# Ground rod



## jbfan (Jan 22, 2007)

I am wireing a small shed with 120/240/ 30 amp. and was installing the ground rod last night.

Well, I still have 18" above the ground that does not want to move.
Would you add another rod, and cut the first one short and connect them together, or abandon the first and connect to the second one?
Or does anyone have a super slick way to get that last 18" into the ground?


----------



## chenley (Feb 20, 2007)

More the merrier. I would just cut the 18" off put in another one 6' from it and connect them together.


----------



## Bkessler (Feb 14, 2007)

If you think a second one will be tough to drive in put it at a sharp angle.


----------



## raider1 (Jan 22, 2007)

You must have 8' of length of the ground rod in contact with the earth, see 250.53(G), so cutting off 18" would not meet this requirement unless the ground rod was a 10' rod.

Also, did the ground rod meet the 25 Ohm requirement of 250.56? If not you need a second rod anyway.

Chris


----------



## randomkiller (Sep 28, 2007)

raider1 said:


> You must have 8' of length of the ground rod in contact with the earth, see 250.53(G), so cutting off 18" would not meet this requirement unless the ground rod was a 10' rod.
> 
> Also, did the ground rod meet the 25 Ohm requirement of 250.56? If not you need a second rod anyway.
> 
> Chris


 
He did say cut that one and add another, not cut it and use it.


----------



## raider1 (Jan 22, 2007)

randomkiller said:


> He did say cut that one and add another, not cut it and use it.


Yep, see that now, my bad sorry.

Chris


----------



## chenley (Feb 20, 2007)

Bkessler said:


> If you think a second one will be tough to drive in put it at a sharp angle.


Not sure if it's the POCO here or an NEC requirement, don't have my book on hand :whistling2:. If the ground rod is put at an angle it has to be 45 - 90 degrees.



raider1 said:


> Also, did the ground rod meet the 25 Ohm requirement of 250.56? If not you need a second rod anyway.
> Chris


Funny that you say that Raider. Got a call from a client who told me to call the POCO about her meter. Ends up that the meter they are putting on won't work since the ground system doesn't meet the 25 Ohm requirement. It's an 80 year old house so I'll be sinking a couple rods there this Friday.


----------



## Golden Arc (Apr 28, 2008)

Did you try the cup of water trick? Also whats the code on laying it down in a ditch I seen people do it before and say it was ok but i was skeptical.


----------



## bobelectric (Feb 24, 2007)

How are you banging them in? With a good demo hammer?


----------



## raider1 (Jan 22, 2007)

Tim Crimson said:


> Did you try the cup of water trick? Also whats the code on laying it down in a ditch I seen people do it before and say it was ok but i was skeptical.


Here is what the 2008 NEC says about installing ground rods:

250.53(G) Rod and Pipe Electrodes. The electrode shall be installed such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) except that, where rock bottom is encountered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, *where rock bottom is encountered at an angle up to 45 degrees, the electrode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep.* The upper end of the electrode shall be flush with or below ground level unless the aboveground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10.

Chris


----------



## raider1 (Jan 22, 2007)

chenley said:


> Funny that you say that Raider. Got a call from a client who told me to call the POCO about her meter. Ends up that the meter they are putting on won't work since the ground system doesn't meet the 25 Ohm requirement. It's an 80 year old house so I'll be sinking a couple rods there this Friday.


Thats interesting, what happens if you install a second rod and you still don't get 25 Ohms?

Chris


----------



## raider1 (Jan 22, 2007)

bobelectric said:


> How are you banging them in? With a good demo hammer?


I always try to use a hammer drill with a ground rod bit.

Chris


----------



## threewire (Jan 28, 2008)




----------



## threewire (Jan 28, 2008)

Got it this time.


----------



## JohnJ0906 (Jan 22, 2007)

chenley said:


> Funny that you say that Raider. Got a call from a client who told me to call the POCO about her meter. Ends up that the meter they are putting on won't work since the ground system doesn't meet the 25 Ohm requirement. It's an 80 year old house so I'll be sinking a couple rods there this Friday.


What kind of meter requires a connection to earth to function?


----------



## Stickboy1375 (Jul 23, 2007)

JohnJ0906 said:


> What kind of meter requires a connection to earth to function?


And what does the earth accomplish? sounds fishy if you ask me...


----------



## jbfan (Jan 22, 2007)

raider1 said:


> I always try to use a hammer drill with a ground rod bit.
> 
> Chris


That is what I am using, and of course the good old sledge hammer.

What is the cup of water trick?

I guess I'm driving another tomorrow.


----------



## chenley (Feb 20, 2007)

Stickboy1375 said:


> And what does the earth accomplish? sounds fishy if you ask me...


No idea, POCO is meeting me up there to put the meter on after I get the ground rods driven. He hasn't said anything about having to replace the meterbase, hopefully I don't need to. 

I'll get some information from him about it.


----------



## chenley (Feb 20, 2007)

raider1 said:


> Thats interesting, what happens if you install a second rod and you still don't get 25 Ohms?
> 
> Chris


The earth stops spinning on it's axis and I go home :jester:. I'm positive it does not need to be exactly 25 ohms.


----------



## Jim Port (Oct 1, 2007)

raider1 said:


> Thats interesting, what happens if you install a second rod and you still don't get 25 Ohms?
> 
> Chris


Nothing, you have satisfied the Code requirements. The Code does not require that you continue to drive additional rods until you get to 25 ohms or less.


----------



## raider1 (Jan 22, 2007)

Jim Port said:


> Nothing, you have satisfied the Code requirements. The Code does not require that you continue to drive additional rods until you get to 25 ohms or less.


I understand that, I was responding to the statement that the meter required a ground resistance of 25 ohms to work.

Chris


----------



## waco (Dec 10, 2007)

My only comment is that the code wants eight feet of rod "in contact" with the earth. Rod that hits rock isn't in contact with the earth and driving it deeper isn't going to improve the situation.

I admit, I have cut ground rods, but never more than a couple of feet and only when they are the secondary.

If a Bosch hammer drill won't move it, it isn't going to move.


----------



## brian john (Mar 11, 2007)

> If a Bosch hammer drill won't move it, it isn't going to move.


That is not true, I drove one for a sub-panel for my swimming pool it went down 3' and then stopped I left the Hilti on and went to do some other work when I returned I noticed the rod was moving SLOWLY, about 20 minutes later the tip appeared. *I bent the rod and it came out.*


----------



## bobelectric (Feb 24, 2007)

About 25 years ago,I had two men drive a rod in for a job. They told me it came back up 3 feet over.Seeing is believing


----------



## chenley (Feb 20, 2007)

Did that meterbase job this morning and here it is:









The ground was reading 104 ohms beforehand, sunk my two ground rods and attached them to the meterbase ground and it is reading 14 ohms. This is something new our POCO is putting on meters ONLY with the owners request. 
It's a Tesco, residential surge protection, TES 240MSA
http://www.tesco-online.com/products/se/TES240MSA.htm


----------



## bobelectric (Feb 24, 2007)

I would say,the power company meant the Surge arrestor wouldn't be effective with ground resistance that is over 25 ohms. They probably lease that unit with some sort of insurance against surge/lighting damage.


----------



## chenley (Feb 20, 2007)

bobelectric said:


> I would say,the power company meant the Surge arrestor wouldn't be effective with ground resistance that is over 25 ohms. They probably lease that unit with some sort of insurance against surge/lighting damage.


Just got a letter with my bill today. They are calling it "Surge Block" which they will "replace any items lost if the equipment fails to do it's job". They do require the customer sign up for their "power pack" which is cable, internet and voip through them. Could just be creative marketing :laughing:.


----------



## yankeewired (Jul 3, 2008)

*New ground rod driver*

I saw this tool on display at my local supply house. Has anyone tried it yet ? www.sluggo-ox.com


----------



## Stickboy1375 (Jul 23, 2007)

yankeewired said:


> I saw this tool on display at my local supply house. Has anyone tried it yet ? www.sluggo-ox.com


I've had a similar tool for years, POCO guy gave it to me after watching me drive a rod for about 10 mins...  If you bust a lot of sledge handles then its a must.


----------



## surfbh (Jun 1, 2008)

I've used a very heavy piece of pipe, probably 40 lbs with a end cap and rebar handles welded on the sides. Works better than a sledge and sometimes better than a hilti


----------



## Kletis (Jan 18, 2008)

Tim Crimson said:


> Did you try the cup of water trick? Also whats the code on laying it down in a ditch I seen people do it before and say it was ok but i was skeptical.


 
Alright I bite...what's the cup of water trick Tim?


----------



## jbfan (Jan 22, 2007)

Update on the ground rod. Move 6 feet away to drive another one. Installed at Drove it down to, you guess it, 6.5 feet, and this was after a several rain storms.
So I did what any electrician would do. Cut it off, cinnected the two and hooked into the panel.

Customer later told me that they had to blast to build his basement!


----------



## 220/221 (Sep 25, 2007)

I'd use the sawsall to drive that last 18" in. :whistling2:


----------



## MNservicetech (Jun 7, 2008)

Kletis said:


> Alright I bite...what's the cup of water trick Tim?


I'm guessing its pouring a cup of water over a ground rod driven in the ground so you can pass the 25Ω test. Kinda cheating the test, but personally I think ground rods are overrated anyways. They may help for lightning protection, but as far as electric shock, bonding is FAR more important.


----------



## jbfan (Jan 22, 2007)

220/221 said:


> I'd use the sawsall to drive that last 18" in. :whistling2:


 
Were you watching me??


----------



## Kletis (Jan 18, 2008)

MNservicetech said:


> I'm guessing its pouring a cup of water over a ground rod driven in the ground so you can pass the 25Ω test. Kinda cheating the test, but personally I think ground rods are overrated anyways. They may help for lightning protection, but as far as electric shock, bonding is FAR more important.


 
Aaaahhhh that makes sense...Bonding is much more important I agree. Having everything at one potential is very important but whether or not it is the same potential as the earth is really only important if lightning strikes.


----------

