Expotential bonding system scenario

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EMO

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Scenario: contractor for a city "splash pad" water feature (kids water fountain) covered work prior to inspection of exponential gound bonding system as called for in 2005 NEC, 680.26 and 680.55. The contractor, not the electrician, did the bonding. No one, other than the contractor can verify what was installed prior to concrete placement. There is 50 volts at the control panel fed from a stepdown transformer approximately 120' away. Control panel operates the timing mechanism and water spray features. The service is grounded at the stepdown transformer location (fed by a 30 amp CB). All water supply and drain piping is PVC. There are metal fittings for poles and spray features on the pad and there is a rebar grid within the concrete deck.
Need advice on how to get the contractor to assume liability for their work (no state licensed electrician performed the work) to protect the public and city. How can you verify that the expotential bonding system is 1) intact and bonded to all metal within the deck area, and 2) what resistance reading is acceptable for the expotential bonding system. I know that 25 ohms is acceptable for the grounding system, but what is proper for the expotential bonding system?
They have offered to provide test reports from a lightening protection firm specializing in grounding, but I need to know what the report should specifically say. I know this is a lot to ask for, but I believe I've come to the right place to help me in this matter. Thank you in advance.
 
Is the 50 Volts suppose to be there, is this control voltage, phantom voltage from improper meter readings/understanding/misuse or is it stray voltage.

There are several test that can be performed.

The two point test is basically a continuity test, problem is if there is any metallic connection the reading will most likely be low <1 ohm. Will not prove or disprove the existance of any supplemental ground system.

A three point test will measure the resistance to earth/ground (if performed properly) of any electrode system, if you can isolate the system, but as you describe the system, this isolation is not feasible? If you accept this method, require a detailed testing spec from the testing contractor or better yet SUPPLY a TESTING SPECs that must be adhered too, including recent calabration of any test equipment.

So to me the question is, was there a specification? Was inspection required? What is your part in this? What about the 50 Volts?

http://www.aemc.com/techinfo/techworkbooks/ground_resistance_testers/950-WKBK-GROUND-WEB.pdf

http://www.transcat.com/images/Gnd_Testing_FAQ.pdf
 
Brian John,
50 volts supplies the controllers for the water feature sprays; yes it is supposed to be there. Specifications (reviewed plans) were submitted at time of permit issuance. The contractor speced the expotential bonding grid along with four driven rods beneath the splash pad deck. They have provided pictures of various portions of the job, but this does not substitute the actual inspection and hands on of checking tightness of bonding clamps or wire guage, etc. They were told in two meetings when an inspection was to be called for, but they neglected to do so. Short of popping it up and starting over, I would like to search for alternate methods of ensuring the job was done right.
My part in this is to protect the public from a potentially unsafe situation due to no inspection being performed prior to covering up the work. If there is a published accepted testing spec, can you point me in the right direction? I'd appreciate it.
 
EMO,

They were told twice, they ignored it, it was not even an Electrician that

did it, start the chipping hammers boys this is not a game!!!
 
benaround said:
EMO,

They were told twice, they ignored it, it was not even an Electrician that

did it, start the chipping hammers boys this is not a game!!!
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As an inspector, if I had to tell people more than once to provide for an inspection, and then I am told that the work is complete, I would think very strongly that "hanky panky" is the name of the game they are playing. Because pool grounding is so important for safety, it would be easy for me to ask for proof positive for the grounding info necessary...hence I would want to see the conductors in place.
 
There is 50 volts at the control panel fed from a stepdown transformer approximately 120' away. Control panel operates the timing mechanism and water spray features. The service is grounded at the stepdown transformer location (fed by a 30 amp CB). All water supply and drain piping is PVC.
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None of this is relevant IMO.

There are metal fittings for poles and spray features on the pad and there is a rebar grid within the concrete deck.
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If there is a rebar grid in the concrete deck, was this inspected by the local concrete inspector? The normal metal ties used are sufficient means of bonding the rebar together if tied correctly. The concrete inspector would have verified that. It may be a simple matter of opening up the concrete and tieing into the rebar, then tieing all the metal parts together above grade.

Need advice on how to get the contractor to assume liability for their work (no state licensed electrician performed the work) to protect the public and city.
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Also not relevant. By doing the work, the contractor assumed liability for it. Licenses, permits, and inspections are not relevant to the liability issue. The city owns the structure so they are the ones primarily liable. No amount of licenses, permits, or inspections removes the city's liability.

