Do I have a big array grounding problem here?

[1201]

The whole system is connected to the main ground at the inverter.

But then I just realized that the panels are sitting on aluminum frames directly on the ground ,so its like having a ground rod.

Is this going to cause issues? Should I remove the ground at the inverter?

 

[McKravitts]

Definately don't remove the ground to the inverter.
Thre may be a way to connect an array ground to the house ground.
How far is the array from your houses ground rod?

 

[1201]

Definately don't remove the ground to the inverter.
Thre may be a way to connect an array ground to the house ground.
How far is the array from your houses ground rod?

the array ground is currently connected to the house ground. that's my question- is - is this dangerous? I know many advise not having an array ground but in this case I dont have a choice.

Edit. I should clarify that that Inverter ground is connected to the main house ground

 

[Drunkin Solar]

I know when we ground large commercial buildings most commonly many ground rods are driven at various points and all are connected with bare copper cable leading back to the main grounding bond. The purpose as I understand it is that a fault or lightning strike will dissipate voltage along it's length protecting from any one spot having large potential differences. I would think the same would apply to a solar array back to the main bonding point.

Is your grounding conductor insulated?

 

[Gavin Stone]

This is the case with most arrays unless they are built out of wood. The array itself is grounded. Although technically that isn’t considered to be a ground.

 

[RCinFLA]

If lightning strikes one of those trees behind array there can be several thousand volts of ground voltage gradient radiating out from base of tree that got hit. Actual earth ground has some resistance depending on soil composition and moisture.

Keep PV grounding wiring from PV frame and base outside of house and connected directly to house grounding stake. Although rare, it is possible the ground wiring from remote PV array can get vaporized from a direct lightning strike. If array is greater than about 50 feet away from house grounding stake there should be an additional ground stake below array.

You need good lightning surge protection on PV pos and neg lines to ground rod. The device that PV lines connect to has the largest risk of damage.

 

[marionw]

All exposed not-current carrying metal for the entire array is required to be grounded. You must ensure that the panel frames are properly grounded to the mounting system and that the mounting system is also grounded.

690.41 System Grounding
690.43 Equipment Grounding and Bonding
690.47 Grounding Electrode System

"Exposed non-current-carrying metal parts of PV module frames, electrical equipment, and conductor enclosures of PV systems shall be connected to an equipment grounding conductor in accordance with 250.134 or 250.136, regardless of voltage. Equipment grounding conductors and devices shall comply with 690.43(A) through (D)."

Some jurisdictions will permit grounding rods at the array and not require a ground carried back to the inverter/service entrance ground (usually near the meter) and some require the ground is carried back. Always depends on the inspector and his/her interpretation of the NEC and which version of the NEC has been adopted by the local jurisdiction. In most cases you can always have grounding rods installed at the array even though you also bring the ground back to the house.

 

[gotbeans]

Are those a bunch of chairs upside down?

If lightning strikes one of those trees behind array there can be several thousand volts of ground voltage gradient radiating out from base of tree that got hit. Actual earth ground has some resistance depending on soil composition and moisture.

Keep PV grounding wiring from PV frame and base outside of house and connected directly to house grounding stake. Although rare, it is possible the ground wiring from remote PV array can get vaporized from a direct lightning strike. If array is greater than about 50 feet away from house grounding stake there should be an additional ground stake below array.

You need good lightning surge protection on PV pos and neg lines to ground rod. The device that PV lines connect to has the largest risk of damage.

I don't think the lighting surge devices will protect against any direct hit on panels. I don't think that exists.
It's better to hope your wires vaporize and not reach the devices

never heard of the extra grounding stake, seems a lot of people here are against more stakes

 

[Drunkin Solar]

Using a bare grounding conductor (not inside conduit) from your array back to the bonding point is best practice from an electricians training standpoint. Ground rods at the array with metal pole mount can't hurt as it's already grounded.

 

[1201]

I know when we ground large commercial buildings most commonly many ground rods are driven at various points and all are connected with bare copper cable leading back to the main grounding bond. The purpose as I understand it is that a fault or lightning strike will dissipate voltage along it's length protecting from any one spot having large potential differences. I would think the same would apply to a solar array back to the main bonding point.

Is your grounding conductor insulated?

The grounding conductor is insulated, yes.

This is the case with most arrays unless they are built out of wood. The array itself is grounded. Although technically that isn’t considered to be a ground.

