Bonding and Grounding Solar Components

[fisherus]

From the looks of this, I'm definitely disconnecting the one side of my array from the ground rod on that side and leave the wire between the rods attached. Then run the 6AWG wire from the ground mount to the solar shed through the conduit for neutral bonding of everything in between and get a few more lightning arresters.

 

[RCinFLA]

Soil has resistance. When lightning hits a nearby tree there can be several thousand volts per foot of earth voltage gradient radiating out 100+ feet from point of lightning hit. This is why you do not want multiple separated ground stakes.

All wires bundled together in one conduit can result in the large lightning induced ground wire current magnetically inducing current into parallel PV feed lines. This is where surge suppressors on PV lines come into play. Most SCC's have this included but putting extra surge suppressors on PV feed lines doesn't hurt.

If lightning directly hits a panel frame you are toast. Nothing is going to help much in that case.

 

[fisherus]

The two ground rods on my ground mount are only 25' apart tied together with 2 pieces of 6AWG bare stranded copper wire buried a few inches below ground level with a bare stranded copper 6AWG wire attached to one rod and all components, including the panels of my array. I can run the green 6AWG wire from the combiner box to the disconnect switches, through the conduit to the emergency shut off switches into the solar shed and Sol-Ark and then to a ground rod. This seems like my best choice. Now, if I am just bonding, could I get by with 10AWG for this instead of 6AWG?

 

[timselectric]

It needs to remain #6, until it reaches the main ground bar. It can be used to ground equipment and enclosures, along the way. But, it needs to be a wired connection for the entire length. (Don't stop and start it, on two different ground lugs, in equipment or enclosures)

 

[timselectric]

The array grounding system is useless in a bolt of direct lightning. Everything in the system will probably be destroyed and there is no grounding in the world that will prevent it. In order to prevent damage from a direct hit requires a lightning suppression system and that will be a completely separate system with air terminals and its own grounding.

This is what I believe is required and optional for grounding ground mount arrays in the NEC

(I put the question mark on the grounding electrodes for the array because I am 99% sure they are optional.)View attachment 89912




Note: If the ground mount rack is metal, it is hard to avoid some amount of grounding at the array even if there is no grounding electrodes

If the array is mounted on the house, the code allows an additional grounding electrode but does not require it. You should not do it.
View attachment 89914

I agree with this, in its entirety.

 

[fisherus]

It needs to remain #6, until it reaches the main ground bar. It can be used to ground equipment and enclosures, along the way. But, it needs to be a wired connection for the entire length. (Don't stop and start it, on two different ground lugs, in equipment or enclosures)

Thanks! I apparently didn't clarify my question behind the use of this wire. I never intended it to be used for grounding for lightning, only for connecting the neutral in my switches, combiner box and other items that need connecting along the path of the PV wire. I have yet to see it's purpose mentioned in any videos on YouTube, how it is supposed to be connected and so on. Other than always seeing it used when PV wire is ran in videos, because of it's larger size in most cases like mine that are using high voltage-low amperage strings of panels, therefore my questions regarding it's purpose and how it is to be connected.

 

[timselectric]

Do not connect it to any neutral.
It's purpose is for grounding the array, and associated equipment.

 

[fisherus]

So I just connect it to the ground lug in each box?

 

[timselectric]

The purpose of the grounding system is to provide faults a low resistance path back to the source.
In order to trip the breaker, or blow the fuse.

 

[timselectric]

So I just connect it to the ground lug in each box?

Yes

 

[timselectric]

The surge arrestors, will also connect to it.

 

[fisherus]

The surge arrestors, will also connect to it.

Thanks so much for your clarity and expertise. I finally have a handle on it. Now off to get a 500ft roll of green 6AWG stranded copper wire.

 

[DerpsyDoodler]

Thanks so much for your clarity and expertise. I finally have a handle on it. Now off to get a 500ft roll of green 6AWG stranded copper wire.

