"17 edition"consumer units still being sold.

Whilst what he says is correct, DC leakage is not a normal phenomenon in installations. We have discussed it in car charging at length because there it is possible due to the car communications system with the charger and a single fault, but it is probably not possible with other electronic loads which never leak DC because the design runs with AC! Asymetric AC and other things do not result in DC (and it needs to be pure and smooth) leakage.

I suspect problem is a bit wider than just AC type RCDs being blinded by pure d.c. Have a look at Figure A53.1 in the regs (page 192) - and then imagine a fault in an appliance from L after some of those diodes to the metallic case - especially on a TT system were we can't rely on the earth fault current being sufficient to trigger overcurrent protective devices or even blow the rectifier to smithereens. Then look at the right most column and note how quickly AC types disappear from the list of acceptable types.


    - Andy.

Whilst what he says is correct, DC leakage is not a normal phenomenon in installations. We have discussed it in car charging at length because there it is possible due to the car communications system with the charger and a single fault, but it is probably not possible with other electronic loads which never leak DC because the design runs with AC! Asymetric AC and other things do not result in DC (and it needs to be pure and smooth) leakage.

I suspect problem is a bit wider than just AC type RCDs being blinded by pure d.c. Have a look at Figure A53.1 in the regs (page 192) - and then imagine a fault in an appliance from L after some of those diodes to the metallic case - especially on a TT system were we can't rely on the earth fault current being sufficient to trigger overcurrent protective devices or even blow the rectifier to smithereens. Then look at the right most column and note how quickly AC types disappear from the list of acceptable types.


    - Andy.