Can I run a grounding wire 150ft from PV array to inverters?

[Konvett]

I recently installed a PV array 150 feet from my inverters. I have two EG4 6500EXs. They have an AC Input from my utility company service panel which has is earth grounded. The inverters then feeds my critical load panel. Is it standard practice to run a 150 ft 6 AWG bare copper wire from the PV rails (IronRidge equipment so that the rails and panels are grounded together) to the inverter, thus grounding the system through to the utility company service panel? Or should I instead put grounding rods in at the array and run the copper wire there instead?

In this commonly circulated video from Mike Holt on grounding, he mentions that you want to keep a grounding electric conductor as short as possible (32:08 in this video).

 

[niktak11]

Put in a ground rod or two by the mount and ground to that

 

[Mike 134]

Run a grounding wire (same size as your PV wires) back to the inverter grounding bar then continue with the AC wires back to the service panel.

 

[timselectric]

A grounding conductor is required to be ran with the solar conductors to the inverter and connected to the properties original grounding system.
An auxiliary rod at the array is allowed (but not recommended or required). But, it doesn't negate the required grounding conductor.

 

[BartHenry]

Add a rod at the array

 

[timselectric]

Add a rod at the array

That's a bad idea.
If there's a nearby lightning strike. The auxiliary rod will send it to your inverter.

 

[MurphyGuy]

A grounding conductor is required to be ran with the solar conductors to the inverter and connected to the properties original grounding system.
An auxiliary rod at the array is allowed (but not recommended or required). But, it doesn't negate the required grounding conductor.

Grounding is all about resistance. Why would you NOT want more ground rods?

Your comment doesn't make sense.

OP should sink a ground rod (or two) next to the array and bond it back to the main panel ground at the house. Your system must be grounded to the main ground at the house, but having extra grounds is almost always a good idea.

 

[niktak11]

A grounding conductor is required to be ran with the solar conductors to the inverter and connected to the properties original grounding system.
An auxiliary rod at the array is allowed (but not recommended or required). But, it doesn't negate the required grounding conductor.

I think it IS required to have grounding at the array unless you live in an area where a ground mount array doesn't count as its own separate structure

 

[timselectric]

Grounding is all about resistance. Why would you NOT want more ground rods?

Your comment doesn't make sense.

OP should sink a ground rod (or two) next to the array and bond it back to the main panel ground at the house. Your system must be grounded to the main ground at the house, but having extra grounds is almost always a good idea.

 

[teal95]

I worked for a company putting up 400' towers for cell phones. A ring went all the way around the building in the middle about 10' out from the building, 4/0 bare, buried about 1' down. A leg also went to each guy wire anchor and was tied in. Every 10' along all the wiring a 6' rod was driven in. Everything tied to that, including a ring all the way around the building inside just below the ceiling.

 

[timselectric]

I worked for a company putting up 400' towers for cell phones. A ring went all the way around the building in the middle about 10' out from the building, 4/0 bare, buried about 1' down. A leg also went to each guy wire anchor and was tied in. Every 10' along all the wiring a 6' rod was driven in. Everything tied to that, including a ring all the way around the building inside just below the ceiling.

That's lightning protection for the metal tower.
Not electrical grounding.

 

[teal95]

All the electronics inside the building was tied to it also. There was no separate "electrical" grounding.

 

[timselectric]

All the electronics inside the building was tied to it also. There was no separate "electrical" grounding.

Probably a good idea, if the electronics are inside the ring.

 

[MurphyGuy]

Mike Holt has some very good videos, but he is not an electrical engineer. He's an NEC expert, and as I understand, he's a good teacher as well.

He's talking about CNC machines INSIDE buildings. Since it is ridiculously unlikely (has probably never happened anywhere ever) that a lightening strike could hit a CNC machine inside a metal building (basically a giant Faraday cage), then the argument for an auxiliary ground rod (even if bonded), would make sense because it (lightening strike) could set up a current loop using the earth.

That is not the case for something outside.

The BR107170 article he referenced is an interesting read because I had an experience with a computer controlled CNC system having noise problems due to other machinery. My solution was to loop all the conductors through ferrites, which solved the problem.

 

[timselectric]

Mike Holt has some very good videos, but he is not an electrical engineer. He's an NEC expert, and as I understand, he's a good teacher as well.

He's talking about CNC machines INSIDE buildings. Since it is ridiculously unlikely (has probably never happened anywhere ever) that a lightening strike could hit a CNC machine inside a metal building (basically a giant Faraday cage), then the argument for an auxiliary ground rod (even if bonded), would make sense because it (lightening strike) could set up a current loop using the earth.

That is not the case for something outside.

The BR107170 article he referenced is an interesting read because I had an experience with a computer controlled CNC system having noise problems due to other machinery. My solution was to loop all the conductors through ferrites, which solved the problem.

All that I can do is provide you with the information. What you choose to do with it is up to you.
You evidently didn't watch the entire video.

 

[Darren67-72]

Timselectric, you are of great assistance, all around this site. I thank you for your patience with ALL of us!
Today I will jump in on a "ground" issue. And, I never do". My poa requires a rod at every location (each building) and at solar array.
The place is riddled with ground rods.
I don't agree with him. But, sometimes. This is what is required.

 

[timselectric]

Timselectric, you are of great assistance, all around this site. I thank you for your patience with ALL of us!
Today I will jump in on a "ground" issue. And, I never do". My poa requires a rod at every location (each building) and at solar array.
The place is riddled with ground rods.
I don't agree with him. But, sometimes. This is what is required.

If you have a good relationship with them. And they are open to discussion. See if you can sway their old school mindset. If not, then do what you have to. If it were my personal property I would remove it after the inspection. But, I've been working with (AKA "training") my local inspectors for a while. It all comes down to their interpretation.

 

[niktak11]

Timselectric, you are of great assistance, all around this site. I thank you for your patience with ALL of us!
Today I will jump in on a "ground" issue. And, I never do". My poa requires a rod at every location (each building) and at solar array.
The place is riddled with ground rods.
I don't agree with him. But, sometimes. This is what is required.

It makes sense to have separate ground rods for each structure, even moreso when they are far apart.

 

[timselectric]

It makes sense to have separate ground rods for each structure, even moreso when they are far apart.

I can sort of agree if it's a building. But the definition of a "structure" has gotten abused. And, that would be a systems grounding electrode. If there's nothing there but equipment. There should only be equipment grounding.
That being said, I only install grounding electrodes at the service. When I get a stubborn inspector from an area I don't frequently work in. I do what they ask.

 

[Konvett]

I can sort of agree if it's a building. But the definition of a "structure" has gotten abused. And, that would be a systems grounding electrode. If there's nothing there but equipment. There should only be equipment grounding.
That being said, I only install grounding electrodes at the service. When I get a stubborn inspector from an area I don't frequently work in. I do what they ask.

Illustrated in this photo is the location of my two solar arrays and my inverters/service panel. One of the arrays is on my garage (top left in the photo) which would require 150 ft of cable to ground to the inverters. The second array on the house (closer to the inverters in the photo) is about 90 to 100 ft away. I'm planning to run a single 150 ft 6 AWG grounding copper wire from the array on the garage to the inverter and attach a shorter grounding wire to the second array and have it meet in the middle of the longer wire. Both will be grounded to the inverters only this way.