additional ground rod?

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acrwc10

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
I changed a 100a meter panel from fuses to main breaker.I drove a 5/8'' grnd rod at the service location,there was an existing main water ground in #6 bare copper,all copper water service from the street. The inspector required a second ground rod be installed"min. 6' from the first rod". I politely quetioned why we needed a second rod if we had an all copper water service.His reply was "if you have it tested by a third party testing service he would accept that it." I felt this was weak, but a second ground rod is cheap and the inspector needs to come back afew more times for other reasons.The job is 40 miles from my house and my van gets bad gas milage.
My question is does this make any sense to you guys. By the way the ground rod is about 5' above sea leval and very close to the ocean. You chould get 25 ohms with a piece of string the ground is so conductive here.
 
250.53(D)(2) requires a supplemental electrode that must comply with 250.56. It may be the practice and policy of your local jurisdiction to just simply require the 2 ground rods...

You may be able to object to the second rod if you can prove the 25-ohm ground resistance, but it may not be worth it in the long run.
 
acrwc10 said:
By the way the ground rod is about 5' above sea leval and very close to the ocean. You chould get 25 ohms with a piece of string the ground is so conductive here.
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Really? What about at low tide? Here there's so much sand the soil is not conductive unless its wet. The other problem here is there's so much salt in the soil that the ground rods don't seem to last... I was helping buld a deck the other day when a guy tripped on the ground rod... it broke off about a foot deep... but at least its really easy to drive the new ones in.
 
at low tide the ground still remains wet. the testing of the gounding ,fine, I have a tester that will do a three point fall of potencial.Experiance tells me that this area is perfectly fine, I don't believe the NEC requires me to prove through third patry testing that it is less then 25 ohms. A second rod is cheap to comply will what the inspedtor wants.I just don't like inspectors asking for things that are not needed,it is not comming out of thier pocket.This is wrong ,cheap compliance does not mean it should be done.This same building dept. wants the electrician on the job to due a final inspection.Once again "why" if the GC is there and there was nothing wrong at rough in what is going to change at final, the only thing they are looking at is gfic outlets and cover plates.Is it really nessary for my to be there.I think not. If they ask me "is that circuit gfi protected" and I say yes that doesn't mean you should not do your job and check that it is.If someone was to lye about it that doesn't mean it is, so why ask the question,check it.If you check it, you dont need me to be there to ask the question to.Pass it or fail it just inspect it. I did my job they should do thiers. To often I see inspectors not doing what they should and letting things slide by that should be called and fixed.Most recently we had a house inspected and the inspector didn't even look in half the house.That is not an inspection,But I am not going to drag him in and start pointing things out that he missed about plumbing and framing.My question is still do I really need a third party test? Or should I just do unnessary work to please someone who holds the pen?
 
acrwc10

By the way the ground rod is about 5' above sea leval and very close to the ocean. You chould get 25 ohms with a piece of string the ground is so conductive here.
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The above quote an assumption,

If they ask me "is that circuit gfi protected" and I say yes that doesn't mean you should not do your job and check that it is
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and you didn't want the inspector making assumptions


I just don't like inspectors asking for things that are not needed,it is not comming out of thier pocket.
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i have witnessed inspectors requiring items that they would have done differently but are not necessarily code required. the easiest way to verify the requirement is to ask for a code reference. in our municipality it is required for the inspector to substanciate the demand with a reference.

I politely quetioned why we needed a second rod if we had an all copper water service
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Did you read the code citation from BPH. Your answer to 250.53 (D)(2) forces you to comply with 250.56.

My question is still do I really need a third party test?
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that is not up to the NEC but to the AHJ and or your local laws and regulations.
your inspector needs to be able to prove to others that your installation was acceptable. he can do this through methods handed down to him from the local legislative bodies. usually either witnessing the test, getting documentation from 3rd parties (ie an engineer) or other ways the local codes give him to meet his burden of proof. He or his superiors should be able to tell you what methods he can accept. if you disagree with him, look up the rules your self. the more you know the more easily it is to comply, which saves time.

btw, this may have been a better question for the grounding and bonding forum
 
The requirement for third party test is xxxx That would cost as much as 10 ground rods.

