Optimal PV Panel String Connection: Inverter & Panel Parameters for 210-480V MPPT Voltage Range

Choose the string length so the panels’ operating voltage under load is close to the inverter’s suggested/nominal PV voltage, but never let the string’s open-circuit voltage exceed the inverter’s maximum DC input voltage, especially in cold weather [#16278841] MPPT will track the best power point within its range, so you do not need to hit exactly 360 V, but you should keep the string in the MPPT window and near the inverter’s preferred working point for best efficiency [#16278841][#16279548] The voltage you calculate from Voc alone is not the full answer: use the panel voltage under load for the string size, then check that the total current of all parallel strings stays below the inverter’s max DC input current [#16278841][#16278519] As a practical rule, the thread advises leaving a few percent margin below the maximum voltage because a sunny, frosty day can push panel Voc above the nominal value [#16278841] The number of parallel strings is then limited by the inverter’s input current, and the total PV power should generally stay within about 115–120% of inverter power [#16278841]