Solar carport grounding

[-robw-]

Hi, question. Carport sits on 18" of agricultural dirt, with varying layers of hard and soft caliche beneath. It is supported by 18 4ft rebar anchors and 6 4ft trailer anchors. My panels are secured to unistrut with steel bolts and square washers, and that unistut is bolted directly to carport tin roof. So, steel to steel to steel. Although no anchor is 8ft in ground it does seem to me that my panels are sufficiently grounded. Would I be wrong?

Note: an 8ft ground rod will still be set for chassis grounds.

[SunEagle]

While a mechanical steel bolt system between the metal roof and panel racks could be considered an "unbroken" ground path they could loosen up over time and no longer create a true "ground path" for the panel frames.

To be safe some type of ground conductor system should be added between the panel racking and that ground rod.

[khanh dam]

steel will rust. especially in area where steel parts make physical contact and water tends to collect.

[emartin00]

Given the number of anchors, your structure will probably be adequately grounded, but without the proper equipment, it's impossible to tell for sure. If you're adding a ground rod for "chassis ground" just tie it into the structure.
As khanh mentioned, unless you are using hot dip galvanized, or stainless hardware, they are going to rust quickly. You will also need some method of grounding the aluminum frames of the solar modules to the structure. I would suggest WEEBs.
Also, is the roof galvanized metal, or painted? If it is painted metal, you may not have a good bonding connection there either.

[-robw-]

Thanks for the responses. With them, I'm at it's ok for now but in the future I should upgrade panel grounding. It's just I was surprised by the number of anchors the installers used and thought I may be able to get away with returning 100ft of grounding wire and lugs. I'll hold on to them instead.

Help with search: I have 16 6 volters that have been sitting for at least one month. Is there a sticky on how to treat them prior to system integration? Should I fully charge them individually first?

[SunEagle]

Thanks for the responses. With them, I'm at it's ok for now but in the future I should upgrade panel grounding. It's just I was surprised by the number of anchors the installers used and thought I may be able to get away with returning 100ft of grounding wire and lugs. I'll hold on to them instead.

Help with search: I have 16 6 volters that have been sitting for at least one month. Is there a sticky on how to treat them prior to system integration? Should I fully charge them individually first?

Depending on how you are going to wire those 16 x 6V batteries I would first make sure each is up to 100% SOC and then create your battery bank.

My concern is with that many batteries you are trying to create a bank with multiple parallel wired strings of batteries. With parallel strings you end up charging and discharging them unequally which will lead to one or more going to an early death and bringing down the entire bank.

[-robw-]

Depending on how you are going to wire those 16 x 6V batteries I would first make sure each is up to 100% SOC and then create your battery bank.

My concern is with that many batteries you are trying to create a bank with multiple parallel wired strings of batteries. With parallel strings you end up charging and discharging them unequally which will lead to one or more going to an early death and bringing down the entire bank.

2 strings, correct. Your answer is as I suspected, although I held hope on just needing to charge each string independently. Thanks for input.