Grounding pv panels, safety disconnect switch and dc surgeprotector

Cheap 4-life

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Thanks in advance for your assistance.
When I installed my roof mount array (metal roof) I had the understanding that the array should be grounded to its own ground rod. I understand now that might not be correct.
Now I’m planning to add an outdoor pv safety disconnect switch and a dc surge protector. I do not have a ground wire running with the pv wires. The pv wires are in plastic conduit in the attic space.
How do I ground the safety disconnect and the dc surge protector?
I was hoping to mount the dc surge protector directly onto the pv disconnect switch. The combiner for the pv is inside the house. I want to put the pv disconnect after the combiner on the outside of the house.
Do I have to disconnect the array from it’s ground rod and run a ground wire along with the pv wires then into the pv disconnect. I was thinking that I don’t want to bring the dc surge/lightning into the attic on the ground wire. I guess I could mount the dc surge protector in the soffit instead of on the safety disconnect. That way surges are stoped before entering the house..
Thoughts?
Additional info. I am connected to the grid that also has a ground rod for the main panel
 

anadiner

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Thanks in advance for your assistance.
When I installed my roof mount array (metal roof) I had the understanding that the array should be grounded to its own ground rod. I understand now that might not be correct.
Now I’m planning to add an outdoor pv safety disconnect switch and a dc surge protector. I do not have a ground wire running with the pv wires. The pv wires are in plastic conduit in the attic space.
How do I ground the safety disconnect and the dc surge protector?
I was hoping to mount the dc surge protector directly onto the pv disconnect switch. The combiner for the pv is inside the house. I want to put the pv disconnect after the combiner on the outside of the house.
Do I have to disconnect the array from it’s ground rod and run a ground wire along with the pv wires then into the pv disconnect. I was thinking that I don’t want to bring the dc surge/lightning into the attic on the ground wire. I guess I could mount the dc surge protector in the soffit instead of on the safety disconnect. That way surges are stoped before entering the house..
Thoughts?
Additional info. I am connected to the grid that also has a ground rod for the main panel
I've been allowed, given permission by Code, to consider my inverter on/off switch as a disconnect ss long as the inverter is grounded.

Although that wouldnt apply to u because Im doing a multiple small units to make a bigger one (Im attempting to not need s combiner box)

For u, Im in agreement with disconnect on outside of house. I would put the combiner box there also which of course should be grounded.

And yes on disconnect ground from pv moving to disconnect... u do realize ur correct of an electrical surge movement I hope. Im saying yes lightening will travel to x pt.

And btw, while rare, it does happen. Happened to me once yrs ago. Also had an electrical surge fry wires then cone to a stop - few yrs ago.

Was expensive replacing the wires btw BUT saved everything else.

Good luck. Appears u have to redesign ur rig. Thats what I would do. Good time to upgrade tho.
 

Cheap 4-life

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I was informed on a different group that the pv panels ground is fine going directly to its own ground rod as long as it’s far away from the other (main panels) ground rod. And that it’s recommended to put the dc SPD close to the panels before the pv wires enter the house. Connecting the SPDs ground to the pv panels ground rod. The safety disconnect can have its metal case grounded to the AC (main panels) ground.
 

anadiner

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I was informed on a different group that the pv panels ground is fine going directly to its own ground rod as long as it’s far away from the other (main panels) ground rod. And that it’s recommended to put the dc SPD close to the panels before the pv wires enter the house. Connecting the SPDs ground to the pv panels ground rod. The safety disconnect can have its metal case grounded to the AC (main panels) ground.
U 'get' why the distance rt? Its because thats a surge stopping pt where things fry... remember I went thru that.

Maybe I missed it before... 2 arrays. I would definitely ground the 1st far from main before entering house. Thats a 100%.

I have image of this setup being far from combiner a disconnect. Am I wrong?
 

Cheap 4-life

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U 'get' why the distance rt? Its because thats a surge stopping pt where things fry... remember I went thru that.

Maybe I missed it before... 2 arrays. I would definitely ground the 1st far from main before entering house. Thats a 100%.

I have image of this setup being far from combiner a disconnect. Am I wrong?

I do understand why ground rods should be kept far away from each other.
Only one array. The array is on the roof of the house 50ft from the chargecontroller. The combiner is inside the house on the wall next to the chargecontroller and future disconnect is to be placed on the outside of the house on the other side of that wall
 

anadiner

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I do understand why ground rods should be kept far away from each other.
Only one array. The array is on the roof of the house 50ft from the chargecontroller. The combiner is inside the house on the wall next to the chargecontroller and future disconnect is to be placed on the outside of the house on the other side of that wall
Ok. Are u gonna leave combiner box there or move to outside? I would put it outside next to disconnect then ground both but thats just my preference. .

I thought u mentioned grounding outside panels far from main panels hence why I thought 2 arrays.

Understand what ur doing now. Im stuck on running SPD ground in with pv panels ground. Its standard to ground ur disconnect.

Im kinda lost with original question.

Having had things get zapped, 1 lightening - other a surge, Im all about grounding everything I can hook a wire to.

Uve got it covered. Lightning hits panels, stop. Power surge, combiner box and disconnect ground will stop. Even if lightning hit metal box, ur covered.
 

740GLE

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Midnight solar combiner box’s has room for surge suppression and is weather tight for a reason.

Look like the best option for straightforward clean install
 

Cheap 4-life

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Midnight solar combiner box’s has room for surge suppression and is weather tight for a reason.

Look like the best option for straightforward clean install
I already have my combiner in the house. I wanted the ability to easily turn off individual strings and due to limited space on the roof. If I had it to do again I would install the combiner on the outside wall next to the future disconnect. Didn’t think of that. I was just thinking that if the combiner was on the roof I couldn’t easily get to it. But in my case the surges on the pv dc wires or pv dc ground would run through the attic till they hit the SPD on the outside wall if the SPD was installed on the combiner box. This probably isn’t good. So it seems like to avoid that I will need an SPD right at the pv panels installed on its own box. The ground of the SPD then wired directly to the pv panels ground rod. Then ground the combiners case and disconnects case to the main panels AC ground rod.
 

Cheap 4-life

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Do I? I guess your right...
I’m not buying 3 SPDs for just the solar.
Back to putting the PV SPD on the pv safety disconnect.
Doing that I’m thinking the surges will most likely go directly to the pv ground rod thru the larger gauge uninsulated ground wire. If any surges go thru the pv + and - then it will hit the SPD and travel to the AC main panel ground rod.
Is that ok? The surge protector only uses AC ground for the short duration of a surge.
 

anadiner

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- usually on/off breakers in combiner box can shut down a string. U know... each string brings in x amps so u get x amp breaker. The fuse ones r different tho.

Also, it seems like u mentioned only 2 breakers. If that was u, I assumed u had done something diff cuz might not even need combiner box since only 2 strings... depends on the numbers.

U did mention u wanted easy access. Honestly, I ignored that just from going thru personal drama... like sorry for inconvenience but be safe.

- goal here for me is to prevent (stop) surge dead in tracks at initial pv dc ground. That and grounding c box should shield it.

Anyway, the time a surge fried wires but that saved (stopped) the surge rt there - the way I did that = used a low gauge (able to carry the amps) BUT aluminum base. Note: this was pt where bulk power entered. Like ur pv modules input.

That aluminum will fry and snap. It even crystalized the sand around it. Stopped the surge from getting to breakers tho.

Im saying do this rt and a surge wont go thru attic and zap SPD.

Surges r scarey. U'll smell wires burning and hear noise. Theres rush of panic where u run to the disconnect.

Theres comfort in knowing ur ok even in a massive electrical storm. I get it. Dont c grounding spd i. With modules adding more protection. Opposite actually.
 

740GLE

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Also if your putting a solar disconnect before the combiner box, won’t you need a disconnect per string?

I think you’re starting to realize why people design their systems with the combiner box close to the panels with a home run to the SCC
 

Cheap 4-life

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Also if your putting a solar disconnect before the combiner box, won’t you need a disconnect per string?

