Help please! I need a Tesla Gen 2 EV charger fitted in my garage which is 22m from the consumer unit. My electrician is proposing to route a 6mm cable through pre-existing plastic conduit which has a cable in already and through a void in concrete walls to a sub-consumer unit at the charge point. My very limited knowledge of electrics makes me worry that the cable is not big enough. Also can you site the sub-unit so far from the main consumer unit? The SPD and RCBO will be in that sub-box he says. Advice needed please