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diy solar

Help me Install 3 EG4 Mini Split Solar Heat Pumps

MrM1 said:
Looking at the Mike Holt videos for several years, I know he has tried to get the NEC code to see it differently, The main idea as Understand what Mike advocates for is that you do not what it going thru house and all the electrical system to get to ground, but you do want it part of the main whole house grounding system, not a separate grounding system. Thus I route the array grounds to their own rod, but that rod is tied to the whole house grounding system thru the earth via 6 gauge wire.

My understanding is that you can have multi rods as long as they are tied together. This does not constitue 2 separate grounding systems nor 2 places of potential difference.
Click to expand...
This whole thing does my head in. Especially when you have multiple buildings on the same system. We went with one per building plus one at the ground mounts. Almost all of my runs are in oversized conduit so I could add if needed. Sometimes even have an extra empty run of conduit also buried in the same trench for future expansion. Plus one to two runs of smaller stuff for fiber.
 
MrM1 said:
My understanding is that you can have multi rods as long as they are tied together. This does not constitue 2 separate grounding systems nor 2 places of potential difference.
Click to expand...
Multiple ground rods are considered auxiliary electrodes. While not required, they are still currently allowed (but not recommended).
They must be connected together for electrical safety. But connecting them together creates an equipment Hazzard.
Because it lessons the resistance over distance. Compared to the earth itself.
Which is why they aren't recommended.
When lightning strikes it creates a gradient pulse across the earth. This pulse dissipates over distance from the resistance in the earth. But the EGC that ties the auxiliary electrodes to your grounding system has less resistance. So it allows the pulse to cover more distance.
By installing auxiliary electrodes. You are increasing your chances of equipment damage. Because you are essentially reaching out to a larger area. So more of the strikes are within reach of your system.
 
timselectric said:
Multiple ground rods are considered auxiliary electrodes. While not required, they are still currently allowed (but not recommended).
They must be connected together for electrical safety. But connecting them together creates an equipment Hazzard.
Because it lessons the resistance over distance. Compared to the earth itself.
Which is why they aren't recommended.
When lightning strikes it creates a gradient pulse across the earth. This pulse dissipates over distance from the resistance in the earth. But the EGC that ties the auxiliary electrodes to your grounding system has less resistance. So it allows the pulse to cover more distance.
By installing auxiliary electrodes. You are increasing your chances of equipment damage. Because you are essentially reaching out to a larger area. So more of the strikes are within reach of your system.
Click to expand...
Well I'm not installed yet. So tie them all together - Array, Equipment grounding conductors (EGC), etc - and run them all to the main panel ground busbar and out to the main ground via the GEC bypassing the aux ground ? My earlier understanding was you did not what this. But you also did not want to separate systems.

I'm open to doing it different. I am at the beginning stages of install
 
MrM1 said:
Well I'm not installed yet. So tie them all together - Array, Equipment grounding conductors (EGC), etc - and run them all to the main panel ground busbar and out to the main ground via the GEC bypassing the aux ground ?
Click to expand...
This is what I would do.

How far apart are the two ground rods?
Distance between is what you want to avoid. Since if installed, they must be connected together.
Personally I avoid auxiliary electrodes, whenever possible.
All grounding must be tied together. How this is done is up to the installer.
 
timselectric said:
This is what I would do.

How far apart are the two ground rods?
Distance between is what you want to avoid. Since if installed, they must be connected together.
Personally I avoid auxiliary electrodes, whenever possible.
All grounding must be tied together. How this is done is up to the installer.
Click to expand...
What say you for multiple buildings? One per (sub)panel or just one total?
 
SilverbackMP said:
What say you for multiple buildings? One per (sub)panel or just one total?
Click to expand...
If it's required by the inspector to add one at separate buildings. Then you must to pass inspection.
If not, don't.
Either way you are required to run an EGC back to the existing grounding system.
My inspector required it for my detached garage. I disconnected it after inspection.
NEC is always evolving. It will catch up, eventually.
 
