# Ground rods



## Crack Wireman (Aug 22, 2014)

On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


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## Dennis Alwon (May 9, 2009)

Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


If you can prove 25 ohms on 1 rod you are good otherwise you need 2


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## Crack Wireman (Aug 22, 2014)

Dennis Alwon said:


> If you can prove 25 ohms on 1 rod you are good otherwise you need 2


I've read that Dennis, however 250.53a says you need 2 electrodes. The water pipe is one, and 1 rod is the second.


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## Dennis Alwon (May 9, 2009)

Here are the articles



> 250.3(D)(2) Supplemental Electrode Required. A metal underground
> water pipe shall be supplemented by an additional
> electrode of a type specified in 250.52(A)(2) through
> (A)(8). If the supplemental electrode is of the rod, pipe, or
> ...





> 250.53(A)(2) Supplemental Electrode Required. A single rod, pipe,
> or plate electrode shall be supplemented by an additional
> electrode of a type specified in 250.52(A)(2) through
> (A)(8). The supplemental electrode shall be permitted to be
> ...


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## Dennis Alwon (May 9, 2009)

It clearly states you have to supplement the water pipe. If the supplement is a rod then you must do it as stated in 250.53(A)(2) which says 1 rod at 25 ohms or drive 2 rods & go home


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## Crack Wireman (Aug 22, 2014)

Right. The water pipe needs to be supplemented by one electrode. The 25 ohms is an exception. That's the way I read it. 

Anybody else read it the way I do?


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## Crack Wireman (Aug 22, 2014)

If a single electrode (water pipe) is 25ohms them you don't need the supplemental (rods).


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## Crack Wireman (Aug 22, 2014)

I hope guys read the article and chime in, bc I really don't think 2 rods are necessary. The 25 ohms has to do with the first electrode, if you don't have the 25 ohms then you need the supplemental electrode (rod). 

Not trying to argue Dennis, I just don't think it's a clear cut article


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## Wirenuting (Sep 12, 2010)

Dennis Alwon said:


> It clearly states you have to supplement the water pipe. If the supplement is a rod then you must do it as stated in 250.53(A)(2) which says 1 rod at 25 ohms or drive 2 rods & go home


The first is required and the second one is free, then it's the Mc-coffee drive thru.


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## Crack Wireman (Aug 22, 2014)

Wirenuting said:


> The first is required and the second one is free, then it's the Mc-coffee drive thru.


You agree with my interpretation?


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## Wirenuting (Sep 12, 2010)

Crack Wireman said:


> You agree with my interpretation?


I read it as 1 rod and if you don't have 25, drive a second and call it a day.


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## don_resqcapt19 (Jul 18, 2010)

The water pipe always has to be supplemented by an additional grounding electrode.
A single rod that does not meet the 25 ohm rule is not a grounding electrode.


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## Crack Wireman (Aug 22, 2014)

don_resqcapt19 said:


> The water pipe always has to be supplemented by an additional grounding electrode.
> A single rod that does not meet the 25 ohm rule is not a grounding electrode.


Not sure how you got that out of the article Dennus posted


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## electricmanscott (Feb 11, 2010)

Crack Wireman said:


> I hope guys read the article and chime in, bc I really don't think 2 rods are necessary. The 25 ohms has to do with the first electrode, if you don't have the 25 ohms then you need the supplemental electrode (rod).
> 
> Not trying to argue Dennis, I just don't think it's a clear cut article


The 25 ohms has nothing to do with the water pipe. The water pipe, when used as an electrode has to be supplemented by another electrode. If that supplemental electrode is a single ground rod it must meet the 25 ohm requirement. If it does not you must add another. 

It's pretty clear cut and it's been around for a while.


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## FlyingSparks (Dec 10, 2012)

Also check with your utility, some require two rods off the bat.


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## Crack Wireman (Aug 22, 2014)

FlyingSparks said:


> Also check with your utility, some require two rods off the bat.


