Wiring and other considerations for solar installation
Fig. 1. Wire cross-sectional area in mm2
Before connecting the solar panel to the grid-tie inverter or the charge controller, the solar developer must decide what size of wire to use. These are the steps involved:
1) Get the power requirement (PW) of the device, solar panel, or load.
2) Get the current (A) requirement of the electricity path by dividing the power requirement PW by the voltage V that will run through it.
A = PW / V
If you already know the current passing through the wire in Amperes (A), go directly to step#3 below.
3) AWG#8 has 8mm2 of wire area and so can pass 32A of current. Start from there. For every mm2 of wire, less than 4A should run through it. If your current is less than 32A, go down the next wire category in Fig. 1 (AWG#10, 5.5×4=22A). If your current is more than 32A, go up the next wire category. Do this until your current is as close to the wire rating ampere capability
If your wire passed the condition in item#3, your wire is sized according to standards.
Let’s take an example. A 250Watt solar panel passes a maximum 8.5A. AWG#14 is too close and AWG#10 is a bit oversized. AWG#12 is just right and can pass 14A (3.5X4).
AWG#10 and AWG#12 are the most common wire sizes used for solar panel installations and household wiring for lights and typical appliances.
Wiring is just one of the many considerations involved in solar power system installations. If you want to learn more, attend our solar seminar held every end of the month.
For more details, visit our facebook page or check this page out.