The system’s maximum operating voltage refers to the highest voltage at which your solar system array should operate. When connecting an inverter or controller to your array, this metric becomes essential. In simpler words, the maximum system voltage of your solar panels should be compatible with the capacity of your solar inverter or controller.
The system’s maximum operating voltage from solar panels can be detrimental, causing damage to the system and preventing it from functioning properly. This happens because the inverter is prone to failure or shutdown when the system voltage exceeds its maximum capacity.
How to Calculate Maximum PV System Voltage
The maximum voltage for a DC photovoltaic (PV) system is determined by adding the open-circuit voltage of the PV modules, adjusted for the coldest temperature expected. The correction factor is to be applied to the rated open-circuit voltage of both crystalline and multicrystalline silicon modules.
The voltage provided will serve as a crucial factor in establishing the voltage rating for cables, disconnects, overcurrent devices, and various other equipment. If the temperature is expected to be lower than -40°C (-40°F) or if PV modules made of materials other than crystalline or multi-crystalline silicon are used, follow the manufacturer’s instructions to adjust the system voltage.
Here is a table for correction factors for voltage in crystalline and multi-crystalline silicon modules.
|Ambient Temperature (°C)||Factor||Ambient Temperature (°F)|
|24 to 20||1.02||76 to 68|
|19 to 15||1.04||67 to 59|
|14 to 10||1.06||58 to 50|
|9 to 5||1.08||49 to 41|
|4 to 0||1.10||40 to 32|
|-1 to -5||1.12||31 to 23|
|-6 to -10||1.14||22 to 14|
|-11 to -15||1.16||13 to 5|
|-16 to -20||1.18||4 to -4|
|-21 to -25||1.20||-5 to -13|
|-26 to -30||1.21||-14 to -22|
|-31 to -35||1.23||-23 to -31|
|-36 to -40||1.25||-32 to -40|