I drove 2, but when I showed the inspector the article, "he said, I was taught you have to drive 2. I'm requiring 2."


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## Crack Wireman (Aug 22, 2014)

electricmanscott said:


> The 25 ohms has nothing to do with the water pipe. The water pipe, when used as an electrode has to be supplemented by another electrode. If that supplemental electrode is a single ground rod it must meet the 25 ohm requirement. If it does not you must add another.
> 
> It's pretty clear cut and it's been around for a while.


Its not really that clear cut. I asked 3 other guys at the supply house and I had 1 agree with me. He's a master electrician and been doing this his whole life like me


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## wildleg (Apr 12, 2009)

Crack Wireman said:


> I drove 2, but when I showed the inspector the article, "he said, I was taught you have to drive 2. I'm requiring 2."


and that, my friend, is the heart of the problem.

I respect your attempt at reading what it says, but I think you are doomed to put it 2 rods.


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## Bad Electrician (May 20, 2014)

Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


If you hit the underground water pipe won't you have a wet basement?:laughing:


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## Crack Wireman (Aug 22, 2014)

bad electrician said:


> if you hit the underground water pipe won't you have a wet basement?:laughing:


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## Crack Wireman (Aug 22, 2014)

wildleg said:


> and that, my friend, is the heart of the problem.
> 
> I respect your attempt at reading what it says, but I think you are doomed to put it 2 rods.


I completely agree. No where in that article does it clearly state anything. 
I asked the inspector, what he hoped the 2nd ground rod would accomplish???? I got a very dumb and puzzled look in return


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## Bad Electrician (May 20, 2014)

Crack Wireman said:


> Its not really that clear cut. I asked 3 other guys at the supply house and I had 1 agree with me. He's a* master electrician* and been doing this his whole life like me


Not all masters are that masterful, having that license is not always the Holy Grail of electrical knowledge.


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## Crack Wireman (Aug 22, 2014)

Bad Electrician said:


> Not all masters are that masterful, having that license is not always the Holy Grail of electrical knowledge.


I definitely agree with that! I am a journeyman. I know that I don't know everything and I don't pretend to. That article can very easily go in either direction as far as I'm concerned. I only ever drive one rod and never had a problem before today


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## Big John (May 23, 2010)

Bad Electrician said:


> If you hit the underground water pipe won't you have a wet basement?:laughing:


 Nuts. I came here to make the same joke.


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## Crack Wireman (Aug 22, 2014)

The exception clearly states if one rod,PIPE(water pipe) or plate meets the 25 ohm requirement NO SUPPLEMENTS ARE REQUIRED. It doesn't say anything about driving in more ground rods


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## Awg-Dawg (Jan 23, 2007)

Crack Wireman said:


> The exception clearly states if one rod,PIPE(water pipe) or plate meets the 25 ohm requirement NO SUPPLEMENTS ARE REQUIRED. It doesn't say anything about driving in more ground rods


 You need to keep reading the section.

* (D) Metal UndergroundWater Pipe.​*​​​​If used as a grounding​
electrode, metal underground water pipe shall meet the​ requirements of 250.53(D)(1) and (D)(2).​* (1) Continuity.​*​​​​Continuity of the grounding path or the​
bonding connection to interior piping shall not rely on water​ meters or filtering devices and similar equipment.​* (2) Supplemental Electrode Required.​*​​​​A metal underground​
water pipe shall be supplemented by an additional​ electrode of a type specified in 250.52(A)(2) through​ (A)(8). If the supplemental electrode is of the rod, pipe, or​ plate type, it shall comply with 250.53(A). The supplemental​ electrode shall be bonded to one of the following:​ (1) Grounding electrode conductor​ (2) Grounded service-entrance conductor​ (3) Nonflexible grounded service raceway​ (4) Any grounded service enclosure


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## Crack Wireman (Aug 22, 2014)

Awg-Dawg said:


> You need to keep reading the section.
> 
> (D) Metal UndergroundWater Pipe. If used as a grounding
> electrode, metal underground water pipe shall meet the
> ...


