Build charging cable 3 phases 400V yourself, maximum power consumption T8?

In my configuration I could not see at the time where the time difference lies when charging. For me, the common house socket 16A and thus 3,7kw. So came to my blue-eyedness, with the specified 2.5 hours charging time. But now there is only a 10A cable (schuko) with… So there is a box in the cable ICCB (in cable control box), which communicates with the car, regulates charging current and measures error current. Super. If I load now on a public column, this column takes over the communication with the car. So an ICCB is not required. Also great. 1. What would happen without the ICCB to a Schukodose? Nothing at all? 2. What do I have to do for ICCB if I have a 3PH CEE can installed? 3. Is the box always necessary? Whether in the wallbox, column or in the cable? Without a box, no charging process?