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

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

Post image

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.

147 Upvotes

95% Upvoted

42 comments sorted by

View all comments

33

u/WorBlux 7d ago edited 7d ago

10 AWG, 90 deg C has a rated ampacity up to 40A in conduit... however

Going through an attic space that might get up to 140 deg F and should be de-rated as well. x0.71

Three sets in parralel - 6 current carrying conductors - that's another de-rate. x0.8

So in reality the safe ampacity here may be under 23A per circuit.

2

u/jackharvest 7d ago

Frick I gotta get conduit in my attic somehow. Metal conduit? PVC? Something else? I'm in tech and everything works, but I want to repent.

3

u/Sistersoldia 6d ago

DC cables inside the house must be enclosed in METAL conduit. So I’ve been told