I'm planning to install a pair of 14mm² aluminum wires, which are rated for 600Vac and designed for mains service drops, instead of using the traditional 10mm² PV wires rated for 1000Vdc for my solar panel setup. I want to understand if there are significant differences or potential drawbacks to this choice. The maximum open circuit DC voltage I anticipate from the solar panels is 450Vdc. I'm also installing 600V DC surge protective devices on both ends of the wires. The solar panels will be mounted on the garage roof, about 50 meters away from the main house, with a maximum current of 13.5A and a total power output of 5.31kWp.
2 Answers
Just a quick note: solar cables usually come with double insulation, which can be a requirement based on where you live. Make sure to check local codes to ensure you're compliant!
Price is definitely a major factor here. Switching to 14mm² aluminum instead of the 10mm² PV wire can save you quite a bit of cash. In my own setup, I've used multiple runs of 10 AWG wire over 400 feet and experienced power losses of under 1%. So in practice, you should be fine using the 14mm² option!
True, but don't forget that 14mm² or #6 AWG wire is nearly 50% cheaper than the 10mm² PV wire, so you'll save quite a bit.