Solar wire help please

[gaza2015]

Help please I've got 4 x 400 watt panels wiring in series volts go up amps stop as thay am running the wire 20 feet away which wire would I need to do that thanks would 10mm2 do it

 

[shvm]

4 x 400 watt panels wiring in series

most 400 wp class panels ship with MC4 connectors and 4 sq.mm wires from factory.


10 sq.mm is probably overkill.
You should be fine with 6 sqmm wire even accounting for long distance runs.