EV Car Charger

Discussion in 'Electricians' Talk' started by jackSwan, Nov 25, 2021.

  1. jackSwan

    jackSwan New Member

    Hi All,
    I'm looking to get a 7kWh car charger installed. The CU is in the garage and the wire to the charger will run 100% inside the garage (about 10m) before exiting through the wall directly into the back of the charger.
    The cable will be visible and cliped to the garage wall throughout the run.
    Is it necessarsy for the cable to be armoured, or is it OK to opt for 6mm twin and earth, insulated in the usual rubber? The difference is approximately 100quid and I don't want to spend that extra if it's not necessary.

    Thanks for any contribution.
  2. MGW

    MGW Screwfix Select

    Up to your installer, likely does not need SWA, but down to whoever signs the installation certificate.
  3. jackSwan

    jackSwan New Member

    Thanks :) I'm trying to make sure I don't have to have something I don't need! I've been stung before where I've been told I need something I don't, just because there's a bigger mark up on it and not profit in it for the installer/engineer.
  4. Comlec

    Comlec Screwfix Select

    I think you have proved your own point by buying an EV :)

    But as @MGW says leave it up to your installer. IMHO a neatly installed run of SWA is far smarter a bit of T&E tacked to a wall.
  5. The Happy Builder

    The Happy Builder Screwfix Select

    So we will buy an expensive car, but quibble over the cost of a length of cable for the charger.
    nigel willson likes this.
  6. pppmacca43

    pppmacca43 Super Member

    Bit of a strange comment. Nobody wants to be ripped off and pay for things you don’t need.
  7. Comlec

    Comlec Screwfix Select

    Not strange at all. I thought it just shows that value is subjective. I am sure Tesla owners didn't feel ripped off as they watched Mr Musk take his annual holiday to the the von Kármán line
  8. pppmacca43

    pppmacca43 Super Member

    Don’t really see what any of that has to do with the OPs question but there you go. He doesn’t want to be ripped off an pay for something he don’t need so asks a sensible question and gets chastised for having an electric car :rolleyes:
  9. Lectrician

    Lectrician Screwfix Select

    Cables run within a garage should have additional protection where accessible. However, T&E in trunking or conduit would fine, clipped direct at high level to trusses etc.
    pppmacca43 likes this.
  10. MGW

    MGW Screwfix Select

    It seems where I work the EV charger (22 kW) charges for 15 minutes while you sort out the payment with the app. It is designed so car starts to charge right away, reducing time at charge point, but we have caught people sitting in their car unplugging the lead every 15 minutes and plugging it back in to steal the 5.5 kWh. OK cost the charity I would for likely less than £1, but come on it's a charity and they are stealing money from a charity, how low can you get? Same are when the church collection comes around taking a pound from the plate.

    The big problem with EV charging points is danger from touching vehicle when using a TN-C-S supply and freezing the RCD with DC, we do have methods to stop it, but where people penny pinch on cable one has to ask where else?
  11. The Happy Builder

    The Happy Builder Screwfix Select

    The cable could still be use in fifty years from now and out last a considerable number of cars, perhaps you have not got your priorities right.
  12. The Happy Builder

    The Happy Builder Screwfix Select

    Perhaps someone will do the sums, potentially the cost saving of using a 10 mm cable rather than a 6 mm cable could be significant over the life of the cable, because a smaller cable may heat up and increase the meter reading.

    It’s not always a good idea to try and scrimp on installation materials and generally you are better off paying for a quality job.
  13. The Happy Builder

    The Happy Builder Screwfix Select

    Also your estimate of the cost difference between the installed cables is way out, 10 metres of 6 mm SWA is less than £40, so even with the fixings and glands there cannot be a hundred quid price difference between SWA and T&E.
    Last edited: Nov 26, 2021
  14. The Happy Builder

    The Happy Builder Screwfix Select

    It might even be possible to drop down a size to 4.0 mm, but again all aspects of the design need to be considered including the “running costs” of the cable.
  15. jackSwan

    jackSwan New Member

    This is a strange and unrelated comment, as others have indicated.
    Even if I spent 100k on a car, that's my choice, and it's also my choice not to be ripped off by the wire choice.

    Your comment is ignorant. Perhaps I didn't pay for my car at all ... Perhaps I was gifted it by a friend who died... Perhaps it's 100% provided by work.

    Perhaps I paid for it outright and can afford to do so because I make sure I don't waste money day to day.

    You know nothing about me, so if you want to contribute to the forum in a meaningful way, then do so by answering the question. You just come across as a jealous Micra driver!
    pppmacca43 likes this.
  16. Comlec

    Comlec Screwfix Select

    I just bought a Micra and I am offended by your comment.

    @jackSwan you have been advised by the professionals, who freely give their time and expertise on this forum, to leave the specifics of the installation to a certified EV installer who will choose the most appropriate method for an installation that will be safe and compliant.

    If you are concerned by being 'ripped off' then you could try the age old method of multiple quotes for a variety of installers. You will then be able to make an informed choice based on surveys. And if you are quick you could still get the Tax Payer handout to subsidise you install.
    Grant schemes for electric vehicle charging infrastructure - GOV.UK (www.gov.uk)

    And people wonder why I don't do EV or Ring installs:)
  17. The Happy Builder

    The Happy Builder Screwfix Select

    I do occasionally drive a Micra, though I don’t actually own one.

    You thanked us in advance for “any contribution” now you’re moaning about what has been said.

    The cable running through the garage will presumably need protection against possible damage at some point in its run, so using soft skinned twin and earth rather than SWA will possibly increase the overall cost of the job due to having to install additional mechanical protection.
    Using a smaller size of cable may reduce the initial cost, but over the many hours and years it will be used it may significantly increase your electric bill due to running hotter than a larger size of cable, heat that has to be paid for.
    The cost of the cable is utterly and completely insignificant compared to the cost of purchasing the car, just pay for the most appropriate cable for the job and don’t think twice about the cost of it, it will outlast both the current car and charger that will be bought and installed, indeed the cable may still be in use in fifty years time unlike the current car and charger.
    Just because an electrician may suggest using a better cable than twin and earth does not mean they are trying to fleece you and con you out of money, there’s more than one reason for doing so.
    The difference in cost between SWA and T&E will not be a hundred quid, anyway chances are you are expecting me as a taxpayer to subsidise it for you; and as an electrician to do the job ASAP, but not get paid for doing so until half way through next year :rolleyes:

    I’m sorry if you think that electricians are rip off merchants who are out to sting you, but you did post your question on a forum asking for comments from electricians and that’s what you got.
  18. Bazza-spark

    Bazza-spark Screwfix Select

    Although a 7kW charger may suit your requirements now, it may well be undersized in a few years time and you will end up redoing the entire circuit.

    As @The Happy Builder has pointed out, the difference in cable cost will be marginal, but also if you add the cost of conduit or trunking to give you the physical protection for your cable your existing solution becomes more expensive.

    Your money, your bills and your choice, but you have been given genuine professional advice free of charge.

    By the way, the cable is PVC not rubber.
  19. Jimbo

    Jimbo Screwfix Select

    I suppose the OP might have been referring to Tuffflex.
  20. Bazza-spark

    Bazza-spark Screwfix Select

    You may be correct, but he stated T&E as you see.

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