hwy17
Anti-Solar Enthusiast
Yes, let's just say assume that is present.Your image is missing the ground at the transformer
Yes, let's just say assume that is present.Your image is missing the ground at the transformer
Size doesn't matter. The code stays the same.So in my scenario, the radio tower itself would probably be the separate air terminal...that makes sense.
And I'm not intending to muddy the waters, I realize grounding practices for a large radio tower don't apply to the guy putting a ground mount PV array in his back yard. I wonder how it's done at a large commercial solar farm?
You don't need any help. You already understand completely.So maybe this is a stupid question, but doesn't this apply in a similar way to having a grounding rod for a ground-mount solar array?
My amateur understanding has always been you want a single grounding point for your whole electrical system, which under normal residential circumstances tends to be near your feed from utilities/main breaker, everything is tied back here, and you do your NG bond in the main breaker panel.
As in, it seems like a bad idea to have a grounding rod at my shed if I am running electrical service from my home to a sub panel out there. Isn't the idea that my grounding would simply be via the ground wire back to my main panel? Shouldn't the same hold true with grounding a ground-mount array? Wouldn't you want a separate ground wire run along with your PV wire that's tied back into the grounding? I've see people talking about separate grounding rods for this.
Mostly looking for some understanding on this, as to me it seems like the same thing as the shed example.
It will, definitely.I've read a few of the recent threads and think over time the ground rod requirement may be dropped in NEC.
That's not lightning protection.From a lightning POV, tying the panel frames and mount to a ground rod at the mount which is not tied to the electrical ground would provide the best lightning protection
Depending on the distance from the building, grounded equipment can pose a shock hazzard in some areas from the earth contact surfaces without a local electrode.Another nice video from Mike Holt.
Auxilary grounding rods are not required but there is a rule that states there are no requirements on an auxiliary ground e;ectrodes. At one point in the video, he talks about CAT 5 wires and 10 penny nails for the auxiliary grounding electrode.
It has taken several years but we are starting to see both professionals and DIYrs wake up to the fact that auxiliary grounding electrodes are 1) not required and 2) not recommended.
Having said that, I am still a little uncomfortable with the code requirement for a second (not auxiliary) grounding electrode for separate buildings. I would love to see the rationale for this as well as a multi-year study of a bunch of instances where this is not done. The good news is that with just a little planning the 2nd electrode can be set up with the path to the first electrode only going through breaker boxes....but even breaker boxes are starting to get a lot of electronics in them.
From what source?Depending on the distance from the building, grounded equipment can pose a shock hazzard in some areas from the earth contact surfaces without a local electrode.
Oh, a river would be such a high conductivity, as to not pose an issue.From what source?
I have heard this for many years.
I have tested it at 1,500' and got nothing. And this was along side of a river.
You’re right, lightning wants to find ground ground, so if there is a direct path to ground from an array or and metal structure straight down, it won’t travel back to your panel .That's not lightning protection.
Lightning protection redirects lightning around and away from the equipment. (Not through it)
A Lightning protection system is built (separately) above and around the equipment that you want to protect.
Then you must be talking about great distance. (Miles? )Oh, a river would be such a high conductivity, as to not pose an issue.
The problems arise when ground is dry, and has very low conductivity.
The locak weather can cause the ground to have a different voltage from grounded surfaces, causing voltage issues.
That's not lightning protection.
Lightning protection redirects lightning around and away from the equipment. (Not through it)
A Lightning protection system is built (separately) above and around the equipment that you want to protect.
In theory, except for two rods a ways apart when a thunderstorm cloud passes overhead. The charge on the bottom of the could will induce a corresponding charge and V potential on the ground underneath. There can be significant voltage differences between ground rods when this happens, with significant currents. Granted, typically not for that long...In theory the ground wire between any 2 or more ground rods should keep differential voltage close enough to zero. That's how transmitter sites do it, multiple grounds all strapped together.
If the array is metal like the radio tower.You’re right, lightning wants to find ground ground, so if there is a direct path to ground from an array or and metal structure straight down, it won’t travel back to your panel .
This is the same for the radio tower, send it straight to ground not back to sensitive equipment.
Lighting is not going to travel 50' through a #10 grounding conductor. When the earth is less than 10' away. A lighting bolt that has just traveled miles through air, isn't going to blink at the last 10'.
These are magnitudes of differences.I've seen hits to a switch yard on surface damage electrical equipment thousands of feet under the ground.
Sometimes especially is very large distributed power systems a strike will use the copper in the power system to dispute through the entire system and not just the closest point in the earth to the where the strike hit
Not really.Then you must be talking about great distance. (Miles? )
In order to have two different local weather conditions.
But if that structure is properly bonded/grounded, there should be no difference in potential.Not really.
A structure seperated by a few yards/meters can build up a substantially different charge in the same wind stream.
Think about it...
Its static electricity.
Even IDENTICAL buildings could have different angles to the wind, different paint or siding... all accumulate a different environmental charge.
One bonded to the ground rods, will closely equalize, where the other without rods could have a different charge.
I dont pretend to understand this further, i just accept the explanation i was traind on...
Sorry, but if the EGC is ran from building to building, it is a low impedance path compared to not having an EGC and using the ground as a path.Depending on the distance from the building, grounded equipment can pose a shock hazzard in some areas from the earth contact surfaces without a local electrode.