The bonding is sized according to the supply neutral conductor on a PME system and sized according to the earthing conductor on a TN-S. It should not be less than 6mm in any case. If you have a PME set up you can generally let 6mm go as long as there are no signs of corrosion or thermal issues surrounding the connection. If it is PME just add a c3 and state 'undersized but no adverse conditions found to cable on inspection'.
Best EV Chargers by Electrical2Go! The official electric vehicle charger supplier.
OFFICIAL SPONSORS
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc