Grounding Electrode Question

Status
Not open for further replies.
H

horrorsix

Member
Location
Harrisburg PA
A homeowner contacted me about installing a ground rod at a mobile home lot. Apparently he's moving a home to a new lot and I guess there's no ground rod. Not a big deal except he says the ground under the mobile home park is slate and a rod cannot be driven in easily.

I haven't gone to look at the job yet but are there other options for a grounding electrode. Can I use the water pipes. I read article 550 but I'm still unclear of my other options.

Thank You
Shawn
 
cadpoint said:
LOL, three rednecks in NC, I bet no one between us has ever had to use a plate, here !!!
Click to expand...

Who you calling a redneck.

rt_redneck3_070709_ssh.jpg
 
Yep, I don't think Hunts carries them.

I guess you could make one.
But it would have to be coated in copper or solid with the GEC welded to it.
 
I saw the 7 different options for a grounding electrode. I guess for starters I'll look and see how the other sites are grounded.
I've never seen a ground ring being used. I'm new to this trade. Are they common? does the copper ring need to be barried?
I think I already know the answer to this but can this lot be grounded to a neighboring grounding electrode?
 
[QUOTE=horrorsix]I saw the 7 different options for a grounding electrode. I guess for starters I'll look and see how the other sites are grounded.
I've never seen a ground ring being used. I'm new to this trade. Are they common? does the copper ring need to be barried?
I think I already know the answer to this but can this lot be grounded to a neighboring grounding electrode?[/QUOTE]




The grd. ring is common in commercial work only. Yes it needs to be barried.
You can not use the neighbors.

Use a large hammer drill and dig a 30 " deep trench and lay the ground rod in it .
 
I have driven rods in slate ground. Hang a couple concrete blocks on the roto-hammer and do something else for a while. In about an hour, the rod will be in.
 
mdshunk said:
Hang a couple concrete blocks on the roto-hammer and do something else for a while.
Click to expand...

Like call the tool repair shop and tell them your bringing in one smokin' roto-hammer?
 
chris kennedy said:
Like call the tool repair shop and tell them your bringing in one smokin' roto-hammer?
Click to expand...

My thoughts as well.

I had an employee fry a Bosch demolition hammer by taping the trigger closed until all the grease had run out of it like sewing machine oil.

Roger
 
Apparently this ground rod is for the cable ground. Ive never heard of a second ground rod for cable grounding. I copied a portion of our email conversation. Let me know what you guys think.

(homeowner)
I am in need of an estimate for a relatively simple job. I need a ground rod installed. There is one catch, I am on shale, so it would require a power driver, or someone with a lot of strength.

(me)
Who told you that you needed a ground rod. There are other ways or grounding your service.

(homeowner)
This has nothing to do with the service. I need an ancillary grounding system, specifically for CATV and antennas.
I learned a few years ago, the importance of GOOD grounding. A few years ago, Comcast's superior (ha ha) grounding system cost me nearly $5000 from lightning damage.
The ground electrode is a good ten feet away and OUTSIDE the skirting perimeter. Connecting to it would create some code issues since the conductor would have to be burried (no visual verification of the connection). Connecting to the ground bus in the breaker panel could cause questions also.



What are the code issues connecting to the existing ground rod. Does anybody have any suggestions?

Thanks
 
(homeowner)
This has nothing to do with the service. I need an ancillary grounding system, specifically for CATV and antennas.
I learned a few years ago, the importance of GOOD grounding. A few years ago, Comcast's superior (ha ha) grounding system cost me nearly $5000 from lightning damage.
Click to expand...

I doult that they'd say that, off my cable box, the ground from it, has a little tag on it noting that the ground wire is to be maintained grounded, for CATV purpose.

Per 250, In your case, No! You ground point of service, it's not chained or combined.

Ok going with a plate might be difficult to get that CATV ground on there!:wink: drill a hole for a brass fitting ...

Multiple grounding lugs are allowed on a ground rod, 25 ohm limit still applies.
 
Last edited:
horrorsix said:
Apparently this ground rod is for the cable ground. Ive never heard of a second ground rod for cable grounding. I copied a portion of our email conversation. Let me know what you guys think.

(homeowner)
I am in need of an estimate for a relatively simple job. I need a ground rod installed. There is one catch, I am on shale, so it would require a power driver, or someone with a lot of strength.

(me)
Who told you that you needed a ground rod. There are other ways or grounding your service.

(homeowner)
This has nothing to do with the service. I need an ancillary grounding system, specifically for CATV and antennas.
I learned a few years ago, the importance of GOOD grounding. A few years ago, Comcast's superior (ha ha) grounding system cost me nearly $5000 from lightning damage.
The ground electrode is a good ten feet away and OUTSIDE the skirting perimeter. Connecting to it would create some code issues since the conductor would have to be burried (no visual verification of the connection). Connecting to the ground bus in the breaker panel could cause questions also.



What are the code issues connecting to the existing ground rod. Does anybody have any suggestions?

Thanks
Click to expand...
...............
View attachment 1821
 
cadpoint said:
Ok going with a plate might be difficult to get that CATV ground on there!:wink: drill a hole for a brass fitting ...
Click to expand...
Probably not. The CATV and phone guys often normally tap onto the GEC with a little Fargo connector rather than to the electrode itself.
 
080615-2058 EST

Because you have a conductor driven into rock does not mean you have a good ground. And the question exist what is a good ground? Just because you meet the code requirement does not mean you have a good ground.

Suppose your ground electrode resistance to somewhere in the earth was 25 ohms. Subject that to a 10,000 A lightning bolt. What is the voltage developed? 250,000 V.

If your home was a totally enclosed conductive and magnetic shield, all electrical connections into the home were adequately filtered, the home is supported on insulators, a lightning rod receives the lightning strike, and the lightning rod is directly connected to the ground rod, with a conductor to the home, then this shielded home and all its contents would rise to 250,000 V above some place a short distance into the earth. There probably would be no damage to anyone or thing in the home.

I conjecture you will never get a ground electrode down to 0.01 ohms. But if you did the home would still rise 100 V.

It is not not just resistance you are concerned about, but also inductance.

.
 
Status
Not open for further replies.
Top