Those of you doing permits, are they asking for separate panel ground wire or through ground mount racking?

[hwy17]

I am doing no permits but I want my array to look legit.

Are inspectors requiring separate 6 awg bare or other ground wire ran from panel to panel, or does your ground mount system count as inherently bonded by the clamps and you run one ground wire to the frame of it?

 

[millsan1]

Ground mount should be OK, but you need to attach that to the main ground, using 6 AWG "where subject to damage", so anywhere outside a conduit.

That being said, I connected my ground mounts with the 6 AWG wire, as well as their physical binding. For a couple bucks more, makes me feel good. Totally not needed, but w/e.

 

[hwy17]

Ground mount should be OK, but you need to attach that to the main ground, using 6 AWG "where subject to damage", so anywhere outside a conduit.

That being said, I connected my ground mounts with the 6 AWG wire, as well as their physical binding. For a couple bucks more, makes me feel good. Totally not needed, but w/e.

But you didn't go panel to panel frame with the #6 right? Just across the ground mounts? I will bond my two bright mounts, and maybe consider doing that with continuous #6 back to the junction box, rather than a jumper.

 

[Zwy]

But you didn't go panel to panel frame with the #6 right? Just across the ground mounts? I will bond my two bright mounts, and maybe consider doing that with continuous #6 back to the junction box, rather than a jumper.

As I said in a video once about array grounding, "Some people spend their money on $8 coffee, I spend mine on copper wire."

I installed a lug on each panel frame and #6 copper wire runs to each lug in a big loop. I know I have a good connection that will last. All panels bonded.

 

[millsan1]

But you didn't go panel to panel frame with the #6 right? Just across the ground mounts? I will bond my two bright mounts, and maybe consider doing that with continuous #6 back to the junction box, rather than a jumper.

I went 6 AWG, between the ground mounts and back to PV disconnect, which then homes to inverter. I did go to the far end of the ground mounts, and put one lug on each portion of the ground mounts, so 2 lugs.

 

[millsan1]

As I said in a video once about array grounding, "Some people spend their money on $8 coffee, I spend mine on copper wire."

I installed a lug on each panel frame and #6 copper wire runs to each lug in a big loop. I know I have a good connection that will last. All panels bonded.

I did this on my roof mount, at least around the entire perimeter. Total of 18 panels, all bonded, but the 6 AWG runs around and bonds to 14 of the panels as some extra insurance.

 

[SunDave]

I'm thinking it depends if your mounting system is designed for grounding. The inspector didn't have a problem with the ironridge mounts being the ground once I showed him the clamping screws and that it was designed for it. Then I tied the "actual" ground to the iron-ridge rails with the ground lug. After the iron ridge rails, it is a custom mount.

 

[doksinc]

I think if clamping screws of ground mount are piercing (IronRidge) then panels are bonded together and then you simply drive ground rod and bond with clamp at one end. My ground mount uses piercing shims under the camps to bond each panel, then I drove a 8' ground rod at one end with clamp to ground wire.

 

[hwy17]

I think if clamping screws of ground mount are piercing (IronRidge) then panels are bonded together and then you simply drive ground rod and bond with clamp at one end. My ground mount uses piercing shims under the camps to bond each panel, then I drove a 8' ground rod at one end with clamp to ground wire.

I will not be intentionally grounding my array to a rod. Although the concrete posts with rebar might provide some unintentional grounding.

We won't get too far into this debate here. But just to explain that a bit more, the NEC now allows you to have an extra ground rod at the array, in addition to grounding back to the main panel ground, but the community opinion is now against adding the additional ground rod at the array. Mike holt also has some youtube videos covering his opinion, which aligns with the community.

 

[marionw]

690.43Equipment Grounding and Bonding.
Exposed noncurrent-carrying metal parts of PV module frames, electrical equipment, and conductor enclosures of PV systems shall be grounded in accordance with 250.134 or 250.136(A), regardless of voltage. Equipment grounding conductors and devices shall comply with 690.43(A) through (C).

(A)Photovoltaic Module Mounting Systems and Devices. Devices and systems used for mounting PV modules that are also used for bonding module frames shall be listed, labeled, and identified for bonding PV modules. Devices that mount adjacent PV modules shall be permitted to bond adjacent PV modules.

