The cable calculation procedure for an EV (Electric vehicle) charger

A basic cable calculation guide, and some comments on installing an EV charge point.
Installing an EV charge point is not that straight forward, and new issues are coming to light all the time.
Guidance is constantly changing, so I think it's important to keep up to date with the changes, and if possible go on a recognised course provided by a reputable trainer. Such as the 2921-31 for domestic or for more complex installs 2921-32 or the 2921-33.

[@no_short_circuit]

As far as videos covering cable size calcualtion go this has to be one of the best for any learner. Clear and understandable principles explained in laymans terms - thank you very much for taking the time to shere your knowledge with us.

[@JPElectric]

Thanks again. Very kind of you to say

[@jollyfinequality9865]

I concur with the first two comments above. A really good breakdown of the necessary steps. Great to follow. Thank you for putting it together.

[@JPElectric]

Thanks for watching jollyfinequality9865 really appreciate it.

[@mb-electricalservices]

I use software to carry out design calculations which is incredibly accurate and great for my clients as a full report can be sent confirming all calculations meet the requirements. The problem with this method is that, as an electrician, you become lazy and lose the ability to manually do the calculations. You've given me a bit of food for thought here because it's clear to me that I have become reliant on software. Thanks for the video. Great stuff for learners and old sparkies like myself. 💪

[@angelofranklin1]

Software is great until the computer breaks down

[@JPElectric]

Thanks very much for watching. I do like to work out with a pen and paper, then I use software to confirm my working out, and visa versa.

[@mb-electricalservices]

@@angelofranklin1 Very true!! Fair point...

[@mb-electricalservices]

@@JPElectric You're welcome bud. 👍

[@Rossisearle]

Been looking forward to next video.. Your layout and drawing are amazing.. very helpful

[@JPElectric]

Thanks very much Rusko_Customs

[@highgatehandyman6479]

Love your vids. Im nearly able to self certify. I understand the principles of solenoid but thought a bs60898 only applied to ac circuits. But you mentioned a type A mcb because of DC currents. I would love you to discuss this topic further. Thanks for these excellent videos

[@JPElectric]

Thanks for the comment. We are talking about AC circuits. But lots of modern tech has electronics which produce DC current, and this can appear on the AC installation. LED lighting, EV charging, Washing machines. Basically anything with an electronic circuit can introduce DC current onto an installation. The standard AC RCD can be 'blinded' by this current i.e be desensitised, so it will not pick up an imbalance in the supply. This is how loop testing was made possible with multifunction testers (Dlock) it saturated the RCD coil with DC current to enable the loop test with out tripping the RCD. Type A RCDs can work with around 6mA of DC current, and are now currently required. AC RCD are all but extinct. Type A is also not ideal, but its what is generally available. This issue will be ongoing for some time

[@highgatehandyman6479]

Ok. Excellent information. Thank you !

[@ja_adam_]

Great video as always, id like to politely point out though that you have It and Iz the wrong way round.. Iz is the figure you get after applying factors. It is the current carrying capacity of the cable you select from the table in BS7671 hence the term “tabulated” as it comes from a table.

[@JPElectric]

Hi Ja_adam. Thanks for the comment My understanding is.. Iz is the current carrying Capacity for the cable for continuous service. It is the value we get, which must be ≥ the value we get by dividing the In or Ib by the relevant correction factors.

[@JPElectric]

Hi Ja_adam Just to clarify my answer. You are correct. The values we look up in BS7671 is the It - the tabulated value. I am doing another video which I hope will make this point clear. Thanks

[@avantgarde70]

This is great.

[@JPElectric]

Thank you avantgarde70

[@icetin9235]

great explain thanks can you do about EICR VIDEOES WHAT WE LOOK FOR Many Thanks

[@JPElectric]

Thank you , Yes would like to do an EICR video. Massive subject though. Will think on it.