The question is connecting the garage CU to the house CU? In the 17th editi on wiki article the CU arrangement for a fully RCBO populated CU shows an M CB being used for the garage using SWA. In my case that will not be possibl e as the cable between CUs will be T&E with approx. 2m run in a wall chase. Is there any reason why the garage circuit cannot be protected by an RCBO at the house CU even though there will be further RCBOs for the separate ga rage/Mancave circuits?