I just read over this thread and felt compelled to ask. With regard to neutral ground bond, do you fully understand where and how that is supposed to happen, at this point?

Main point is: for the entire system, this happens once and once only. timselectric described where it should happen.

Also,

@timselectric @FilterGuy

considering the long distance run from his PV mount to his house, why should he run grounding wire all the way from his solar panels? In that case, why not a grounding electrode at the panels and a grounding electrode at the house? Both are grounded and it wouldnt require 500ft of cable. At that distance, is there risk of a ground loop between the two electrodes?

 

[timselectric]

An electrical systems Grounding system, has nothing to do with the earth, other than the earth should be connected to it.
I can understand the confusion of thinking this.
Because the earth that we stand on, is also known as the ground we stand on. But, these are two different uses of the word "ground".

 

[fisherus]

I just read over this thread and felt compelled to ask. With regard to neutral ground bond, do you fully understand where and how that is supposed to happen, at this point?

Main point is: for the entire system, this happens once and once only. timselectric described where it should happen.

Also,

@timselectric @FilterGuy

considering the long distance run from his PV mount to his house, why should he run grounding wire all the way from his solar panels? In that case, why not a grounding electrode at the panels and a grounding electrode at the house? Both are grounded and it wouldnt require 500ft of cable. At that distance, is there risk of a ground loop between the two electrodes?

To begin with, I was not planning to run anything through my conduit but the PV wires from my disconnect switches at the array to the emergency disconnect switches outside my solar shed then to the SolArk12K. Then a brother-in-law of a friend who stopped by decided to spew his wisdom (or lack thereof) and tell me I had to have a neutral 6AWG wire from my panels to my inverter. Thus, my questions.

 

[FilterGuy]

An electrical systems Grounding system, has nothing to do with the earth, other than the earth should be connected to it.
I can understand the confusion of thinking this.
Because the earth that we stand on, is also known as the ground we stand on. But, these are two different uses of the word "ground".

The System of Equipment Grounding Conductors, Grounding Electrodes and Neutral-Ground bonding serves two purposes.
1) It provides a low impedance path to ensure breakers/fuses pop in the event of a ground fault.
2) It 'anchors' circuit voltage to earth potential so it does not float to some arbitrarily high value.

The word 'ground' is so overused, misused and misunderstood in electronics that I wish it could be completely retired.

 

[DerpsyDoodler]

An electrical systems Grounding system, has nothing to do with the earth, other than the earth should be connected to it.
I can understand the confusion of thinking this.
Because the earth that we stand on, is also known as the ground we stand on. But, these are two different uses of the word "ground".

Was there an answer to any of my questions here? Did my question somehow make you think I misunderstand what a ground is?

 

[DerpsyDoodler]

The System of Equipment Grounding Conductors, Grounding Electrodes and Neutral-Ground bonding serves two purposes.
1) It provides a low impedance path to ensure breakers/fuses pop in the event of a ground fault.
2) It 'anchors' circuit voltage to earth potential so it does not float to some arbitrarily high value.

The word 'ground' is so overused, misused and misunderstood in electronics that I wish it could be completely retired.

So, if his PV/mount has a grounding electrode at the mount, and the house has a grounding electrode in its vicinity, that would mean he doesn't need an extra 500 ft run from his panels to his house (or vice versa). Right? This is what I am attempting to point out. Am I somehow wrong? Frankly, I'd rather have an electrode in the vicinity than have to worry about a 500ft trench. an extra 500ft run of 6awg copper.

 

[timselectric]

Was there an answer to any of my questions here? Did my question somehow make you think I misunderstand what a ground is?

A ground rod serves little purpose, if it isn't connected to the grounding system.
And yes, it did.

 

[DerpsyDoodler]

A ground rod serves little purpose, if it isn't connected to the grounding system.
And yes, it did.

I guess I should have specified the implied EGC from the panels/mount/local equipment chassis to this grounding electrode? As for where grounding the DC circuit should happen, could it be done at either location? What are the factors to consider?