Read it a 1000 times. It shall be supplemented. Then read the EXCEPTION that contains the 25 ohms part. The EXCEPTION is the key. You need a supplement EXCEPT if you have your 25ohms


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## Awg-Dawg (Jan 23, 2007)

Crack Wireman said:


> The exception clearly states if one rod,PIPE(water pipe) or plate meets the 25 ohm requirement NO SUPPLEMENTS ARE REQUIRED. It doesn't say anything about driving in more ground rods


I think you are confusing Pipe and Water pipe, they are two different electrodes. (At least as how the NEC sees them.)


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## wildleg (Apr 12, 2009)

if you feel strongly about it - then put in a suggestion to the code panel to clarify the language. Believe me, I'm all for that. As an aside, 2 ground rods shouldn't be breaking the bank.


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## Crack Wireman (Aug 22, 2014)

Awg-Dawg said:


> I think you are confusing Pipe and Water pipe, they are two different electrodes. (At least as how the NEC sees them.)


Perhaps, nobody here really changed my mind about the article. There's nothing clear cut about it. Saying that its been that way for a long time isn't really supportive of any evidence. 
What if you drive 2 and don't have 25ohms. Do you drive another? 
Also if you drive ten rods and tie them together you still only have one electrode


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## Crack Wireman (Aug 22, 2014)

wildleg said:


> well, I gotta say, despite all your teeth knashing, you have to admit that two ground rods are better than one, and if that is breaking the bank then it's time to do somethin else. Also, if you feel strongly about it - then put in a suggestion to the code panel to clarify the language. Believe me, I'm all for that.


Wild leg it had nothing to do with the money. We make our fair share. It has to do with just buying into somethinghe because people believe it to be. The inspector today was a former GC that did his own wiring (no license in PA)when he was in biz and he really think bc he read 1 and 2 family dwellings and passed the test he is this great electrical mind. And he simply isn't. That's what its about. So when he got cocky and said you need 2 rods, I said show me in the book. He couldn't


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## Crack Wireman (Aug 22, 2014)

On a side note, he can't pass plan review or the general electrical.


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## kg7879 (Feb 3, 2014)

If you are reading the 2014 code it states for a metal underground water pipe that a supplemental electrode is required. 

The supplemental electrode can be any of the electrodes listed 250.52 A(2) through A(8). If the supplemental electrode is of rod, pipe, or plate type then you must add an additional rod, pipe, or plate.

The exception is not for the metal underground pipe but for supplemental electrode.

I believe the reason behind adding additional ground rod is a lot of houses will have their underground water pipe changed out eventually to pvc and nobody wants to test for 25 ohms of resistance.

If the house did not have any other electrodes present at the house then you would have to drive two ground rods or two pipes or two plates. (or measure for 25 ohms or less on the single ground rod, pipe, or plate)


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## don_resqcapt19 (Jul 18, 2010)

Crack Wireman said:


> The exception clearly states if one rod,PIPE(water pipe) or plate meets the 25 ohm requirement NO SUPPLEMENTS ARE REQUIRED. It doesn't say anything about driving in more ground rods


The pipe in that exception is not a metal under ground water pipe. It is a length of pipe or conduit that has been driven in the ground just like you drive a ground rod. The use of the terms pipe and metal underground water pipe are not interchangeable.

