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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. 


Parents
  • 0
    There is no issue having an MCB in the consumer unit feeding an RCD in a box (or even an RCBO in a box), as an alternative when you do not have a suitable RCBO.

    But the section of cable between them that is not RCD protected and so needs to be either surface wired, so visible ,or armoured if hidden or protected to an equivalent degree (metal trunking / steel conduit or whatever.) Obviously the cable needs to have current rating to  match or exceed the MCB ....


    If it has to go far then a length of SWA is often the easy 'route anywhere'  way.


    Also be aware that some EV charger designs require a type B RCD that detects DC faults- not to be confused with a type B MCB.

    You may like to sit down before checking the price of those, and then make sure to buy a charger that does not require this.


    Then there is the as yet unraised issue of earthing the charger and how your house is earthed. If the care is outside to charge, you may need to make the charger a TT island, and if the house is PME that means keeping it away from anything that may be earthed to the house earth.

    M.
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  • 0
    There is no issue having an MCB in the consumer unit feeding an RCD in a box (or even an RCBO in a box), as an alternative when you do not have a suitable RCBO.

    But the section of cable between them that is not RCD protected and so needs to be either surface wired, so visible ,or armoured if hidden or protected to an equivalent degree (metal trunking / steel conduit or whatever.) Obviously the cable needs to have current rating to  match or exceed the MCB ....


    If it has to go far then a length of SWA is often the easy 'route anywhere'  way.


    Also be aware that some EV charger designs require a type B RCD that detects DC faults- not to be confused with a type B MCB.

    You may like to sit down before checking the price of those, and then make sure to buy a charger that does not require this.


    Then there is the as yet unraised issue of earthing the charger and how your house is earthed. If the care is outside to charge, you may need to make the charger a TT island, and if the house is PME that means keeping it away from anything that may be earthed to the house earth.

    M.
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