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What is recommended way to ground a ground mount solar array?

SolarHead

SolarHead

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I have a ground mount, all on galvanized steep pipe and aluminum rails that I plan to install soon, myself (DIY). I am wondering about grounding the metal solar panel frames and mount/rack. Do I need to ground it at all? If yes, do I ground it by driving a grounding rod into the ground beside the array and running a bare copper wire from one panel down to the rod in the ground? Do I need to connect all panels using the bare copper wire? Or, do I not ground at all, and run the ground in the trench with the PV wires all the way back to the inverter and ground it there inside the inverter using its' ground? Thanks to anyone that can help in advance.
 
So, if you are using Iron Ridge, they have a groudning lug you put into the rail and hook it to wire down to your grounding rod.
10 ga min wire.
 
Yep I found out IronRidge mounts are bonded meaning they are all connected so you only need a single lug, single bare wire down to a grounding rod near the array. I've been reading a lot over the past few days.

I think I am correct when I state that this is considered "equipment grounding" which is not the same as "system grounding". System grounding is your solar electrical wiring (inverter, etc). Equipment grounding is just the metal box, or the solar panels, or the rack itself (not electronics), even the combiner box case if its made of metal. Equipment grounding is more for lightning protection and not sure what else. System grounding is so that the equipment will work. Then, you "bond" system and equipment grounds only ONCE for your entire system (via ground rod driven into the ground) from what I can tell . This is so if a human touches a box, they don't complete a circuit and get zapped. Am I correct on all accounts?

Some racks other than Iron Ridge seemed to not have the bonding so you'd have to ground each solar module separately by connecting them altogether then one wire down to a grounding rod which is more wire, more lugs, more work.
 
I used off the shelf grounding lugs you can see them here-low cost in one of the photos
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Ground Mounted 9,600 watt Sol Arc do it yourself solar system-Solar Pirate

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"Equipment grounding" grounds all metal parts and electrical equipment including electronics. Typically the ground terminal on the "electronic" boards will have continuity with the metal box it is enclosed in . This is for equipment and personnel safety.
Lightning protection is a system designed to dissipate erroneous electrical charges without it damaging equipment.
The systems typically are not mixed.
The Lightning system has its own ground rods and is usually isolated from the equipment ground system.
 
I drove a ground rod by my array and connected it to the frame with 8AWG bare copper near the center of the array
 
SolarHead said:
Or, do I not ground at all, and run the ground in the trench with the PV wires all the way back to the inverter and ground it there inside the inverter using its' ground? Thanks to anyone that can help in advance.
Click to expand...
Did you come to a conclusion on this? I believe what single lines I've seen do not call for a ground in the trench, but what you mention makes sense. That said, I have a hard time understanding why you wouldn't be ok, if not better off, grounding both the equipment and the system to the same ground rod out at the array. Might want 2 wires coming off the ground rod so the lightning doesn't go through any equipment at the array.

I've definitely seen it suggested that portable generators ought to be separately grounded as well.
 
SolarHead said:
I have a ground mount, all on galvanized steep pipe and aluminum rails that I plan to install soon, myself (DIY). I am wondering about grounding the metal solar panel frames and mount/rack. Do I need to ground it at all? If yes, do I ground it by driving a grounding rod into the ground beside the array and running a bare copper wire from one panel down to the rod in the ground? Do I need to connect all panels using the bare copper wire? Or, do I not ground at all, and run the ground in the trench with the PV wires all the way back to the inverter and ground it there inside the inverter using its' ground? Thanks to anyone that can help in advance.
Click to expand...
I’m not running an equipment ground back to the panel.

I ran 8’ copper rod in ground at the array. Connected all my Module Frames together using #10 bare copper wire then Acorn nut to the ground rod.

Is this right or according to code? “No idear” but but it works. ?
 
