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EV Charger Questions

vantech
Hi,


I am planning on installing an EV charger for my own home and have 2 questions. 


1) Can an RCBO with a B curve be used for EV chargers, as I am seeing a mixture of "C" and "B" between different manufacturers - I have called Pod Point who are worryingly unable to give this information. As MK have apparently stopped with some of their switch gear business, I am struggling to find a C curve type A RCBO at 40 amp but can find plenty of B curves (hence this question). 

2) If I need a C curve, I have an issue in that the current CU only has 2 spare ways (bad design by the previous installer!) and I cannot install another DB as this would look very ugly, therefore to avoid mixing manufacturers inside of the consumer unit, could I have a C40 feed a separate enclosure that contains an RCCB rated at 100amp, with an A characteristic - therefore the MCB would feed the RCCB which would then feed the EV charger - generally the RCCB goes before the MCB, but wanted to check there wasn’t a non-compliance to 7671 as a result of doing this?


Thanks. 


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  • 0
    John Peckham:

    You need either a Type B double pole 30mA RCD or Type A with DC protection.


    The RCD has to comply with BS EN 61008 or BS EN 61009. You cannot have compliance with those standards on a PCB.


    BS 7671 722 lists a number of BSs and BS ENs that the charging installations have to comply with. Ask you charge point manufacturer for a Declaration of Conformity indicating their equipment complies with those requirements. Also the equipment or the packaging has to be CE or UKCA or UKNI marked.


    I went to the NICEIC for their view. I havent included my question but it is rather obviously based on JP's post. 
    Hello Lyle,


    Thank you for your enquiry,


     


    Regulation 722.531.3.101 of BS 7671: 2018 amended 2020, requires that unless the protective measure of electrical separation is used, each charging point shall be protected by a 30mA Residual Current Device. Within the same Regulation it states that the RCD shall comply with one of the following British Standards; BS EN 61008-1, BS EN 61009-1, BS EN 60947-2 or BS EN 62423.


     


    There is some debate as to whether the RCD components installed within some manufacturers’ charging equipment comply with the above requirements.


     


    At this moment in time Note 5 of Regulation 722.411.4.1 places the emphasis of ensuring compliance squarely on the shoulders of the electrical designer/installer, as can be seen in the Note below;


     


    60e40dbace282a1444faf8909bbfeabd-original-image-20210520102304-1.png

     


    We would therefore agree with your suggestion of the installation of a recognised Residual Current Device upstream of the charging point, where any doubt exists. With regards to the issue of a lack of selectivity, so long as this does not cause a dangerous situation to occur, it would be acceptable. As the two RCDs are in series on a dedicated circuit, it would be difficult to envisage a dangerous situation, however as the installer this would be a decision that you would have to be satisfied with.



     
Reply
  • 0
    John Peckham:

    You need either a Type B double pole 30mA RCD or Type A with DC protection.


    The RCD has to comply with BS EN 61008 or BS EN 61009. You cannot have compliance with those standards on a PCB.


    BS 7671 722 lists a number of BSs and BS ENs that the charging installations have to comply with. Ask you charge point manufacturer for a Declaration of Conformity indicating their equipment complies with those requirements. Also the equipment or the packaging has to be CE or UKCA or UKNI marked.


    I went to the NICEIC for their view. I havent included my question but it is rather obviously based on JP's post. 
    Hello Lyle,


    Thank you for your enquiry,


     


    Regulation 722.531.3.101 of BS 7671: 2018 amended 2020, requires that unless the protective measure of electrical separation is used, each charging point shall be protected by a 30mA Residual Current Device. Within the same Regulation it states that the RCD shall comply with one of the following British Standards; BS EN 61008-1, BS EN 61009-1, BS EN 60947-2 or BS EN 62423.


     


    There is some debate as to whether the RCD components installed within some manufacturers’ charging equipment comply with the above requirements.


     


    At this moment in time Note 5 of Regulation 722.411.4.1 places the emphasis of ensuring compliance squarely on the shoulders of the electrical designer/installer, as can be seen in the Note below;


     


    60e40dbace282a1444faf8909bbfeabd-original-image-20210520102304-1.png

     


    We would therefore agree with your suggestion of the installation of a recognised Residual Current Device upstream of the charging point, where any doubt exists. With regards to the issue of a lack of selectivity, so long as this does not cause a dangerous situation to occur, it would be acceptable. As the two RCDs are in series on a dedicated circuit, it would be difficult to envisage a dangerous situation, however as the installer this would be a decision that you would have to be satisfied with.



     
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