Question about Thermaltake Toughpower GF3 PCIe 5.0 (1350W)

According to the manufacturer, the power supply has a C20 connection. This is not necessarily relevant for a Swiss socket; cables with a C20 connection can support up to 16A @230V, while most commercially available cables support a maximum of 10A. The 10A limit therefore comes from the cable and not from the fuse/connection, as a T13 connection usually runs on a 16A fuse (always check yourself how the sockets are fused, this varies from household to household, especially with older circuits only a 10A fuse may be installed). The power supply can therefore draw approx. 5.9A at 100% load at 230V (efficiency and other factors not taken into account). The power supply unit can therefore be plugged into a normal T13 socket with the appropriate cable.

The part is either defective or does not run on my T13 socket (modern household built in 2016) Digitec please clarify what is going on here. Steg on the website says "Please note that this power supply requires a 16 amp T23 socket and cannot be used with a normal T13 socket. A T23 socket requires a minimum of 2.5mm² in the 'house wiring'" If this is true it might be worth mentioning! In addition, you have supplied a normal power cable which does not even fit into the power supply unit!