LywWyr said:
"Equipment grounding" grounds all metal parts and electrical equipment including electronics. Typically the ground terminal on the "electronic" boards will have continuity with the metal box it is enclosed in . This is for equipment and personnel safety.
Lightning protection is a system designed to dissipate erroneous electrical charges without it damaging equipment.
The systems typically are not mixed.
The Lightning system has its own ground rods and is usually isolated from the equipment ground system.
Click to expand...
That's how the Inspector who passed my system insisted it be done but some of the more experienced guys on here think it should all be bonded to the main ground. Traditional wisdom states all grounds should be bonded.
Has anyone found a study or something that confirms which of these ideas is right.
 
Biasjo said:
I’m not running an equipment ground back to the panel.

I ran 8’ copper rod in ground at the array. Connected all my Module Frames together using #10 bare copper wire then Acorn nut to the ground rod.

Is this right or according to code? “No idear” but but it works. ?
Click to expand...
Have you had a lightning strike yet :ROFLMAO: No way to know until it passes that test.
 
Well what I did was based on what I had read, and kind of based my own judgement on what I thought was right. Thats probably not the best way to go about something but talking with a few different people, we all came to the same consensus. It was a ground rod near the array, bare copper from IronRidge ground mount rack down to the ground rod. The combiner boxes (the metal box itself) are grounded to same frame and ground rod near the array. Since I have a transformerless inverter (a Sol-Ark), I was to NOT ground the PV wires so my combiner boxes have fuse holders for both black and red. The black runs thru fuses, the red. The black is NOT grounded to the ground bus nor metal combiner box. If you have a transformer type inverter, then I don't know, I can't answer the question what you need in regards to ground or neutral, and/or bonding.

I did NOT run any ground wire in my trench. The black and red PV wires are in 2" conduit in the trench to the house and are the only 2 wires in my trenched conduit.

Out at the array, none of that is bonded, because there's no neutral to bond with. There's just the ground rod at the array and the metal rack is attached to the ground rod.

In the house, the Sol-Ark and my critical loads panel Neutral are both tied/connected to my main panels Neutral. The main panel is bonded (ground and neutral connected together) there at the main where the meter base is on the outside of home. The ground there goes down to a ground rod near the home (about 3 feet from the meter base). My home system including my solar system is bonded once and only ONCE. The ground in the Sol-Ark and critical panel are connected to ground in my main panel and from there it goes outside the home to meter base and is bonded there (the same single bond as I described above).

  • I figure I have equipment ground, which is the array ground mount frame grounded there at the array for lightning protection.
  • I figure the Sol-Ark and critical needs panel relies on Neutral that is bonded there at the meter base.
  • I have a system ground which is the ground in my Sol-Ark that makes its way to the critical loads panel and main panel and is bonded with neutral outside my home at the meter base.

I understand the bonding better since I started out with my Sol-Ark not connected to grid nor critical panel. I just hooked up 6 solar panels to it, a 48v battery bank, and a regular duplex receptacle on the wall that I temporarily installed using 3 feet of Romex. I did not have any bonding, and I couldn't get SolArk to run without throwing an error. I then figured out it was the bonding, so I ran a piece of short wire (like 8" long) from grid to ground I think it was there inside the Sol-Ark and viola I had SolArk running without throwing the error. That's when I realized the SolArk HAS to have a way for the power to get back to ground on the Neutral so it has to be bonded to ground, but you only do that ONCE in the entire system meaning your homes electrical system as well. Remove the Neutral wire and you'll see why it needs the Neutral. You cant switch or break the Neutral, it needs to bypass the disconnect/bypass switch as well. Only the L1 and L2 get switched, the N just passes by the switch/disconnect and makes it way over to main panel.

Then a few days ago, I installed the 600 model of the Midnite Solar Surge Protection Device. I asked Midnite if it would work with my combiner boxes the way I had them wired for a transformerless inverter (Sol-Ark) and they said yes. I put one SPD on each combiner box. The SPD does have a ground wire but it is only used if/when theres a lightning strike/surge and that does not disrupt/damage the Sol-Ark I was told by Midnite Solar. I dont know if the SPD's were needed but they make me feel better when theres an electrical storm happening.
 
