I forgot to ground/earth my solar array... now how to fix it

Hi guys, I'm not having a good day here as I have somehow forgot to run a earth/ground for my solar array and not sure how I'm going to fix it and hoping I didn't mess up too bad here... I just got the system finally hooked up less then a week ago and it seems to be working so far so that's good I think.

The array is on a DIY ground mount framed in wood with Unistrut for rails.
I have 4x rec 310w panels run in 2 strings of 2 back to 2 charge controllers using 10awg wire with about a 90ft run one way.
The solar wires are in conduit underground from the house to the panels and then continue in conduit under the house to my room where the solar system lives.(see pics)

The solar array is the only "permanent" mounted part of this system. The inverter, batteries solar charge controllers are all mounted to a hand truck in my room with 2p breakers and MC4's to disconnect the solar panels making it a mobile system(see pic).

I think my main concern in this system is static buildup and nearby lightning strikes.

I use it to power my room off grid so far and plan to be able to power critical loads in the house during power outages.

Now from what I'm reading It would be best to somehow get another wire from the array to the houses grounding rod correct?
I think I might be able to get one more wire into the conduit but I'm not sure... its going to be tough (see update).
But I need the wire to go to the ground rod outside, not in to my room...

I'm not planning on earthing the 12v dc portion of the system since its mobile.
The inverter is earthed either by the 120v charging plug that's normally plugged into the house or by the generator inlet plug if I'm back feeding the house.
The Charge Controllers earths are tied to the inverters earth lug so they should be earthed as long as the inverter is.

Options I come up with:
See Update post below

Questions:
Should I disconnect the solar array from the charge controllers till I get this fixed or is it still safe to use for now?

I've tried to give as much info as I can but if you can think of something I missed let me know, wouldn't be the first time.

In the picture of the back of the house the grounding rod is right by the Air Conditioner and electric panel there. My room is the one to the right there with the window A/C and you can see the window in the pic where the wires come into my room.

Thanks guys, Bazzar

ps. Don't mind the mess on the back patio, spring cleaning.

Update*

I have managed to get another strand of 10awg PV wire from under the house to the panels in the conduit to use for earth/grounding. but had to pull a section of conduit under the house apart to do it.
I have located the main ground of the house and it is also tied to the metal frame of my home (doublewide).

My plan now is to use grounding lugs like https://www.ecodirect.com/product-p/ilsco-gbl-4dbt.htm or https://www.ecodirect.com/Ilsco-SGB-4-Grounding-Lug-p/ilsco-sgb-4.htm on each panel and each of the Unistrut's they are mounted to.

Run a continues piece of ground/earth wire from each lug to the new 10awg wire I just ran and attach the 2 wires with a Split Bolt Wire Connector to bond the 2 together https://www.homedepot.com/p/Commerc...pip_alternatives-_-202944398-_-100125660-_-N&.

Then attach the end of the wire under the house to the trailer frame which is earth/grounded (confirmed with multimeter) with something like this https://www.lowes.com/pd/Southwire-Lug-Al-2-14-STD-2-PK/5001719571 drilled/bolted to the frame.
Or do I need to run the wire all the way to the ground rod and attach it directly to it?

Does this plan sound like it will work for me?

Bazzar said:

Update*

I have managed to get another strand of 10awg PV wire from under the house to the panels in the conduit to use for earth/grounding. but had to pull a section of conduit under the house apart to do it.
I have located the main ground of the house and it is also tied to the metal frame of my home (doublewide).

My plan now is to use grounding lugs like https://www.ecodirect.com/product-p/ilsco-gbl-4dbt.htm or https://www.ecodirect.com/Ilsco-SGB-4-Grounding-Lug-p/ilsco-sgb-4.htm on each panel and each of the Unistrut's they are mounted to.

Run a continues piece of ground/earth wire from each lug to the new 10awg wire I just ran and attach the 2 wires with a Split Bolt Wire Connector to bond the 2 together https://www.homedepot.com/p/Commerc...pip_alternatives-_-202944398-_-100125660-_-N&.

Then attach the end of the wire under the house to the trailer frame which is earth/grounded (confirmed with multimeter) with something like this https://www.lowes.com/pd/Southwire-Lug-Al-2-14-STD-2-PK/5001719571 drilled/bolted to the frame.
Or do I need to run the wire all the way to the ground rod and attach it directly to it?

