I've just had an EV charger installed, and taken the opertunity to have my old fuse box replaced with a new consumer unit, and the garage properly wired with a submain. The house is TN and the garage now TT. The SWA is sourced from an MCB. I've realised that there's one unlikely but very nasty fault that isn't well protected against. If the SWA live tail, coming into the garage CU, somehow made contact with the body of the CU, there wouldn't be enough current through the earth rod to trip the MCB at the house and the fault is the wrong side of the RCBOs in the garage. The body of the car, if plugged in, would go live. Any thoughts on this?
