I'm working on installing wiring for my solar panels—specifically, I've got 6 wires (three strings of 10 AWG) coming from 24 solar panels that I need to run to my inverter from the roof. Can I legally fit all 6 of these wires into a 1" EMT? Also, do I have to start using the EMT as soon as the wires exit the roof, or can I run them without EMT until they enter the building?
4 Answers
It's definitely doable as long as your pulls aren't too crazy. Just keep in mind that PV wire has thicker insulation compared to standard wire. Make sure you’ve got a solid ground to go along with those wires!
You might want to consider switching to THHN wire for easier pulling through a junction box. Using THHN can make things a lot easier, and you can fit three strings in 3/4" EMT. Just a thought!
For your situation, using an online conduit calculator can really help make sure you're compliant. Also, don't forget to include your ground wire! That seventh wire is super important and should be in that conduit too.
I can't quote the exact regulations, but I think you'll be fine with six wires in one-inch EMT. Personally, I used 1.5" for my three strings, and it felt like overkill! More room for movement!