Does this plan sound like it will work for me?

Click to expand...

It's a bummer no one responded to this. So you will have a total of three wires? Two Wires coming off of your solar panel array that join together at a Split Bolt Wire Connector? You will connect a third wire somehow to this Split Bolt Wire Connector, and that wire will run all the way to your house?

I just drove a ground rod into the ground under my array and bonded copper wire to that and then to the panel frames.

If that array consists of 2 sets of parallel panels there is no need to ground them.

Yes 2 sets of 2 panels in series NOT in parallel. So 2 positives and 2 negatives and 2 charge controllers.

My plan now is to run a extra 10awg wire from the junction box at the array to the houses grounding rod or the electric panel right above its grounding buss bar.

From the junction box to the panels I will use 6aug solid bare copper with ground lugs one on each panel and unistrut frame, so 8 lugs.

From what I can tell this is the most proper way for me to accomplish the earth ground connection.

I do wonder about driving a second ground rod at the array but from what I've read I'd still need to connect the 2 rods together and am supposed to use 6awg between them so more cost and 2 rods are not recommended according to the 4 part grounding guide on the forum here.

Bazzar said:

Yes 2 sets of 2 panels in series NOT in parallel. So 2 positives and 2 negatives and 2 charge controllers.

My plan now is to run a extra 10awg wire from the junction box at the array to the houses grounding rod or the electric panel right above its grounding buss bar.

From the junction box to the panels I will use 6aug solid bare copper with ground lugs one on each panel and unistrut frame, so 8 lugs.

From what I can tell this is the most proper way for me to accomplish the earth ground connection.

I do wonder about driving a second ground rod at the array but from what I've read I'd still need to connect the 2 rods together and am supposed to use 6awg between them so more cost and 2 rods are not recommended according to the 4 part grounding guide on the forum here.

Click to expand...

Can you please link to the 4 part grounding guide on the forum? Who is the author of the guide? Mike Holt says grounding rods can actually work against you, because lightning that hits the earth nearby, can travel up the grounding rod and into your components.

AgroVenturesPeru said:

Can you please link to the 4 part grounding guide on the forum? Who is the author of the guide? Mike Holt says grounding rods can actually work against you, because lightning that hits the earth nearby, can travel up the grounding rod and into your components.

Click to expand...

This is what I'm referring to.
Part 3 gives the info on the solar panel to earth grounding.

Solar Panel FRAMES are grounded at Rack Point for Lightning issues.
There is no Ground Wire to/from solar panels, only POS & NEG DC wire.
Normally Panels are bonded together with a Wire from Fram Clamp to Frame Clamp and from there to a 6' Ground Rod or a Grounding Plate buried 24" deep into the soil.
Ground & Negative are NOT The same Thing and should NEVER BE CONNECTED.

Additionally, this is NOT enough to control Lightning. Lightning Suppressors are an extra Item, one should be located at your Combiner Box (if it has breakers) and another on your DC Panel. I use & recommend Midnites MNSP Devices for this purpose as they are some of the best available on the market. Economy does not factor into specific safety gear like Breakers, Fuses or Suppressors, these things save lives & equipment and subsequently a heap of money too. One Zot from Lightning and it can ALL go POOF and you AND your home might go with it so...

Link.
MIdnite Solar's MNSPD Line

Steve_S said:

Solar Panel FRAMES are grounded at Rack Point for Lightning issues.
There is no Ground Wire to/from solar panels, only POS & NEG DC wire.
Normally Panels are bonded together with a Wire from Fram Clamp to Frame Clamp and from there to a 6' Ground Rod or a Grounding Plate buried 24" deep into the soil.
Ground & Negative are NOT The same Thing and should NEVER BE CONNECTED.

Additionally, this is NOT enough to control Lightning. Lightning Suppressors are an extra Item, one should be located at your Combiner Box (if it has breakers) and another on your DC Panel. I use & recommend Midnites MNSP Devices for this purpose as they are some of the best available on the market. Economy does not factor into specific safety gear like Breakers, Fuses or Suppressors, these things save lives & equipment and subsequently a heap of money too. One Zot from Lightning and it can ALL go POOF and you AND your home might go with it so...

Link.
MIdnite Solar's MNSPD Line

Click to expand...

