The following tables focus on stand-alone PV systems where the PV array power is directed to a MPPT charger. Currents are limited to 30 A which is a typical maximum value accepted at the input of commercial power chargers up to 7 kW . The left column provides the current while in the horizontal direction the quotient of the length of the single path of the conductor over the operating voltage (in m / Volt) of the PV array (the circuit consists of conductors of total length 2L) is listed.
The calculations refer to conductors made of copper and for a voltage drop of 2% . The cross sections are given in square millimeters (mm ^ 2) and therefore we choose the next largest cross section that is (commercially) available ( 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35 , 50, 70, 95, 120, ….).
At the bottom of the page is a table with indicative values of the maximum allowable current per section of the pipeline.