Superstrut/Unistrut grounding individual panels

[Bluedog225]

Good morning,

I’ve get a headache looking at mounting options. I’m pretty sure I’m going with super strut based on cost availability.

I’ll be mounting 4 rows of 8 panels on a flat metal standing seam metal roof with S5! connectors, strut, and fittings with bolts/washers.

My research indicates that individual grounding of each panel is best. I’ve got two questions.

1. What is the best (pay once/cry once) connector between the grounding wire and the panel? Is it a copper lay in lug with a stainless screw? (Available at home depot) or something more specialized or galvanized?

2. How do I calculate the size of the grounding wire assuming a 12.8 kw system with IQ8 micros? Is it 3200 watts per string divided by 120 volts equals 35 amps? And a 4x larger wire to ground? That can’t be right. My panel count may change and I’m interested in understanding the calculation. I’d like to do a professional job on this install.

Many thanks!

 

[rmaddy]

This may be useful:

Grounding Made simpler - Part 2: Stationary Systems

To get the paper, click on the orange button at the top of the screen. The subject of grounding is a complex, multifaceted subject, that is often treated as an after-thought but needs to be considered from the beginning of the design and build...

diysolarforum.com

 

[Bluedog225]

Great. Will read. Thanks!

 

[Bluedog225]

Wow. What a great resource. Just what I needed. Thanks again!

And many thanks to the author.