If you apply 120 VAC through a light bulb to limit current, you should be able to measure amps with your clamp-on and volts with your voltmeter. Even an electrical inspector who can't pass the journeyman test should be able to see that Volts/Amps is resistance and if is less than 25 Ohms, you should need only one rod.
 
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The requirement for third party test is xxxx That would cost as much as 10 ground rods.
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That is why most people simply install the 2nd ground round. then there is no disputing the system meets code. if someone does dispute it you can argue with a code book over the phone instead of a tester in person.

you pay the inspectors enough with your permit fee that they can "test" the gfci's for proper performance, but i doudt that your permit fee is expensive enough to cover the inspector "testing" the ground rods for <25, when it's so simple for you to simly drive a 2nd rod.

if you really want to argue it, then set up the test when the inspector can witness it or get a "legally bound" 3rd party agency to verify results and submit those in writing.

This is common sense folks
 
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Bob NH said:
The requirement for third party test is xxxx That would cost as much as 10 ground rods.

If you apply 120 VAC through a light bulb to limit current, you should be able to measure amps with your clamp-on and volts with your voltmeter. Even an electrical inspector who can't pass the journeyman test should be able to see that Volts/Amps is resistance and if is less than 25 Ohms, you should need only one rod.
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Apply 120 volts to what??? I hope you aren't suggesting that someone connect a hot wire to the ground rod to see how much current flows!! That sounds dangerous!!
 
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If I clear the area around the ground rod and apply 120 volts through a 100 watt bulb, through an insulated wire connected to the ground rod, by pressing a momentary switch while I measure voltage relative to the grounded conductor and current through the insulated wire, it is not dangerous except to earthworms and grubs.
 
Bob NH said:
it is not dangerous except to earthworms and grubs.
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Regardless we can not recommend doing that here.

There are proper testers on the market for grounding electrode testing.


Besides, it never helps if you electrocute the inspector
 
acrwc10 said:
This same building dept. wants the electrician on the job to due a final inspection.Once again "why" if the GC is there ...
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For two reasons:
1 - to answer any questions the AHJ might have. YOU have the responsility for a complaint installation - NOT the GC.

2 - it's a sign of respect and confidence in your work...as opposed to disrespect and attitude towards "authority".

Have you locked horns with this AHJ before?

acrwc10 said:
My question is still do I really need a third party test? Or should I just do unnessary work to please someone who holds the pen?
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You should do what makes you feel warm and fuzzy at the end of the day (and complies with 250.56)...and maybe fix the van.
 
steve66 said:
Apply 120 volts to what??? I hope you aren't suggesting that someone connect a hot wire to the ground rod to see how much current flows!! That sounds dangerous!!
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I've done it. What happens? Nothing. Connect the conductor going to the rod to a 20 amp breaker and read the current flow with an ammeter. If you had 12 ohms the meter will read 10 amps. 6 ohms reads 20 amps.
 
acrwc10,

What state are you located in? If it is NJ you are required to have two.

new to the forum guy's and thought I'd chime in.
 
DMW said:
new to the forum guy's and thought I'd chime in.
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Welcome "new guy" :D
(You really want to be called "DMV" and be from NJ...LOL, now that's funny!)

DMW said:
acrwc10,

What state are you located in? If it is NJ you are required to have two.
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Do the other states not follow 250.56?
 
celtic said:
Have you locked horns with this AHJ before?

You should do what makes you feel warm and fuzzy at the end of the day (and complies with 250.56)...and maybe fix the van.
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No I don't get into battles with inspectors, it would be really a waist of time. I wanted to throw this out to you and see what the concencess was.

I agree two rods is a cheap way to make them happy, and the AHJ has never failed to pass a job of mine in this city "drive a second rod "took less time then the conversation.

Now my van took your comment very personally and is sulking in the driveway, It is a ford and they have very fradgile egos.:)
 
DMW said:
acrwc10,

What state are you located in? If it is NJ you are required to have two.

new to the forum guy's and thought I'd chime in.
Click to expand...


That is correct for installations under the 2002 and 2005 NEC. I performed this test in my own house which has only one. I think that my totally inaccurate method gave me a resistance of about 40 ohms. By the way, welcome to the forum.
 
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