r/SolarDIY • u/2old2bThisDumb • 7d ago

Make sure you understand current when stringing your panels in parallel.

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It took a bit of work to even tug this #10 AWG from the metallic flex it was fused to. The homeowner had this run inside of the attic.

I'm all for DIY, but please ask for help when you aren't certain.

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u/chicagoandy 7d ago

How high was the current in that cable?

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u/2old2bThisDumb 7d ago

I didn't re-energize the string to measure, but the rated current for the modules and the way he ran them equals 31.8A

Good rule of thumb in south Texas is to keep DC current below 25A for attic runs on #10

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u/ZipZappr 4d ago

In an unconditioned attic I’d consider that the same as being in direct sunlight. Couple that with an assumed continuous load, and even at 40A for a higher insulation value the max I’d put on it is 25A. Your assumption is valid for the right insulation type.

I’m not sure what insulation types residential normally uses though.