Use this CT clamp with a solis inverter to limit export to the grid. G100 compliant.
The cable supplied is 10M of 0.2mm2 with 300v insulation
If you want to extend with another 40m of cable (total 50m) use – 2c 0.5mm^2 with 300v insulation.
Ideally shielded cable and not in AC conduit. ie. CAT6