That was the common grounding electrode in my are when I started, and the grounding electrode conductor was 1/2" rigid conduit connected to the driven 3/4" pipe with a wedge clamp. The other end of the 1/2" was connected to a "service entrance el" (an LB with a tapped 1/2 conduit entry on the bottom) or it was run to the meter can and terminated with a pair of locknuts. There was no copper grounding electrode conductor of the wire type in this installation


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## Crack Wireman (Aug 22, 2014)

Well I really respect a lot of the opinions on here, I've learned quite a deal on this forum. My interpretation must be wrong. Thanks for clearing it up for me guys


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## RIVETER (Sep 26, 2009)

Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


The more the better...six feet apart. Mandatory...maybe not, but safer.:thumbsup:


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## cavie (Sep 12, 2014)

Crack Wireman said:


> I hope guys read the article and chime in, bc I really don't think 2 rods are necessary. The 25 ohms has to do with the first electrode, if you don't have the 25 ohms then you need the supplemental electrode (rod).
> 
> Not trying to argue Dennis, I just don't think it's a clear cut article


 Dennis knows of what he speaks. Do you really ant to get into a pissin' match with an inspector if he want's to see 25 ohms on one rod?? Drive another $6.00 ground rod 6' away and go home. 

Master Electrician 
Electric Inspector


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## zen (Jun 15, 2009)

This is a good thread although confusing.. we bond service bonding bushing from panel H 1 to bldg steel based on feeders. Then # 6 to ground rod. .likewise where there are multiple disconnects. Havent been failed. But now im wondering what suplements which ground. The rod plus bldg steel or bldg steel plus the rod. I dont mes with cold water. Usually too far from the service. Ground rod is outside bldg steel is right there or straight up

Sent from my SPH-D710BST using electriciantalk.com mobile app


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## don_resqcapt19 (Jul 18, 2010)

zen said:


> This is a good thread although confusing.. we bond service bonding bushing from panel H 1 to bldg steel based on feeders. Then # 6 to ground rod. .likewise where there are multiple disconnects. Havent been failed. But now im wondering what suplements which ground. The rod plus bldg steel or bldg steel plus the rod. I dont mes with cold water. Usually too far from the service. Ground rod is outside bldg steel is right there or straight up
> 
> Sent from my SPH-D710BST using electriciantalk.com mobile app


Only the water pipe requires a supplemental grounding electrode.

You don't have any choice about using the metal underground water pipe as a grounding electrode if there is one at the building. It is a required electrode. See 250.50.

If you have building steel that qualifies for use as a grounding electrode or if you have a concrete encased electrode, there is no need to install ground rods per the rules in the NEC.

If you have a metal underground water pipe along with building steel that qualifies as a grounding electrode or a concrete encased electrode, there is no requirement to install ground rods.

Note that my comments are per the rules as found in the NEC. Some utility companies require ground rods no matter what other electrodes exist.


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## zen (Jun 15, 2009)

Ty sir. That was very helpfull. It could be that here inspector s want 2 out of 3 and I havent seen a problem with which 2 are used. My boss said you never know what they will want from one inspection to the next. He has been failed on bldg steel because he couldnt prove the structural bond to a CEE .for us water is typically a long way from the service.

Sent from my SPH-D710BST using electriciantalk.com mobile app


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## chicken steve (Mar 22, 2011)

don_resqcapt19 said:


> Note that my comments are per the rules as found in the NEC. Some utility companies require ground rods no matter what other electrodes exist.


That's all they focus on here 

~CS~


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## don_resqcapt19 (Jul 18, 2010)

chicken steve said:


> That's all they focus on here
> 
> ~CS~


We told them that is not something that they have the authority to enforce. They agreed that they would not enforce their in the areas that have local inspections.


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## chicken steve (Mar 22, 2011)

That would make sense Don. 

The poco's usually want less responsibility and liability , especially if a state or municipal ahj can take up the slack.

~CS~


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## aaroncnty (Sep 15, 2014)

*why do more work*



Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


there should only be one ground rod required because it is 25 ohms per rod


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## 3xdad (Jan 25, 2011)

cavie said:


> Drive another $6.00 ground rod 6' away and go home.