Thanks for the discussion. I know it can get tricky depending on the installation - like what SilverbackMP is asking. It will probably be a while before I can install my panels as I need a new roof first, so in the mean time I will just run the 12k off the grid. Mine is supposed to arrive on Tuesday am I am worried that if they use a full size 18 wheeler, they will have problems in my neighborhood with delivery because we have huge live oak trees everywhere.

By the way your installation job is really neat looking and I would not have even thought of the valence idea, very nice.

RDuke
 
timselectric said:
If it's required by the inspector to add one at separate buildings. Then you must to pass inspection.
If not, don't.
Either way you are required to run an EGC back to the existing grounding system.
My inspector required it for my detached garage. I disconnected it after inspection.
NEC is always evolving. It will catch up, eventually.
Click to expand...
I don’t have an inspector. My semi-retired electrician is my inspector lol.

My power shed, my mom’s house, my shop, two other outbuildings, and other future projects (second workshop, greenhouse, my house) are on/will be on an interconnected off grid set up. Probably will remain all SMA to keep it KISS as much as possible and redundant for spares.
 
The good thing about rural areas in some “flyover states?”

No inspections.

The bad thing?

No inspections.

If I’m jacking something up, sometimes there’s no one readily available to ask a question to.
 
SilverbackMP said:
The good thing about rural areas in some “flyover states?”

No inspections.

The bad thing?

No inspections.

If I’m jacking something up, sometimes there’s no one readily available to ask a question to.
Click to expand...
But you are not required to be inspected , or you're just doing it without a permit
 
MrM1 said:
But you are not required to be inspected , or you're just doing it without a permit
Click to expand...
No inspections, no permits required except septic (two page application, $50 fee), no statewide NEC adoption, no zoning, no hoops, no BS.

By Gawd Missoura. Everything Texas imagines itself to be.
 
timselectric said:
How far apart are the two ground rods?
Distance between is what you want to avoid. Since if installed, they must be connected together.
Click to expand...
For the house main panel I have 2 grounding electrodes (rods) 6+ feet apart.

Then There is 20 ft between the array ground and the house ground system. These are connected along the ground via #6
 
Yea I am not looking forward to having my solar setup inspected. In 2021 I had GA Power move my service underground. I paid a local electric company to do most of the work. I asked them drive 2 new 10 ft rods for the ground at the new service disconnect panel, and I bonded my copper water pipe inside that panel where the NG bond is. The inspector wanted me to remove the water pipe #6 solid and attach it to my intersystem bonding bridge by running it outside my house. What??? So I paid for a copy of the code just to show the guy that was not right, and he never came back. My electrician said yea , he just signed off on it anyhow. Of course that was after I paid another 100 bucks for the 2017 code. We are on 2020 now. Granted it would have worked, but nowhere does it say that is how to use the intersystem bonding bridge. I was not impressed. So I am dreading how the same guy may inspect a more complicated installation.

RDuke
 
MrM1 said:
For the house main panel I have 2 grounding electrodes (rods) 6+ feet apart.

Then There is 20 ft between the array ground and the house ground system. These are connected along the ground via #6
Click to expand...
20' isn't going to make much difference. But I still wouldn't.
 
timselectric said:
This is what I would do.

How far apart are the two ground rods?
Distance between is what you want to avoid. Since if installed, they must be connected together.
Personally I avoid auxiliary electrodes, whenever possible.
All grounding must be tied together. How this is done is up to the installer.
Click to expand...
Tim, my setup is in the country, and has no inspectors or codes to comply with. I do want safe though.
My panels will be ground mounted on a pipe frame and Iron Ridge mounts. 6 pipes sunk 5 feet deep per rack.
They are well grounded without a ground rod.
They are about 90 feet from where my main breaker panel/ground rod will be.
With no inspector looking over your shoulder, would you skip running a ground wire from the PV panels to the main breaker panel?
I am going to use a Midnite Solar 600v SPD in the mechanical room on each PV circuit, beside my main panel to protect my inverters.
 
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