Supplemental rod required even with 9 Ohms Resistance?

[sfav8r]

I just busted an inspection today due to only one ground rod (in addition to water pipe).

I explained to the inspector that the resistance was 9 ohms and proceeded to show him my handy clamp on ground rod tester.

Much to my chagrin, he said "it doesn't matter what your meter says, you need a second ground rod."

His bottom line...Your meter has no validity. Get a 3rd party verification and a letter from that company or put in an additional rod."

I don't see any reference to this in NEC or the local amendments.

Any help is appreciated.

Thanks.

 

[tx2step]

Re: Supplemental rod required even with 9 Ohms Resistance?

If you are testing the ground rod correctly, then I believe that you are right and he is wrong.

I don't know of any NEC requirement that you must get a 3rd party verification.

But I rarely find it worthwhile to get into a conflict with an AHJ unless the issue is significant.

To me, adding one ground rod wouldn't be a significant issue, unless you are talking about having to do it on a number of buildings.

Good inspectors are open minded and fair. Fortunately, most fall into that catagory.

On the other hand, I've found that "petty" inspectors tend to have long memories and can be vindictive.

 

[paul]

Re: Supplemental rod required even with 9 Ohms Resistance?

I'm having a difficult time with one ground rod having only 9 ohms resistance.

 

[hurk27]

Re: Supplemental rod required even with 9 Ohms Resistance?

I have always thought that when enforcing a law it is up to the enforcement agency to prove that you are breaking the law in the first place?

Am I off base on this?

 

[apauling]

Re: Supplemental rod required even with 9 Ohms Resistance?

Although this was a pet peeve of mine, it no longer is. It isn't that i changed my mind or had some new insight into the NEC. This is a mess. There are no rules for what qualifies the 3rd party, there are no rules for what qualifies the measurement. There are no rules for interpreting this specific measurement. In fact no one can come with why it's 25 ohms. There are some theories and assertions, but no actual answers. But it might as well be written in the HOLY BOOk, whichever one it is, and you better believe that the inspector has the divine inspiration to know what it means, because no one wants to do anything with or about it, and it's written in such a way that the AHJ can claim what they want.

you might want to fight it, but coming up with a world peace and universal health care would be easier. In fact one of them will probably happen before that piece of the NEC is cleaned up.

paul

 

[luke warmwater]

Re: Supplemental rod required even with 9 Ohms Resistance?

Wayne, I was sitting here thinking the exact same thing. (except for the high bumper part).

If one rod doesn't get us to 25 ohm or below, we must drive a second rod as per 250.56.
So, we must measure to know if we must install another, right?

But, if we only have one installed, wouldn't the burden of proof fall on the inspector as to the actual resistance, for him/her to fail the installation? ie. take his/her own reading.

If this is the case, I would think it to be important to actually know the resistance first, otherwise, drive the second rod.

One area that we work in has an ammendment that requires (2) rods, regardless. I guess they know from taking readings around the area that (1) rod wouldn't get to 25 ohms, so they require (2).

Another said adding a second has done absolutely nothing, so we don't require the second one.

 

[physis]

Re: Supplemental rod required even with 9 Ohms Resistance?

It sounds like your inspector is saying that you're in violation because in his opinion the resistance to ground hasn't been established.

So the question is:

Is their a legally adopted method for making the measurement that will have to be followed?

If there's not, I think the building department has to accept your measurement. Unless they make one of their own that disagrees.

Even if they really do have to accept your measurement their probably used to getting their way (two ground rods) because so many EC's just put in the second rod rather than argue about it. Which is why I advocate standing up to them. They'll probably just continue to hassle people until somebody does.

There's no reason you should have to put in a second ground rod if you can correctly make the measurement.

 

[wirenut1980]

Re: Supplemental rod required even with 9 Ohms Resistance?

originally posted by apauling

you might want to fight it, but coming up with a world peace and universal health care would be easier. In fact one of them will probably happen before that piece of the NEC is cleaned up.

hahahahahahahhahahaha!

To the original poster, the $100 it will cost you to drive a second ground rod will more than pay for itself when compared to the time and headaches you will have in convincing this yahoo that they are wrong, and that is if they are wrong. If the inspector winds up being correct, or simply will not budge, then you will have to drive the extra rod anyways. Let the baby have its bottle. It is easy for us on this forum to say, "go ahead and fight it! put that A-hole in his place!" but when it comes down to it, I know I personally would not put too much time and effort into something of this nature.

 

[paul]

Re: Supplemental rod required even with 9 Ohms Resistance?

