ground electrode

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enteng14 said:
still the AHJ has this power and authority to implement above the code for public safety.
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That is rarely true, if ever.

That is like saying police chiefs can make up laws as they see fit.
 
enteng14 said:
Where in the code states that you are not compliance if you only have one ground rod as grounding electrode? I believe the code only require the additional ground rod for more than 25 ohms measured resistance on the single ground rod.
As what sir infinity said that two ground rod is the simplest grounding electrode system but it doesn't mean that a single ground rod is a violation in the code. Two ground rod is better than one because of combined lower resistance.
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If you don't test the ground rod you can not say it has 25 ohm's or less, That would make a single rod a non compliant installation.
 
enteng14 said:
Where in the code states that you are not compliance if you only have one ground rod as grounding electrode? I believe the code only require the additional ground rod for more than 25 ohms measured resistance on the single ground rod.

As what sir infinity said that two ground rod is the simplest grounding electrode system but it doesn't mean that a single ground rod is a violation in the code. Two ground rod is better than one because of combined lower resistance.
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That may be the case, but when you've driven the second rod how do you KNOW that you are below 25 Ohms? How about the third? The fourth? ...and so on.

How about if we are to measure the resistance today, in SE Texas where it has been raining for 3-4days? I guaran-damn-tee ya that it will be better than 25 Ohms, but how about when the Texas gumbo dries out in three weeks? Will it be still 25 Ohms?

It's just to show ya how silly the Code can get sometimes and people who are arguing it, with it.:grin:
 
enteng14 said:
What would be the size of the GEC for single ground rod as grounding electrode and for two ground rod installation? Also, what is the size of the jumper between the two ground rods?
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#6, #6, and #6.
 
acrwc10 said:
If you don't test the ground rod you can not say it has 25 ohm's or less, That would make a single rod a non compliant installation.
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I disagree (if only to be counted among the people who, as Weressl pointed out, are just being silly by arguing such things :D ). That is not what the code says.

If a single rod has a resistance under 25 ohms, it is code compliant. If a single rod has a resistance over 25 ohms, it is not code compliant. If I do not measure the resistance of a single rod, then I do not know whether the installation is code compliant or not. To simply say that it is not compliant is saying more than can be known.

This is one place in which the AHJ can throw around some weight. The AHJ can place the burden of proof upon the installer. The AHJ can declare that, "Not knowing whether this is compliant is not an acceptable situation. Either prove it is compliant as-installed, or make the compliance beyond question." That is the reason that it is good advice to simply install the second rod and be done with it.
 
charlie b said:
I disagree (if only to be counted among the people who, as Weressl pointed out, are just being silly by arguing such things :D ). That is not what the code says.

If a single rod has a resistance under 25 ohms, it is code compliant. If a single rod has a resistance over 25 ohms, it is not code compliant. If I do not measure the resistance of a single rod, then I do not know whether the installation is code compliant or not. To simply say that it is not compliant is saying more than can be known.

This is one place in which the AHJ can throw around some weight. The AHJ can place the burden of proof upon the installer. The AHJ can declare that, "Not knowing whether this is compliant is not an acceptable situation. Either prove it is compliant as-installed, or make the compliance beyond question." That is the reason that it is good advice to simply install the second rod and be done with it.
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The horse died ,..yet we continue to beat
 
I'm not near a code book but doesn't the code call for a backup or supplimental ground?

The second rod would be needed to comply with the required supplemental ground even if you where below the 25 ohm resistance.
 
ronaldrc said:
I'm not near a code book but doesn't the code call for a backup or supplimental ground?
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If you only have a metal water pipe as the electrode for a service you are required to back that up with at least one other electrode of your choice.
 
charlie b said:
I disagree (if only to be counted among the people who, as Weressl pointed out, are just being silly by arguing such things :D ). That is not what the code says.

If a single rod has a resistance under 25 ohms, it is code compliant. If a single rod has a resistance over 25 ohms, it is not code compliant. If I do not measure the resistance of a single rod, then I do not know whether the installation is code compliant or not. To simply say that it is not compliant is saying more than can be known.

This is one place in which the AHJ can throw around some weight. The AHJ can place the burden of proof upon the installer. The AHJ can declare that, "Not knowing whether this is compliant is not an acceptable situation. Either prove it is compliant as-installed, or make the compliance beyond question." That is the reason that it is good advice to simply install the second rod and be done with it.
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Charlie,

I agree and disagree.
I agree that the Code compliance is undeterminable without testing, but it is true to both the installer and the AHJ. Neither can determine it without testing or the installer can investigate nerby installations that were previously approved and if he can only find single rods then his installation likely to be in compliance since soil coditions in the nearby area show no variance from the area of his installation.
Again I fault the Code of not being clear enough in guidance how to resolve this and pits two parties against each other, each of which is trying to do their job.
Unless of course we argue that when a rod is driven, its resistance should be measured in the presence of the AHJ.
I think it remains the AHJ's responsibility to show that it is not in compliance. House inspectors routinely carry various instruments with them to establish various parameters and request remedy based on those. HVAC for example.
I just don't like it when it is always the installer who is on the loosing end of the deal....
 
ronaldrc said:
Is it just water lines Bob?
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Yes, I don't know why.

If you built a house with no metal water main and no 1/2" or larger steel in the footing you could get by with just one ground rod if it showed less then 25 ohms.
 
Laszlo has a good point. Unless the inspector can show the GES is not in compliance, than it is in compliance.

There is no requirement that anyone test for 25 Ohms. therefore, if the inspector believes it is not 25 Ohms, it is up to him to show that it is not, unless there is some kind of local amendment to the contrary.

IMO, it would be wise for the CMP responsible for this badly written paragraph to come up with some kind of alternate that eliminates the 25 Ohm thing altogether. Why doesn't every other GE have to make 25 Ohms? What is so different about a rod pounded into the ground?
 
I am at a loss, I have no idea why it would be the AHJs job to prove it does not meet the requirement.

The installer must use a rod that complies with the NEC, one of those requirements is to achieve 25 ohms on one rod or choose another way to comply.

In the real world it is up to the EC to prove the rod has 25 ohms or less. I also am one of the many that simply installs two rods and walks away.
 
infinity said:
Article 250 requires that the rod have a resistance of 25 ohms or less or it must be augmented by another rod or electrode. If you don't want to actually test the single rod you'll need to install a second one.
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How will anyone KNOW without testing, if the second rod installation fulfilled the Code's 25 Ohm requirement?
 
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