Damn, i'm gett'n ripped.:blink:


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## Achilles (Sep 11, 2014)

Crack Wireman said:


> Perhaps, nobody here really changed my mind about the article. There's nothing clear cut about it. Saying that its been that way for a long time isn't really supportive of any evidence.
> What if you drive 2 and don't have 25ohms. Do you drive another?
> Also if you drive ten rods and tie them together you still only have one electrode


Yes - I work in Michigan, but I've heard from Arizona of driving 3 ground rods due to soil type.

My experience is just drive two and nobody questions the 25 ohms.


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## Dennis Alwon (May 9, 2009)

Achilles said:


> Yes - I work in Michigan, but I've heard from Arizona of driving 3 ground rods due to soil type.
> 
> My experience is just drive two and nobody questions the 25 ohms.


That is all the code requires. AZ may have an amendment but I have never heard that before


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## Speedy Petey (Jan 10, 2007)

aaroncnty said:


> there should only be one ground rod required because it is 25 ohms per rod


Huh?? What do you mean? 
And where do you find a 25ohm per rod rule?


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## backstay (Feb 3, 2011)

Drive two, get paid, go home.


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## RIVETER (Sep 26, 2009)

Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


Bottom line is that if a plumber has to replace the water line they do not usually worry about grounding of an electrical system. That being the case it is a good idea...and mandatory to drive a rod. It is sometimes hard to achieve the proper resistance to earth that is acceptable with only one supplemental so the best way is to drive another a specific distance away, and just give up.


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## Kaffeene (Feb 11, 2014)

Bad Electrician said:


> If you hit the underground water pipe won't you have a wet basement?:laughing:


This actually happened to a guy I was working with several years ago. 
The ground rod was driven down about 6.5-7 feet and hit the water main for a house.
When the damaged area was exposed it, it was clear through the middle, I think 3/4 or 1" copper piping and butterflied it. 
You would think the odds for that would be 0.15625.


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## FaultCurrent (May 13, 2014)

Some inspectors have asked for additional rods to be driven until the total resistance <25 ohms. I've seen ass many as six. 

Don't believe this is required but some of the School District inspectors want this.
Just sayin'


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## Pete m. (Nov 19, 2011)

FaultCurrent said:


> Some inspectors have asked for additional rods to be driven until the total resistance <25 ohms. I've seen ass many as six.
> 
> Don't believe this is required but some of the School District inspectors want this.
> Just sayin'


I would have to wonder if that's a job spec. It's certainly not what the NEC requires.

Pete


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## Speedy Petey (Jan 10, 2007)

Kaffeene said:


> This actually happened to a guy I was working with several years ago.
> The ground rod was driven down about 6.5-7 feet and hit the water main for a house.
> When the damaged area was exposed it, it was clear through the middle, I think 3/4 or 1" copper piping and butterflied it.
> You would think the odds for that would be 0.15625.


I've seen this myself. :boat:
No, it wasn't me that did it...thankfully.


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## Kaffeene (Feb 11, 2014)

As far as engineering job specs, it's like pulling up to a drive-thru to get food. 
You tell them what you want... and take what you get.


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## 480sparky (Sep 20, 2007)

FaultCurrent said:


> Some inspectors have asked for additional rods to be driven until the total resistance <25 ohms. I've seen ass many as six.
> 
> Don't believe this is required but some of the School District inspectors want this.
> Just sayin'



I'd merrily drive 'ass' many rods as they want. It's their money they're giving to me! :whistling2:


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## Speedy Petey (Jan 10, 2007)

480sparky said:


> I'd merrily drive 'ass' many rods as they want. It's their money they're giving to me! :whistling2:


Thing is, services are mostly contract jobs. If I figure on only driving two rods and someone demands six, it's _"Here are your two. Show me in writing where I need more, or sign that paper."_


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## chicken steve (Mar 22, 2011)

_B-b-b-b_-ut, don't some states actually measure the ~R~ ?


~CS~


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## 480sparky (Sep 20, 2007)

Speedy Petey said:


> Thing is, services are mostly contract jobs. If I figure on only driving two rods and someone demands six, it's _"Here are your two. Show me in writing where I need more, or sign that paper."_



Exactly. NEC states one if I can prove 25 ohms or less, else add another. You want 6? Pay me for four more.


