Grounding

[WorldwideDave]

Just looking at the way, my existing home has its main panel and disconnects and power meter, I noticed it has a ground wire coming out of the main load center into a very large copper rod that is going down into the Earth. It is probably half inch or 5/8 diameter, copper.

I noticed on the front of the panel on the outside near the power meter there is also a green solid core ground wire that runs up to the roof. I believe it connects to a combination of devices, including our old Bell, telephone landline system, coax cable from, a cable TV installation, possibly from a DIRECTV dish on our roof, and definitely from our fiber optic cable Internet line.

We also have a sub panel. I’m fairly certain that does not connect to any copper pipe. I believe the ground wire probably if it has one goes back to the main load center and connect to the ground bus over there. I can take the cover off and inspect to be sure.

I guess my question is… If we have one large single-story house with two panels in it, why is the sub panel not supposed to go to an earth grounding rod?

I watched some videos yesterday explaining how bonding and grid tie inverters work… Now I’m trying to understand how non-solar applications work.

 

[Bluedog225]

Single ground rod. All stuff runs back to the main panel. Otherwise bad stuff can happen.

Others will be along with fancier words.

And lots of grounding threads here. Look for timselectric posts.

 

[robby]

Even better multiple ground rods that are all bonded together and run back to the Panel

 

[Bluedog225]

Yeah. Robby is right. I keep forgetting. Two ground rods not less than 6’ apart. (but not too far apart) Single conductor to main panel. It serves as a single earth point.

But that’s new stuff. I only have one at home (1956).

Still nothing at the sub panel.

 

[WorldwideDave]

My understanding of the earth ground a.k.a. grounding rod was in case lightning strikes. Somehow, it prevent fires. Am I wrong?

 

[Bluedog225]

My understanding of the earth ground a.k.a. grounding rod was in case lightning strikes. Somehow, it prevent fires. Am I wrong?

yes. You are wrong. Much to study up on.

 

[WorldwideDave]

Can you recommend a thread here on the forums or a YouTube video? Just want to learn.

 

[Bluedog225]

Sure. I’m not the right guy. And my terms are not the proper words. But…

-Only one neutral ground bond at the main panel.
-Everything connected (bonded).
-only one earth ground consisting of 2 ground rods not less than 6 feet apart, and not further apart than the length of the rod, connected to the main panel with a continuous conductor.
-sub panel connected back to main with an appropriately sized conductor.
-lightning is a whole other thing.
-electricity has to flow. The bonding stuff makes the electricity flow through the overcurrent protection device and interrupts the flow.
-the equipment grounding conductor (ground) keeps everything at the same potential and touch safe.

Search @timselectric posts and read 2 dozen. He actually knows this stuff.