So does that mean this diagram is not correct? Solar panels and frame EGC all the way to the main grounding rod which in my case would be the one for the house since this system is plugged into the house and grounded threw the 120v plug thus effectively grounding everything into the same point?

And thanks for the info on the Lightning Suppressors I need to look into them it sounds like.
I'm guessing id need one per charge controller?
Is that correct?

If you look at the pics in the fist post you can see the 4 wires going into the box outside, they are just going into the watertight connectors and into the conduit no splicing. In another pic inside you can see them come out into the room and into MC4s then to my DC disconnect Breakers on the cart and then into the charge controllers.

The charge controllers and the inverter chassis are bonded together with a ground wire and connected to the input and output plugs of the inverter so when its plugged into a house circuit its effectively bonded/grounded threw the plug.

The only other thig I have not done is bond the Negative DC side of the battery to the Grounding system, DC System Bonding Jumper on the pic, even though most places say to.... Just seems like a bad idea in my situation.

Bazzar said:

This is what I'm referring to.

Grounding Made simpler - Part 3: Solar Panels

To get the paper, click on the orange button at the top of the screen. The subject of grounding is a complex, multifaceted subject, that is often treated as an after-thought but needs to be considered from the beginning of the design and build...

diysolarforum.com

Part 3 gives the info on the solar panel to earth grounding.

Click to expand...

Let's say you do your original idea of using a split bolt wire connector... What is the proper usage of one of those accessories? Can you attach two 12AWG wires to the split bolt connector, and then run a single 12AWG wire to the house? Or would the wire going to the house need to be a larger gauge wire, because you're basically combining two wires into one?

Panel grounding is only important for eliminating the risk of dangerous voltage being present on the panel frame due to equipment (wiring or AC inverter) failure.

With your system, DC coupled at ELV. There is no need to ground the panels.

(same applies to most RV installations)

toms said:

Panel grounding is only important for eliminating the risk of dangerous voltage being present on the panel frame due to equipment (wiring or AC inverter) failure.

With your system, DC coupled at ELV. There is no need to ground the panels.

(same applies to most RV installations)

Click to expand...

DC coupled at ELV. What does ELV stand for?

toms said:

If that array consists of 2 sets of parallel panels there is no need to ground them.

Click to expand...

Why?

The maximum DC voltage if a wire shorts to the panel or the DC/DC MPPT charger fails cannot be harmful, it is ELV (extra low voltage)

What exactly are you trying to achieve by grounding the panel frames?

(other than actually making them into a lightning rod)

toms said:

The maximum DC voltage if a wire shorts to the panel or the DC/DC MPPT charger fails cannot be harmful, it is ELV (extra low voltage)

What exactly are you trying to achieve by grounding the panel frames?

(other than actually making them into a lightning rod)

Click to expand...

While I do tend to agree with your thinking, according to the guide and some other places.

1. NEC requires that any dc circuit that operates at 50V or higher must be bonded to ground. To determine Max voltage, the NEC uses 125% of VOC for the max voltage of a single panel. Therefore even 2 12V solar panels in series might require the DC circuit to be grounded.

2. The first thing to understand is that the grounding system does not and can not protect against a direct lightning strike. What tying to earth ground can do is discharge static charge and induced current from nearby lightning strikes.

3. ELV? To me that would be under 50vdc. I run 80+vdc on each string.

From what I've read ungrounded panels can build up a static charge that can actually attract lightning...

Where I'm located we don't get much lightning and I am in a bit of a valley with plenty of things that lightning would probably rather strike then my solar panels.

The only concern to me is the whole ungrounded panels might somehow attract lightning.

So I'm trying to accomplish 2 things I guess.
1. Try and follow NEC and best practices to the best of my ability.
2. Prevent the whole panel, static charge, induced current, possibey somehow attracting the lightning thing.

Bazzar said:

Update*


My plan now is to use grounding lugs like https://www.ecodirect.com/product-p/ilsco-gbl-4dbt.htm or https://www.ecodirect.com/Ilsco-SGB-4-Grounding-Lug-p/ilsco-sgb-4.htm on each panel and each of the Unistrut's they are mounted to.

