I'm trying to figure out the right cable size for my solar panel system. I have a total of 16 panels, each rated at 300 watts. I'm planning to connect 2 sets of 8 panels in series, and then parallel those two sets. The run from the panels to my charge controller is 30 feet. Would a 10 gauge aluminum MC4 cable work well for this setup, or should I consider something different?
2 Answers
For a 30-foot run, a 10 gauge cable would have about a 300mV voltage drop, which isn’t too bad. It’s rated for about 30 amps for continuous current. Since you’re getting 10 amps from a single panel, if you combine two in parallel, you’ll hit a theoretical max of 20 amps. Just make sure you check your panel's open-circuit voltage and system voltage too! What are they by the way?
You should look at the data sheets for your panels to figure out the maximum voltage and short-circuit current. A 10 gauge wire can handle 30 amps if it’s copper. If you’re using aluminum though, keep an eye on the specs to ensure you're safe with those current levels!