SolarHead said:
Well what I did was based on what I had read, and kind of based my own judgement on what I thought was right. Thats probably not the best way to go about something but talking with a few different people, we all came to the same consensus. It was a ground rod near the array, bare copper from IronRidge ground mount rack down to the ground rod. The combiner boxes (the metal box itself) are grounded to same frame and ground rod near the array. Since I have a transformerless inverter (a Sol-Ark), I was to NOT ground the PV wires so my combiner boxes have fuse holders for both black and red. The black runs thru fuses, the red. The black is NOT grounded to the ground bus nor metal combiner box. If you have a transformer type inverter, then I don't know, I can't answer the question what you need in regards to ground or neutral, and/or bonding.

I did NOT run any ground wire in my trench. The black and red PV wires are in 2" conduit in the trench to the house and are the only 2 wires in my trenched conduit.

Out at the array, none of that is bonded, because there's no neutral to bond with. There's just the ground rod at the array and the metal rack is attached to the ground rod.

In the house, the Sol-Ark and my critical loads panel Neutral are both tied/connected to my main panels Neutral. The main panel is bonded (ground and neutral connected together) there at the main where the meter base is on the outside of home. The ground there goes down to a ground rod near the home (about 3 feet from the meter base). My home system including my solar system is bonded once and only ONCE. The ground in the Sol-Ark and critical panel are connected to ground in my main panel and from there it goes outside the home to meter base and is bonded there (the same single bond as I described above).

  • I figure I have equipment ground, which is the array ground mount frame grounded there at the array for lightning protection.
  • I figure the Sol-Ark and critical needs panel relies on Neutral that is bonded there at the meter base.
  • I have a system ground which is the ground in my Sol-Ark that makes its way to the critical loads panel and main panel and is bonded with neutral outside my home at the meter base.

I understand the bonding better since I started out with my Sol-Ark not connected to grid nor critical panel. I just hooked up 6 solar panels to it, a 48v battery bank, and a regular duplex receptacle on the wall that I temporarily installed using 3 feet of Romex. I did not have any bonding, and I couldn't get SolArk to run without throwing an error. I then figured out it was the bonding, so I ran a piece of short wire (like 8" long) from grid to ground I think it was there inside the Sol-Ark and viola I had SolArk running without throwing the error. That's when I realized the SolArk HAS to have a way for the power to get back to ground on the Neutral so it has to be bonded to ground, but you only do that ONCE in the entire system meaning your homes electrical system as well. Remove the Neutral wire and you'll see why it needs the Neutral. You cant switch or break the Neutral, it needs to bypass the disconnect/bypass switch as well. Only the L1 and L2 get switched, the N just passes by the switch/disconnect and makes it way over to main panel.

Then a few days ago, I installed the 600 model of the Midnite Solar Surge Protection Device. I asked Midnite if it would work with my combiner boxes the way I had them wired for a transformerless inverter (Sol-Ark) and they said yes. I put one SPD on each combiner box. The SPD does have a ground wire but it is only used if/when theres a lightning strike/surge and that does not disrupt/damage the Sol-Ark I was told by Midnite Solar. I dont know if the SPD's were needed but they make me feel better when theres an electrical storm happening.
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I think a lot of people are doing it this way, I just wish we had some form of consensus.
I am not super worried because Sol-Ark told me that they have a small separate board for the PV input that is Loaded with MOV's for lightning protection. I was told that in the event of a strike the board would be toast but it is designed to be a sacrificial lamb. They said they can ship out a replacement board ASAP and it is user installable if you have a bit of skill.
 
Biasjo said:
Not that I’m aware of?? Of course it could have snuck one in during one of those night storms..
?
Click to expand...
There was a Ham Radio thread of people showing of lightning strikes on their towers. It was pretty impressive to see three or four big scorch marks on the steel and to hear that none of their equipment was damaged. Ham Operators typically spend a lot of money on good grounding systems.