I think you’re starting to realize why people design their systems with the combiner box close to the panels with a home run to the SCC
Planning to put Disconnect after the combiner. So only one disconnect needed. Yes I am realizing that putting the combiner on the roof is better. I will plan for that on the next house. For this one I’ll depend on the pv ground rod/wire and depend on the SPD to ground any surges on the - and + pv wires. I know this isn’t optimal because any surges on the + and - should be stopped before entering the house. I’m hoping the pv ground rod/wire takes care of that.
 

Cheap 4-life

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- usually on/off breakers in combiner box can shut down a string. U know... each string brings in x amps so u get x amp breaker. The fuse ones r different tho.

Also, it seems like u mentioned only 2 breakers. If that was u, I assumed u had done something diff cuz might not even need combiner box since only 2 strings... depends on the numbers.

U did mention u wanted easy access. Honestly, I ignored that just from going thru personal drama... like sorry for inconvenience but be safe.

- goal here for me is to prevent (stop) surge dead in tracks at initial pv dc ground. That and grounding c box should shield it.

Anyway, the time a surge fried wires but that saved (stopped) the surge rt there - the way I did that = used a low gauge (able to carry the amps) BUT aluminum base. Note: this was pt where bulk power entered. Like ur pv modules input.

That aluminum will fry and snap. It even crystalized the sand around it. Stopped the surge from getting to breakers tho.

Im saying do this rt and a surge wont go thru attic and zap SPD.

Surges r scarey. U'll smell wires burning and hear noise. Theres rush of panic where u run to the disconnect.

Theres comfort in knowing ur ok even in a massive electrical storm. I get it. Dont c grounding spd i. With modules adding more protection. Opposite actually.
3 breakers. I do now realize the inconvenience of having the breakers on the roof instead of inside isn’t worth the risk
 

MarkSolar

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When I installed my roof mount array (metal roof) I had the understanding that the array should be grounded to its own ground rod. I understand now that might not be correct.
Do I have to disconnect the array from it’s ground rod and run a ground wire along with the pv wires then into the pv disconnect. I was thinking that I don’t want to bring the dc surge/lightning into the attic on the ground wire.
Thoughts?
Additional info. I am connected to the grid that also has a ground rod for the main panel
I learned a lot from Mike Holt, he's an authority on the NEC and electrical safety and runs an online forum where you can ask questions. Here's a video he did on auxiliary ground rods, if you go to 3:33 he talks specifically about solar arrays and what the code allows/requires with regards to ground rods.
 

rcrracer

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Might not have anything to do with solar but the NEC requires disconnects to be within 50' and within sight of whatever you are working on.
 

Cheap 4-life

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well That video didn’t help the grounding make anymore sense to me.
Their saying that a ground from the panels frames to its own ground rod isn’t needed. Well that means that any surge has to travel thru the equipment till it finds the main panels ground rod. Couldn’t that possibly destroy equipment.
Their also saying code requires the array to have its own ground rod.
They are also saying lightning could travel up the arrays ground rod/wire and thru panels and equipment possibly destroying equipment.
I personally feel like lightning surges are not going to travel up the arrays ground wire because the surge already found ground.
Such a confusing issue
 

740GLE

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Lightning in can actually travel from the ground up, it’s pretty un predictable.

We had a lightning strike behind our house. We live in a hill in a state known for granite, a pine tree (about 30” in diameter) took a direct shot right down the center. The charge followed the ground path above granite ledge and shoot out of the ground and made contact with our hose spigot on the back of our house, which is grounded to our panel ground. We heard a buzzing lights dimmed in the house and by the time I made it to the main panel and opened the breaker it was all over. Amazingly enough only damaged was a fried GFIC which is right by the panel.

Ohh and the tree is about 100-150 feet directly behind out house.

I think the goal is to make that path the easier possible via a path that you set up not through house plumbing or the conductors in the walls.

Check out some Alt E Store you tube videos. That have some nice tutorials on grounding.
 

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