Then attach the end of the wire under the house to the trailer frame which is earth/grounded (confirmed with multimeter) with something like this https://www.lowes.com/pd/Southwire-Lug-Al-2-14-STD-2-PK/5001719571 drilled/bolted to the frame.
Or do I need to run the wire all the way to the ground rod and attach it directly to it?

Does this plan sound like it will work for me?

Click to expand...

I think the drop in ground lugs are a good idea, I am using them. Code wants an uninteruptable ground so that when you remove one panel the rest are still grounded. But I have a separate ground rod setup for the DC panels and Battery, from the AC ground. I don't know if it makes any code difference, but I don't see a DC current causing ground loop issues as AC does. And I don't want a surge through the ground system of my house from a lightning strike on my panel array.
Sorry, this probably is useless to you now, but any ground is better than none.

Steve_S said:

Solar Panel FRAMES are grounded at Rack Point for Lightning issues.
There is no Ground Wire to/from solar panels, only POS & NEG DC wire.
Normally Panels are bonded together with a Wire from Fram Clamp to Frame Clamp and from there to a 6' Ground Rod or a Grounding Plate buried 24" deep into the soil.
Ground & Negative are NOT The same Thing and should NEVER BE CONNECTED.

Additionally, this is NOT enough to control Lightning. Lightning Suppressors are an extra Item, one should be located at your Combiner Box (if it has breakers) and another on your DC Panel. I use & recommend Midnites MNSP Devices for this purpose as they are some of the best available on the market. Economy does not factor into specific safety gear like Breakers, Fuses or Suppressors, these things save lives & equipment and subsequently a heap of money too. One Zot from Lightning and it can ALL go POOF and you AND your home might go with it so...

Link.
MIdnite Solar's MNSPD Line

Click to expand...

Unless you're specifically talking about the lightning protection systems detailed in NFPA 780, you're unlikely to salvage anything following a direct strike from lightning or even a bolt that lands within a few meters of your house. Maybe if the bolt lands a bit further away, those components could then save things. I understand there is some mitigation to the damage caused from side-flashes.

Bazzar said:

While I do tend to agree with your thinking, according to the guide and some other places.

1. NEC requires that any dc circuit that operates at 50V or higher must be bonded to ground. To determine Max voltage, the NEC uses 125% of VOC for the max voltage of a single panel. Therefore even 2 12V solar panels in series might require the DC circuit to be grounded.

2. The first thing to understand is that the grounding system does not and can not protect against a direct lightning strike. What tying to earth ground can do is discharge static charge and induced current from nearby lightning strikes.

3. ELV? To me that would be under 50vdc. I run 80+vdc on each string.

From what I've read ungrounded panels can build up a static charge that can actually attract lightning...

Where I'm located we don't get much lightning and I am in a bit of a valley with plenty of things that lightning would probably rather strike then my solar panels.

The only concern to me is the whole ungrounded panels might somehow attract lightning.

So I'm trying to accomplish 2 things I guess.
1. Try and follow NEC and best practices to the best of my ability.
2. Prevent the whole panel, static charge, induced current, possibey somehow attracting the lightning thing.

Click to expand...

Grounding solar panels whil do you no good, it is more likely to atract lightning since you place ground higher than the sorounding area . ither way it whil fry your solar panels if the lightning hits it . it is bether to have a rod placed higher than your solar aray in the ground somwhere nearby and have a high current protection and fuse between your inverter/batteries , and your as safe as you can get.

TommyBredesen said:

Grounding solar panels whil do you no good, it is more likely to atract lightning since you place ground higher than the sorounding area . ither way it whil fry your solar panels if the lightning hits it . it is bether to have a rod placed higher than your solar aray in the ground somwhere nearby and have a high current protection and fuse between your inverter/batteries , and your as safe as you can get.

Click to expand...

PLEASE find some CREDIBLE info to support that pile of malarkey. You better Ground the metal (aluminium racking & panels frames) because they do get zapped. This is why we use Lightning Protection devices and they were invented over 100 years ago...

NO Respectable SOLAR INSTALLER with credentials would ever install anything without Surge & Lightning protection accounted for. Neither would it pass inspections. BEWARE of info posted by folks on the, engage Critical Thinking and remember every Nation & Region has their own Electrical Codes & Requirements and they vary somewhat. REMEMBER, It's Your Solar Gear, Batteries, INVESTMENT and your family's lives so be cautious of advice given that risks any of it in any way.