Ah, we did the Two for the grade, and then pick a fav from previous gradings and perfect it.

The ground ... they show pictures of a big metal rod to be driven into the ground and connected up ! so definately an earth connection point.

As I said, as these are sold worldwide, I assumed it was for counties or area where the supply had no PE system ?

With a TN-S system in the workshop, I didn't want to add a local earth to the machine due to the resistance in the earth from the house/supply to the shop.
If I change to TT, then it's not a problem to double up, even if it doesn't seem necessary .