In WA some years ago, the state went around and tested the resistance of ground rods all over the state. They found that none came even close to the 25 ohms. They then added the following to our state rules:


(2) If a ground resistance test is not performed to ensure a resistance to ground of twenty-five ohms or less, two or more electrodes as specified in NEC 250.52 must be installed a minimum of six feet apart. However, a temporary construction service is not required to have more than one made electrode.

So...do you pay for the test or just drive two rods? Answer is easy, drive two rods in and call it good. This is really not a section of the code that's worth getting into a pissing match with an inspector, IMHO.

 

[charlie b]

Re: Supplemental rod required even with 9 Ohms Resistance?

What 250.56 says is that a single rod that ?does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode . . . . ? The inspector is clearly wrong here. I don?t think anyone has yet said anything that disagrees with this statement. Furthermore, I agree with physis:

Originally posted by physis: I think the building department has to accept your measurement. Unless they make one of their own that disagrees.

It is regrettable that the most sensible action is to drive a second rod, just to get the inspector off your back. But keep in mind the words of Yoda, Jedi Master: taking the quick and easy path leads to the dark side of the force.

 

[sfav8r]

Re: Supplemental rod required even with 9 Ohms Resistance?

Interesting replies. Thank you.

I agree 100% that in general this is a non issue (time to install vs. time to argue). In this case, the 6' spacing rule becomes a hassle.

Concrete is a minimum of 6", there is no exposed soil on the property (San Francisco) except for the rear yard behind the patio near the rear property line and there are various gas/water pipes that I have no idea where they are. On a side note, the inspector said "It's a 5/8 rod being driven straight down, do you really think your going to hit a pipe?" I thought that was an interesting question from someone who professes that he is adamant on the ground rod because it is a safety issue."

At any rate, for me, the issue is not just this one job. Many locations in San Francisco can be difficult to put two rods in and while this is not insurmountable by any stretch, I resent having to "just put in another one" when there is nothing gained by doing so.

The clamp on on ground rod testers make incredibly accurate measurements possible in literally seconds. Mine also has a calibration grid that you measure before any test and clearly shows before each measurement that the instrument is reading correctly. I just don't see why this isn't acceptable to the inspector.

FYI - I was also surprised by the 9 ohms. It is the lowest reading I have seen since I purchased the meter about 6 months ago. 50 ohms is much more common and 100 is not unheard of. I would guess that about 30% of the rods test 25 or below.

Another interesting thing I have found since using the meter is that dayd to day measurements can vary significantly on the same installation.

I requested a meeting with the head honcho (first time in 11 years). I'll let you know how it goes.

Thanks again for the input.

[ June 29, 2005, 01:16 PM: Message edited by: sfav8r ]

 

[tx2step]

Re: Supplemental rod required even with 9 Ohms Resistance?

Originally posted by charlie b:
It is regrettable that the most sensible action is to drive a second rod, just to get the inspector off your back. But keep in mind the words of Yoda, Jedi Master: taking the quick and easy path leads to the dark side of the force.

Charlie -- I agree with your sentiments, but in this case I guess You'd have to call me Darth Vader.

I try to pick my battles. This isn't one I'd choose to fight. Too little to gain and too much to loose.

Unless there's more to the story or more history with this AHJ than was presented, then I'd keep my ammo dry and save it for the big issues.

Edited to add the following:

sfav8r -- I was writing a response to Charlie's thought when you were posting.

Now that I understand your situation better, I can certainly understand why you are pushing this issue. It is worth fighting in your case. I hope you win your case (I expect that you will).

Also, I recommend that you watch your backside in the future if you will have more dealings with this particular inspector. Guys like you describe don't like to be proven wrong -- and can be vindictive.

[ June 29, 2005, 01:33 PM: Message edited by: tx2step ]

 

[physis]

Re: Supplemental rod required even with 9 Ohms Resistance?

I thought San Francisco was going to or has adopted an amendment to mandate two rods.

I'm glad I don't do work there. Those inspectors can really suck. You can go broke and all your hair turn grey arguing with those guys too. They'd probably force the issue to go to court just cause they can and that's the kind of people they are.

 

[hurk27]

Re: Supplemental rod required even with 9 Ohms Resistance?

By Sam: They'd probably force the issue to go to court just cause they can and that's the kind of people they are.

And I'll win!

I said the above statement because in the past I have done some studying of law (I didn't say allot) The question is this how can a law enforcement (this is what a AHJ is) cite for a law yet to be broken. If this law enforcement person has not done the test on a ground rod then he has no ground to stand on (No pun intended ) if ever challenged in court.
This would be like getting a ticket for speeding but the officer never turned on his radar gun.

Officer in court to judge: "I know he was speeding because he look like he was going fast" :roll:

 

[physis]

Re: Supplemental rod required even with 9 Ohms Resistance?