 

[hwy17]

690.43Equipment Grounding and Bonding.
Exposed noncurrent-carrying metal parts of PV module frames, electrical equipment, and conductor enclosures of PV systems shall be grounded in accordance with 250.134 or 250.136(A), regardless of voltage. Equipment grounding conductors and devices shall comply with 690.43(A) through (C).

(A)Photovoltaic Module Mounting Systems and Devices. Devices and systems used for mounting PV modules that are also used for bonding module frames shall be listed, labeled, and identified for bonding PV modules. Devices that mount adjacent PV modules shall be permitted to bond adjacent PV modules.

Thank you. I don't think the Brightmount really counts as listed, but as long as other mounting systems do then it shouldn't look out of place. The brightmount does have some piercing washers for the purpose of bonding the parts.

 

[Cmiller]

Thank you. I don't think the Brightmount really counts as listed, but as long as other mounting systems do then it shouldn't look out of place. The brightmount does have some piercing washers for the purpose of bonding the parts.

As long as the mounting system has piercing washers or clamps that are intended to make the ground connection, you only "need" (are required when inspected) to have one point of connection where the ground wire connects to the rails, or racking somehow. Technically it could go to one panel frame, as long as the racking system makes a ground connection panel to panel.

In regards to a ground rod at the ground mount, around here (northeast Ohio) most AHJs require standard grounding AT THE ARRAY. (2 ground rods, minimum 6 ft apart) In my personal opinion, when/if you have multiple pipes, 3 inches or bigger going a few feet into the ground (we usually go 3-5ft deep!) you have way more contact area to the ground than 2 measly ground rods will have, and you should be fully grounded! So it's kind of a redundancy, really. But at the end of the day, if it's inspected, you have to do what the AHJ asks for.

 

[Zwy]

If AHJ required it here for inspection, it would be disconnected as soon as I didn't see the tail lights. And the rod removed.

Just because an AHJ "requires" an auxiliary ground rod/s at an array doesn't mean it is a good idea. It is allowed under NEC but not required. That is an important distinction, as Mike Holt discusses in his videos the auxiliary ground electrode does nothing but expose a system to a voltage gradient if lightning was to strike nearby.

 

[Cmiller]

If AHJ required it here for inspection, it would be disconnected as soon as I didn't see the tail lights. And the rod removed.

Just because an AHJ "requires" an auxiliary ground rod/s at an array doesn't mean it is a good idea. It is allowed under NEC but not required. That is an important distinction,

I agree with you. And also, over the years there have been plenty of things that have changed in the code book because of evidence over time that something isn't best practice. For instance, outlets serving an island and bar no longer being allowed to be on the side where the cord can cause an item to fall off the edge. Now that one is also one of those cases where you could possible put an outlet there that was "not to serve the island or bar", only just an additional outlet..... You can always add outlets where you want/need them, but code doesn't require them (such as high on the wall for a garage door opener, for instance).... whole 'nother can of worms there.

as Mike Holt discusses in his videos the auxiliary ground electrode does nothing but expose a system to a voltage gradient if lightning was to strike nearby.

So, regarding that, I would say that I don't know if you would gain anything by removing the rod(s) if the mounting system is metal posts going into the ground... I totally get the concern of this scenario, and I agree that it heightens that risk! But removing the rod(s) will only help minimally, the way it looks to me. Which then brings up the question, is there any way to get around this? Some kind of insulated brackets between poles/rack and the rails and panels..??

 

[Quattrohead]

So in my situation, the panels are around the left middle of the roof. The equipment is off to the right, my main house ground is here.
But, the run down to ground on the left is shorter so I feel it is a good idea to run a ground there too. Why ?
The whole slab is grounded via a UFER, my main ground is connected to this UFER and I can drive a ground rod on the other side of my slab that can service the panels 'better' There should not be much of a gradient across the system but I feel like I want induced voltage to be encouraged away from my equipment.
At the end of the day, Mother Nature will do as she pleases and we are all along for the ride.

 

[Cmiller]

At the end of the day, Mother Nature will do as she pleases and we are all along for the ride.

That's for sure! Midnite lightning arrestors are absolutely phenomenal when it comes to lightning strikes nearby! But if you have a direct strike, you simply can't do much but inspect the carnage afterwards, and get a game plan together for what needs to be repaired.