due to the high winds (may present a risk of electric shock)

I believe collaboration with cable manufacturing companies or even the use of conduit some of the above could be mitigated. 

With Ev and the subsequent demand I feel our industry desperately needs to look at new containment solutions or pursue solutions in fulfilling a clients ask. Safely of course!!! 

Are there any thoughts on this?

Thanks all. 

Parents
  • Well in practice, the cheap thing to do will be to put the charger on, or even inside, the main building and extend the flexible cable the last 10/15m, consider it consumable part, and replace it when it gets damaged.

    In some ways, as well as meeting the £500 budget,  this is not as horrible as it sounds. 

    Firstly the cable to the car  is safer and better protected electrically speaking than the one between the consumer unit and the charger, being interlocked with the car and the earth verification  loop,  and even it it wasn't it is dead most of the time, so reducing the chances of being damaged and left live while no-one is about to see it, and also reducing the electricity theft risk. It could even be coiled away when not in use, but probably won't be, but at least it could be coiled up when the fence is blown down, unlike a permanent installation....

    Mike.

  • Good morning Mike.

    The point around the charging cable got me thinking in respects to a possible - retraction system for the cable. This would need to be designed with a limit on the cable charging while any of it is still coiled but it is still a very good idea around using the lead.

    Thanks Mike. 

  • you might need a slightly tougher lead for semi-permanent exposure to the outside world - if it might get run over for example, but a longer 'hose-like' lead  also solves the problem of shared parking and not always being in the same one of half a dozen adjacent  bays. An all cores extension protected with  something like SY braid and a break detector would probably do.


    There are ways of coiling and retracting flexible cables that allow free airflow between the turns, effectively skeleton reels with grooved cable guides, to give an open winding  and in extremis these can be air blown or even liquid cooled.

    (You can also do clever things to the cable - I have worked on some funny stuff over the years including one that had provision for running  cooling water tubes within the (rather hot) cable construction, so I tend not to be so phased by things that others look at askance)

    Mike

  • Fantastic Mike - thanks again for this insight.

  • extend the flexible cable the last 10/15m, consider it consumable part, and replace it when it gets damaged.

    So, yes a technically feasible solution, but this approach is deprecated in guidance, because of:

    • trip hazards (sectors like postal & delivery services, sometimes accessing properties in poor lighting conditions in the dark have reported issues)
    • accessibility issues, and making access more difficult for wheelchair users etc

    In workplaces, such issues are required to be considered for CDM.

  • I'm assuming it follows the route along the fence or whatever that the fixed wiring would, and not violin string tight diagonally across the path - though I agree if you do this method that allows that to be done.

    But In reality at the shallow end where there is no charger at all, I expect to see extension leads out of upstairs windows of terraced houses as a pragmatic if rather ugly way to cross the pavement. After all washing lines have been doing that sort of thing for years in some cities. (probably not the nicer ones down south though ) and where it happens it is not always peaceful co-operation - as this tale of argument and sawn off washing line hooks tells.

    Mike.

    PS Leeds quite recently

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  • I'm assuming it follows the route along the fence or whatever that the fixed wiring would, and not violin string tight diagonally across the path - though I agree if you do this method that allows that to be done.

    But In reality at the shallow end where there is no charger at all, I expect to see extension leads out of upstairs windows of terraced houses as a pragmatic if rather ugly way to cross the pavement. After all washing lines have been doing that sort of thing for years in some cities. (probably not the nicer ones down south though ) and where it happens it is not always peaceful co-operation - as this tale of argument and sawn off washing line hooks tells.

    Mike.

    PS Leeds quite recently

Children
  • Great story Mike. I couldn't help but look on google streetview of the back streets of Skipton, yes the washing lines are still there:- https://www.google.com/maps/@53.9586596,-2.0351512,3a,75y,13.81h,93.62t/data=!3m6!1e1!3m4!1sd59uuEhuYYyXDDaZervfTw!2e0!7i13312!8i6656

    Back to the original question, have you considered putting the cable in unistrut? - self supporting, into/onto the ground if necessary, can then provide a mounting for the "charger". In that case you will probably end up holding up the fence :-). In industry it is used quite a lot for single cable runs that are awkward or small spans, just put the SWA inside - looks neat. Don't know about domestic use though.

    I seem to remember there are very strict limits on the cable length between car and charger?

  • Very interesting point there Roger re the uni strut - I have mounted chargers on strut before but the cable was ran in ducting.

  • That was interesting. Skipton heh, not very far from where I live. Often visit. I know around here, in my childhood days,  it was tradition for every week that one day (Monday I think) it was allowed that washing was hung out in the back street. It was often stated that "it was the law" say local bye laws etc etc. But whether this was just folklore or custom and practice I have no idea. There is a town near me where a couple of streets do it everyday and it`s been happening for years somehow