Back when I was in University and we were on summer break I would work at a local repair shop to earn tuition money. A few times people bought in VCR's and TV's that had died after a lightning strike, in all cases they were completely fried. We would change out all the dead components on the Power Supply board and then find out that every board was damaged beyond repair. After a few of those cases the owner would just tell anybody that came in with lightning damaged equipment that it was not repairable. Lots of people were not happy when they got that news. Replacing a TV or VCR was not cheap back then.
 
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robby said:
That's how the Inspector who passed my system insisted it be done but some of the more experienced guys on here think it should all be bonded to the main ground. Traditional wisdom states all grounds should be bonded.
Has anyone found a study or something that confirms which of these ideas is right.
Click to expand...
You need it to be connected to a ground rod near the array. Just like if you have a subpanel in a separate structure it needs its own ground rod(s).
 
niktak11 said:
You need it to be connected to a ground rod near the array. Just like if you have a subpanel in a separate structure it needs its own ground rod(s).
Click to expand...
When you say "own ground rods" for a subpanel are you saying you have separate grounds for your subpanels?
All grounds should be bonded together into the main panel. The only thing that is in question is the solar panel frames. Some people say they should also be bonded and some people say it should be separately grounded.
 
robby said:
When you say "own ground rods" for a subpanel are you saying you have separate grounds for your subpanels?
All grounds should be bonded together into the main panel. The only thing that is in question is the solar panel frames. Some people say they should also be bonded and some people say it should be separately grounded.
Click to expand...
Sunpanels that are in separate structures (detached garage, shed, etc) need their own ground rods
 
niktak11 said:
Sunpanels that are in separate structures (detached garage, shed, etc) need their own ground rods
Click to expand...
Unless you meant Solar Panels that is the complete opposite of what the County inspector makes you do.

A sub panel is wired back to the main panel.

Only difference is you don’t bond the neutral ground at the sub panel.
 
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I think maybe a summary to this thread would be something like this.....

  • A ground mount array needs its own ground rod and the ground mount rack itself, and any metal boxes, etc. (not your electronics) needs to be grounded to that rod. My ground mount is an IronRidge and its designed and made to bond itself when installed, so I only needed the one clamp and one wire from the rack down to the ground rod. If you have some other rack (homemade for example or some brands that are not designed with bonding/grounding in mind), then you will need to connect each solar panel frame to a wire that goes to ground rod which sounds like a pain to me but I think I would do it if I didn't have the IronRidge mount. This is considered equipment (not system) grounding.
  • A subpanel that's in the same room, or say same home or basement, needs to be connected to ground at main panel, which is then connected to ground rod. Same with the Neutral, subpanel needs to have N wire connected/passed over to main panel. White wire from N bus bar in subpanel over to N bus bar in main panel should be sufficient.
  • A subpanel that is in a power shed for example, out in your yard, or out in a barn, pole shed, pool house, whatever, needs to have its own ground rod for ground. There I am unsure if Neutral needs to be bonded or not. I do think a ground rod for earth ground would be wise there at the structure (barn, shed, etc.), but not sure if you would bond your neutral there or not but my guess would be yes you do. That would be in effect a 2nd and separate bonding and that's a question for electricians. I don't know if you'd bond there at the shed, or pass the N wire all the way back to your main panel and bond there.
  • There has to be some distance that dictates installing additional ground rod(s). I was thinking with my ground mount being 100 feet from the house and 150 feet from the inverter, and the fact that its an equipment (not system) ground, that it was totally okay to install a ground rod out near the rack since it should not interfere with my homes ground rod.
One bit of research or bit I have yet to figure out is how the N wire can zap you (I don't plan to learn by hands-on experience either). It does in fact carry power back and I treat a N wire just like its a hot wire when I am working, even with the main breaker OFF. I handle electricity like a gun that's unloaded, I treat it like its loaded even though I know its not, and have checked visually (chamber empty, multimeter shows zero). I have experimented with my clamp meter placing it on one main at a time. L1 and L2, then N and seeing that the N wire balances the loads that L1 and L2 are carrying.

