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Regulation stating a type AC RCD can not be upstream from a type A RCD

Alan B

Hi

I found an EV charger today with built in type A RCD + RDC-DD connected to a type AC RCD in the consumer unit, the AC RCD is also protecting 3 other circuits including sockets. I know this is incorrect because the type AC RCD could be blinded by DC currents, but I am struggling to find a regulation to reference when providing information to the customer?

Thanks

Alan

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    If you decide that a circuit or particular appliance needs a RCD that can deal with DC leakage and then leave an existing AC RCD that is required for a different purpose upstream then you may have well rendered that upstream RCD inoperable, so effectively you might as well have taken it out and thrown it over a hedge.

    Likewise if you need a RCD that needs to deal with DC leakage and fit or leave a Type AC RCD you cannot be certain it will work, even after testing.

    I presume the point being made in Codebreakers is if you need a RCD, it has to be suitable and fit for purpose, otherwise it’s useless.

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  • 0

    If you decide that a circuit or particular appliance needs a RCD that can deal with DC leakage and then leave an existing AC RCD that is required for a different purpose upstream then you may have well rendered that upstream RCD inoperable, so effectively you might as well have taken it out and thrown it over a hedge.

    Likewise if you need a RCD that needs to deal with DC leakage and fit or leave a Type AC RCD you cannot be certain it will work, even after testing.

    I presume the point being made in Codebreakers is if you need a RCD, it has to be suitable and fit for purpose, otherwise it’s useless.

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