Trouble is that this is civil and at least around here, if you loose you pay all the court costs. Because it's a municipality they get to use a team of lawyers. you don't.

That makes the odds go way way up that you'll loose. And now you'll have to pay for their five attorneys. How much you want to bet they're paid five times more than necessary.

I'll stop now because I'm very close to using very foul language.

Edit: Can you imagine a layman having a better understanding of the NEC than you?

Put that slipper on the other foot with a lawyer! And the kabillions of code books they use.

[ June 29, 2005, 08:09 PM: Message edited by: physis ]

 

[sandsnow]

Re: Supplemental rod required even with 9 Ohms Resistance?

I would have signed you off.

 

[sfav8r]

Re: Supplemental rod required even with 9 Ohms Resistance?

Originally posted by sfav8r:
Interesting replies. Thank you.

I requested a meeting with the head honcho (first time in 11 years). I'll let you know how it goes.

Thanks again for the input.

Well, the meeting was informative...in a very frustrating sort of way. The bottom line is this:

AS we all previously discussed, 250.56 sets the standard at 25 ohms. The San Francisco Amendments do not address or alter this section, so it is exactly the same as the NEC.

At some point, the question was raised by one or more inspectors, "well, how do we verify the ground rod resistance?"

The city had several options to choose from.

1) Trust the EC to test and properly report the resistance.

2) Provide a means of testing for all of the inspectors.

3) Make it mandatory to have a 3rd party verification an all installations.

4) Require EITHER 2 rods or a 3rd party verification.

SF opted as a POLICY to initiate option four. I concede that they have a legitimate concern here. I do have two problems with their answer though.

First, there is absolutely no reason that the "Policy" cannot be adjusted to allow for demonstration of 25 ohms or less by the EC at the time of inspection. They could require that the meter be up and ready to demonstrate at the time of inspection. In the case of my meter this takes about 15 seconds.

The meter comes with a test grid that you clamp onto and is marked off in ohms (.0472 ohms, 10 ohms, 47.2 ohms, and 100 ohms), therefore, one can easily verify proper operation very quickly.

The BIG problem I have, is that there is no effort by the city to publish the policy and distribute it to ECs in the area so they'll know what to expect. Let me restate that more accurately...There is no effort by the city to distribute this information to non-union contractors. It turns out that the city does send this information to the local union so they can inform their guys ahead of time!

I questioned (with all the diplomacy I could muster) the equity in this. The city's position is that the union is a single point of contact for a number of contractors and it is a very efficient way of getting the word out.

I suggested that their web site would be an efficient way to distribute this information and offers the advantage of informing ANY interested contractors, not just the union guys. He agreed, but didn't even know if the information is there or if there were plans to put it there.

On the upside, when I mentioned that SF is still on the 99 NEC and this is 2005 and I have never had this problem before he gave me the most honest answer I have ever received from the city. "A lot of our inspectors think its BS and they just don't bother with it."

I requested and received a copy of the district map where the original inspector works. I will still bid jobs there but will adjust my bids with the knowledge that I can count on at least two inspections, 2 ground rods, the gas pipe cannot be bonded at the hot water heater, plastic cover plates are not acceptable in the garage if it is not sheet rocked...

 

[allenwayne]

Re: Supplemental rod required even with 9 Ohms Resistance?

When you have your ducks lined up straight and have NEC articles to back your situation I have no problem with calling in the chief inspector.I have done so on many occasions,when the violations that are used are not applicable or clear in the context thay are written.
A few months ago I met with an inspector the 2 years ago was breaking my we private parts and driving me nuts.He failed 11 finals in one day citing 1/4 in set back on panel covers.So we went and removed the drwall amd corner bead from these panels and called for reinspects .He again failed all 11 finals.I called the chief and showed him the problem and he told me that he had told his inspectors if factory screws would not be long enough to fail the final due to 1/4 in rule.There hadbeen several cases where th EC had used 2 in screws and penetrated conductors .He told me to recall all 11 and he would have a talk with this inspector.6 months later he showed up on the job and shook my hand and appokigized for being so over zealous.I was in shock.Since then we have had no problems he calls me on minor violations tells me what to do and signs them off but when there is a bona fied corection he will write it up as he should.
Moral of the story don`t be afraid to stand up to an inspector but know you are right brfore you do

 

[rcbutcher]

Re: Supplemental rod required even with 9 Ohms Resistance?

Did the 9 ohm reading occur with the rod and water pipe both bonded to the grounding electrode system when the measurement was taken?

 

[Jerimi]

Re: Supplemental rod required even with 9 Ohms Resistance?

But keep in mind the words of Yoda, Jedi Master: taking the quick and easy path leads to the dark side of the force.

Charlie, thanks for the Yoda. We all should listen to YODA more often