But truly optimizing the string's output means choosing a string length that lands within a more narrow optimal voltage range: the “rated MPP (maximum power point) voltage range. When the length of the cable is long for a certain current flow and wire size, the electrical voltage that will reach the load, whether it is charge controller or inverters, will be less, and the device may not work to charge the batteries properly, as the charge controller is not designed to. This tool determines the maximum string length for a solar PV installation in a particular location. The method is in accordance with National Electric Code (NEC) 690. We would highly appreciate any feedback (praise, bug reports, suggestions, etc. Please contact us at. Selecting the appropriate length of DC solar cables requires a balance between minimizing energy losses, adhering to safety standards, and optimizing installation costs. In this guide, I'll walk you through how to use an online calculator that will give an estimate of line losses, and compare. By.
