With “AC connection”, I mean the AC cord and the AC socket in the car.
The AC cord has a conventional “Type F” male plug (CEE 7/4) towards the wall socket, and a female “Type C” CEE 7/16 plug towards the car.
The cord is equipped with a protection device SPE-PRCD (Switched Protective Earth - Portable Residual Current Device), as defined in DIN IEC 62335 (VDE 0661-20) - mostly however referred to as “PRCD-S”. As the name suggests and in contrast to a conventional residual current circuit breaker installed within the car, a SPE-PRCD is capable of interrupting (resp. not connecting) all connections including protective earth in case a fault is detected.
This is essential when connecting to a wall socket with faulty ground connection. Leakage current from other wall sockets may easily cause hazardous voltage on the wall socket's ground connection. Without SPE-PRCD, the car chassis would also convey this voltage. If someone happened to have contact to both the car chassis and ground, a conventional residual current circuit breaker installed in the car would not register the resulting current. Depending on the kind of the fault, some other protection switch somewhere around might finally trip, but this of course cannot be relied on.
To have a reliable fault protection within your own area of responsibility is a major advantage of the SPE-PRCD, and outweighs its obvious drawbacks - the device is bulky, expensive, exposed to damage and theft, and it requires to push a “start” button every time it is powered up.
Please note that embarassingly, the depicted device turned out to only be a lousy “RCD” protection switch, with ground permanently connected through! I had let myself be fooled by the name “personal protection switch”, which however is not clear enough. So, when purchasing such a switch, it is mandatory make sure that it is “SPE-PRCD” or (more likely) “PRCD-S”!
The male CEE 7/16 socket is installed behind the tank lid. With an additional rubber muffle and some glue, the socket (actually a plug) could be fitted into the gasoline nozzle.
As to provide feed-back whether the cable is connected or not, an electromagnetic proximity sensor is also installed next to the tank lid. It required to weld up an individual mounting bracket (see also immobilizer relay)
The tank lid turned out to be made of plastic, so I glued a washer to its inner surface to make it visible to the sensor.
Now, where have I seen that picture before?!