The sizing of the wire is very important for any solar power system. The over-sizing can increase the overall cost while under sizing can lead to the burning of the wires. The heat generated in the wires is directly proportional to the square of the current flowing in them, meaning higher is the current more it will heat the wires and we need thick wires to keep the wires cool.
Heat 𝞪 (Current)²
The 5 kW system specifications
Let me assume that I will be using 200 Watts panels to design my solar power system. So, for that purpose, I am going to use 5000/200 = 25 solar panels in total for designing the system.
The Electrical Characteristics of the 200-Watt/ 12-volt solar panel is as follows:
The optimum system voltage for the 5 KW system is 60 Volts. Therefore, I need to connect 5 strings of solar panels in parallel and each string has 5 solar panels (200 Watts/12 volts) in series in order to make the system voltage of 60 volts.
Before going ahead, we should know the certain variables to know the diameter of the wire and these are as follows:
Putting all these values in the formula given below:
Diameter of the wire is 1.56 mm or 13-gauge wire should be used for the connecting the solar panels with the inverter.
In the parallel combination, the current adds up while the voltage across the strings remains the same whereas in the series combination the voltage adds up and the current flowing in the series remains the same.