Additionally, I talked with an electrician in my area about ground rods and what they call a "ground loop" which is dangerous and very bad practice. That's when you use multiple ground rods (2 or more) and they are not connected to each other via wire. A ground loop can cause someone to get involved in the loop outside just by walking in that area, and becoming part of the ground which is dangerous. I was told some inspectors in this area (I think it depends on your soil type among other things maybe) will sometimes require 2 or 3 ground rods, and they should be placed 6 feet apart and wired together with a heavy wire, usually braided aluminum or bare copper and clamps. I think 3 ground rods are usually in a triangle, 6 feet apart and all connected (if not connected together they can form a ground loop). In my area 7 years ago when I built , one ground rod was required, not sure what they require around here now or if one is still the case. The rod(s) need wet earth, meaning you can't pour concrete over the ground rod later down the road and you can't drive one into the ground under the home in a crawl space for example. They need earth that's exposed to the elements. I have heard that pouring concrete over a ground rod like if you were putting in a sidewalk years later, is against code. That's because it would cover and cause that dirt to dry out and make the ground much less effective.

I would say that DO NOT rely on my information. My knowledge is from reading and hearsay and no formal electrical education. I think some areas have their own electrical codes that differ slightly. I am not a licensed electrician. The time it takes to hire an electrician to look over your work before going live with any work, is well worth the money and highly recommended. Or paying an electrician to do the work is an excellent idea if you are at all uncomfortable around electricity.
 
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No one is getting shocked by an electrical system because they walked into an area between 2 rods that were properly grounded. Electricity takes the easiest path to ground. If you're not it, you're not getting shocked.
You are more likely to get shocked by a poorly grounded system . A bad connection between the egc and the rod can get people hurt.
 
The reason you can't pour over a ground rod in a residential setting usually has to do with access to the connection. You can pour concrete all around it as long as you can access the connection.
A ufer ground is when your ground wire is bonded to the steel in the concrete foundation of the building. No exposure.
 
Biasjo said:
Unless you meant Solar Panels that is the complete opposite of what the County inspector makes you do.

A sub panel is wired back to the main panel.

Only difference is you don’t bond the neutral ground at the sub panel.
Click to expand...
You must be misunderstanding what I'm saying. In the US, each structure needs it's own grounding electrode.

Example: Building B has a subpanel that is fed from a main panel in building A. Building B must have its own grounding electrode.

You can't just run a ground wire from building A to the building B subpanel and call it good. You definitely wouldn't pass inspection around here if you did that. There are situations where you need both a ground wire from the main panel and a ground wire to the buildings own grounding electrode, like if there are other electrical paths between the two buildings (ie metal water pipes).
 
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niktak11 said:
You must be misunderstanding what I'm saying. I the US, each structure needs it's own grounding electrode.

Example: Building B has a subpanel that is fed from a main panel in building A. Building B must have its own grounding electrode.

You can't just run a ground wire from building A to the building B subpanel and call it good. You definitely wouldn't pass inspection around here if you did that. There are situations where you need both a ground wire from the main panel and a ground wire to the buildings own grounding electrode, like if there are other electrical paths between the two buildings (ie metal water pipes
Click to expand...
Every Subpanel I have ever installed or seen installed in a detached structure has 4 wires. 2 hot, 1 neutral and one ground that all go back to the main panel.

Every one of those panels has been inspected.

Bonding screw removed.
 
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Biasjo said:
Every Subpanel I have ever installed or seen installed in a detached structure has 4 wires. 2 hot, 1 neutral and one ground that all go back to the main panel.

Every one of those panels has been inspected.

Bonding screw removed.
Click to expand...
Did the separate structure have its own grounding electrode too? If so then that's fine.
 
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