This is the answer! You're right a lot of these are out there. That put me at ease. Thanks.

If lightning strikes one of those trees behind array there can be several thousand volts of ground voltage gradient radiating out from base of tree that got hit. Actual earth ground has some resistance depending on soil composition and moisture.

Keep PV grounding wiring from PV frame and base outside of house and connected directly to house grounding stake. Although rare, it is possible the ground wiring from remote PV array can get vaporized from a direct lightning strike. If array is greater than about 50 feet away from house grounding stake there should be an additional ground stake below array.

You need good lightning surge protection on PV pos and neg lines to ground rod. The device that PV lines connect to has the largest risk of damage.

I currently have the grounding going to the inverter. That ground is connected to the house grounding stake via a 90ft ground wire. I can go directly to the stake which is only about 20ft from the array. Would you recommend I do that?

I'm not familiar with pv surge protection products. Any links? Thanks.

 

[1201]

All exposed not-current carrying metal for the entire array is required to be grounded. You must ensure that the panel frames are properly grounded to the mounting system and that the mounting system is also grounded.

690.41 System Grounding
690.43 Equipment Grounding and Bonding
690.47 Grounding Electrode System

"Exposed non-current-carrying metal parts of PV module frames, electrical equipment, and conductor enclosures of PV systems shall be connected to an equipment grounding conductor in accordance with 250.134 or 250.136, regardless of voltage. Equipment grounding conductors and devices shall comply with 690.43(A) through (D)."

Some jurisdictions will permit grounding rods at the array and not require a ground carried back to the inverter/service entrance ground (usually near the meter) and some require the ground is carried back. Always depends on the inspector and his/her interpretation of the NEC and which version of the NEC has been adopted by the local jurisdiction. In most cases you can always have grounding rods installed at the array even though you also bring the ground back to the house.

Ok thanks. I've seen conflicting opinions on this. Thanks for clarifying

 

[1201]

Using a bare grounding conductor (not inside conduit) from your array back to the bonding point is best practice from an electricians training standpoint. Ground rods at the array with metal pole mount can't hurt as it's already grounded.

You mean direct bury the grounding conductor?

 

[Drunkin Solar]

Absolutely

All large scale commercial buildings are done this way. Had some classes on it MANY years ago and I don't have the specifics in my head anymore, but I do know it allows for way more disipation.

 

[1201]

Absolutely

All large scale commercial buildings are done this way. Had some classes on it MANY years ago and I don't have the specifics in my head anymore, but I do know it allows for way more disipation.

I appreciate that. I can do that no problem. the main grounding stake is only about 20ft from the array

 

[Drunkin Solar]

It's how I'm doing my array being put in during the next couple months. Luckily I have some old 6awg laying around. Going to strip the insulation off it and bury it in the bottom of the trench, cover with 4" dirt, compact it in then run the conduit. I've got about a 100' run back to the bond.

Edit: If you have a short run I would consider using solid wire. Amazonian jungle has 8awg solid 50' roll....$28

 

[1201]

Are those a bunch of chairs upside down?

Not quite. Unirac rm10

 

[gotbeans]

Not quite. Unirac rm10

oh lol, I swear we had chairs with almost identical bases.
Can't find them on image searches but some similar ones.
In the winter we used to turn them upside down so they wouldn't blow away in the wind.. they were same color as your rack too

 

[1201]

oh lol, I swear we had chairs with almost identical bases.
Can't find them on image searches but some similar ones.
In the winter we used to turn them upside down so they wouldn't blow away in the wind.. they were same color as your rack too

Heck you might be on to something. Could be A cheap way to build a ballasted ground mount system,if those chairs are not expensive

 

[ricardocello]

I'm not familiar with pv surge protection products. Any links? Thanks.

https://www.midnitesolar.com/productPhoto.php?product_ID=284&productCat_ID=23&sortOrder=2&act=pc
https://www.amazon.com/Midnite-Solar-MNSPD-300-DC-Protector-Device/dp/B00SGGWAZ8 (weirdly, cheaper for me than direct)
Be sure to match your voltage rating, the 300V ones are good for my Victron 250/100.

 

[timselectric]

Is this going to cause issues?

Only if lightning strikes nearby, maybe.

Should I remove the ground at the inverter?

Absolutely not.
No
No
No