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## sbrn33 (Mar 15, 2007)

As I read it if you have one of the main ones as in water pipe, concrete encased electrode or building steel if you can prove the contact with CEE then you only need one rod. 
If you rely on ground rods for your only source then you need 2.


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## Speedy Petey (Jan 10, 2007)

sbrn33 said:


> As I read it if you have one of the main ones as in water pipe, concrete encased electrode or building steel if you can prove the contact with CEE then you only need one rod.
> If you rely on ground rods for your only source then you need 2.


Not exactly. Even if you rely only on rods you can get away with one if you can prove 25 ohms or less.
If you have a CEE then NO other additional electrodes are required.


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## 1.21gigawatts (Jun 22, 2013)

I picked up an AEMC clamp ground tester last week. Was very suprised to see well over 180 ohms on some existing services. The average was around 75 ohm for older single steel rod. Has anyone had luck using a listed coupling and driving 20' plus to achieve < 25 ohms or meet demanding specs ?


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## RIVETER (Sep 26, 2009)

Crack Wireman said:


> On a service upgrade if you hit the underground water piping system, how many ground rods are required? I have an inspector who makes you drive 2, even though my interpretation is only 1 is required.


Most codes only present the minimum requirements. One extra rod can only make things better, IMO. I would not argue.


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## Kaffeene (Feb 11, 2014)

Basically any grounding electrode that exists needs to be connected to the grounding electrode system. If all you have is the underground water pipe then supplement it with an additional electrode, such as 2 ground rods.

A single ground rod electrode is required to be provided with a supplemental electrode (not counting the underground water pipe), such as, but not limited to, another ground rod, unless the exception can be met in 250.53(A)(2) requiring the ground rod to have a contact resistance to earth of 25 ohms or less.

Most cases, it's just easier to drive the extra ground rod (not less than 6ft. away from the first).


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## FF301 (Jan 12, 2014)

The codes requires 25 ohms or less if not then add a 2nd ground rod regardless of the method or type, The inspector can require you to prove it, so are you going to spend 500 dollars to have it tested or 6 dollars for a 2nd rod ?? Get real- just drive the 2nd rod and go home with your inspection passed and look good to your customers. And by the way- even if you don't have less then 25 ohms you are not required to have any more then 2 rods.


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## Kaffeene (Feb 11, 2014)

Just to add to my previous post, 250.53(D)(2) regarding the metal underground water pipe and requiring a supplemental electrode points over to 250.53(A) when you supplement it with an electrode of the rod type.

If someone was using the ground rods and metal water pipe electrodes, and no other electrodes are present, than treat the ground rods as the sole electrode.

This is because metal water piping can be changed out to plastic pipe at any time and then that electrode is no longer present.


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## chicken steve (Mar 22, 2011)

1.21gigawatts said:


> I picked up an AEMC clamp ground tester last week. Was very suprised to see well over 180 ohms on some existing services. The average was around 75 ohm for older single steel rod. Has anyone had luck using a listed coupling and driving 20' plus to achieve < 25 ohms or meet demanding specs ?


Years ago there was a friendly bet between an EC and the AHJ , just 1/2 hr south of me. They coupled , but kept hitting bedrock never quite achieving the under 25R

2 rods have been pretty much a given since locally....

~CS~


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## MF Dagger (Dec 24, 2007)

FF301 said:


> The inspector can require you to prove it,.


Just out of curiosity, CAN the inspector require you to prove it? It's his job to inspect. If I drive one and find I'm under 25 ohms am I required to prove that somehow?


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## Kaffeene (Feb 11, 2014)

I'm sure the inspector would probably ask someone to prove it in most cases. Even if you did prove it they could still tell you to drive an additional rod if it's practicable. The AHJ has the final approval of the installation.


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