Grounding solar panel array question

[Toddburkett]

I’m building a 24 panels (250 watt) 12‘ x 40‘ long pressure-treated wooden ground frame, if my panels aren’t touching each other do I need to ground the panels ? If I’m going to do that I’d have to link each of the panels together by the aluminum frames my question is is that necessary ? It’ll be two strands of 230 volts to the do you see combiner box with fuses and stuff, and then to the MPP controller which in turn will be connected to 100 amp panel that will be grounded in the traditional way with a rod in the ground . Is that sufficient?

 

[FilterGuy]

The NEC requires the frames to be grounded so yes, you should ground the frames.

Grounding Made simpler - Part 3: Solar Panels

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

12‘ x 40‘ long pressure-treated wooden ground frame,

Presumably, the wooden ground frame is some distance from the main building. In my opinion, the grounding of the frames should be routed back to the main building and tied into the earth grounding that is at the main building. I *think* this is also an NEC requirement. Others feel it is sufficient to do local ground rods for the PV frame grounding. Local ground rods are certainly allowed by the NEC but I don't believe this is required by the NEC. However, some local jurisdictions consider the PV Ground mount as a structure that must have it's own earth grounding electrode system.

 

[12VoltInstalls]

the grounding of the frames should be routed back to the main building and tied into the earth grounding that is at the main building

Filterguy: you’ve got my ocd tangled LOL
You debunked and rebunked panel mount grounding!
Any licensed electricians reading who can confirm this? I’m not arguing, I just want to know.

I’ve not advised this (I’m not a electrician nor an EE) because I was told by a local ME years back that because a panel mount is DC and shouldn’t be tied to the service earth ground, plus it can minimize lightning into a building.

I just want to know if that is correct; I mean it sounded good to me at the time.

 

[FilterGuy]

Filterguy: you’ve got my ocd tangled LOL

yea.... when it comes to grounding there are things NEC allows and things NEC requires. However, it is sometimes hard to sort out what is what because of 1) the number of places where the rules are different based on subtle differences in the particular situation and 2) the NEC is written in a way that makes it difficult to find the differences let alone understand them. On top of that, the NEC requirements on solar have been changing significantly on each new release so, about the time you think you understand it, it changes on you.

Once you have the NEC understood.... it can then all be changed by your local inspector. This is sometimes due to changes in code the local jurisdiction has made. However, it is often because the local inspector does not understand the NEC, and fighting their proclamation is almost impossible. Worse yet, if you fight and win, they will be pissed and take it out on you the next time they inspect one of your jobs.

 

[Supervstech]

I am an unlimited, licensed electrician.
The panels must ALL be tied together with a bonding system, and two ground rods installed at the array would be sufficient.
Some equipment install instructions require a grounding conductor of sufficient size to safely direct fault current be run with the power conductors to the indoor panel, or inverter.

 

[MurphyGuy]

The panels need to all be connected together, then sink a ground rod in at the solar array.. ground the panels to that ground rod and then connect that ground to your home's main panel ground as well as any inverters.

 

[MurphyGuy]

I am an unlimited, licensed electrician.
The panels must ALL be tied together with a bonding system, and two ground rods installed at the array would be sufficient.
Some equipment install instructions require a grounding conductor of sufficient size to safely direct fault current be run with the power conductors to the indoor panel, or inverter.

Darn, you beat me to it.

 

[12VoltInstalls]

The panels must ALL be tied together with a bonding system, and two ground rods installed at the array would be sufficient.

Thank you.

 

[Toddburkett]

I watched will talking about some grounding clamps that you gently hammer on to each panel kind of like little alligator clips? joining one panel to the next panel down to the end the last two adjoining to each other than to a grounding Rod I thought about it yet I don’t know where to order those any ideas?

 

[Supervstech]

I watched will talking about some grounding clamps that you gently hammer on to each panel kind of like little alligator clips? joining one panel to the next panel down to the end the last two adjoining to each other than to a grounding Rod I thought about it yet I don’t know where to order those any ideas?

That may work with a steel ground mount, and a clamp system designed around it. But it would need to be an approved mounting grounding system.
If it is a wood structure, ground rods would be required.

 

[JoeHam]

Here are some inexpensive WEEB style clamps :

https://www.amazon.com/gp/product/B07JPZYP4Q/

Or you could mount a rail like this on your wood structure. It has integrated bonding for your individual panels :

Tamarack Solar 89204 84" 4 Module Kit 1.6 Inch Rail Flush Mount Black Finish

Note: This unit is being phased out, limited supply available.

www.solar-electric.com

Add one ground wire at the end and your done. I just had a small self install pass code inspection with the Tamarac rail mounted on a wood shed roof with a single ground wire which was tied to the AC panel ground rod.