How can you verify that the expotential bonding system is 1) intact and bonded to all metal within the deck area, and 2) what resistance reading is acceptable for the expotential bonding system. I know that 25 ohms is acceptable for the grounding system, but what is proper for the expotential bonding system?
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25 Ohms has nothing to do with this situation, as it is not a grounding electrode installation.

They have offered to provide test reports from a lightening protection firm specializing in grounding, but I need to know what the report should specifically say. I know this is a lot to ask for, but I believe I've come to the right place to help me in this matter.
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The lightening protection firm does not have a time machine.

I doubt there is a test procedure that will prove that the thing was done according to code. If an inspection was required, it should have been done before the thing was buttoned up. Short of a time machine, you cannot undo what was done.

Why do I suspect there is more to this story than is being told?

Who's the winner that had them put in four ground rods? Thats an interesting part of the story.
 
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Sounds like you need to hire a third party that knows what to do. I assume there are motors in connections with this slide feature. The motors need to be bonded to the Equipotential bonding grid. Has this been done??? This is very dangerous and I strongly advise help from an outside party that is knowledgeable about this. Ground rods are not part of the requirements for equipotential bonding.
 
In the area where I work, there was a serious accident that resulted in a man getting seriously injured, which will be with him till he dies.

The lawsuit generated is $157,000,000.00. All parties are being sued, including the inspection company.
The worst part is most people are fixated on the $$$ part of the suit, when they should really think of how to reduce these types of accidents from ruining families lives forever.
 
Pierre C Belarge said:
The worst part is most people are fixated on the $$$ part of the suit, when they should really think of how to reduce these types of accidents from ruining families lives forever.
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I can't agree more. Too much fixation on $, not enough on safety.
 
Dennis Alwon said:
Sounds like you need to hire a third party that knows what to do. I assume there are motors in connections with this slide feature. The motors need to be bonded to the Equipotential bonding grid. Has this been done??? This is very dangerous and I strongly advise help from an outside party that is knowledgeable about this. Ground rods are not part of the requirements for equipotential bonding.
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"Very dangerous" may be overstating things by quite a bit. These kind of installations are all over the place and the vast majority of them have no formal equipotential grid, and it is not as if people are droping dead left and right.
 
Petersonra, you wrote
"If there is a rebar grid in the concrete deck, was this inspected by the local concrete inspector? The normal metal ties used are sufficient means of bonding the rebar together if tied correctly. The concrete inspector would have verified that. It may be a simple matter of opening up the concrete and tieing into the rebar, then tieing all the metal parts together above grade."

There was no concrete inspection prior to placement. And there are no motors as street (water) pressure is what makes the water features work. Solenoids (low voltage) operate each water feature.

I can't predict the future, but stray current has been known to show up in the funniest places (manhole covers, street grates, marinas, pools, etc.). I believe that when the NEC asks us to provide a safety feature, we, as inspectors, should ensure that those features are there. The contractor circumvented the process and I am searching alternate ways to verify the expotential bonding system. As a last resort, they may have to tear it up and start over again at their cost.

Thanks for your input.
 
EMO said:
I can't predict the future, but stray current has been known to show up in the funniest places (manhole covers, street grates, marinas, pools, etc.). I believe that when the NEC asks us to provide a safety feature, we, as inspectors, should ensure that those features are there. The contractor circumvented the process and I am searching alternate ways to verify the expotential bonding system. As a last resort, they may have to tear it up and start over again at their cost.

Thanks for your input.
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Most of what people term as "Stray voltage", such as I have bolded in your post is not "stray voltage", it is fault current.
 
EMO
You mentioned they have four ground rods connected to the re-bar and buried in the concrete. This ex-potential grid must of been designed by some engineering firm and they would have the specs on it. The next question would be whether or not the contractor cut short cuts. I would take him to court and tie him to the installation for a longer period of time and not release his bond. This would tie up some cash flow and help to ensure he complies next time he bids a job. If you tear it up and it is good you might find yourself on the other end of legal proceedings for part of the cost especially if fountain is up and running. The legal system is funny like that.
 
cschmid said:
EMO
You mentioned they have four ground rods connected to the re-bar and buried in the concrete. This ex-potential grid must of been designed by some engineering firm and they would have the specs on it. The next question would be whether or not the contractor cut short cuts. I would take him to court and tie him to the installation for a longer period of time and not release his bond. This would tie up some cash flow and help to ensure he complies next time he bids a job. If you tear it up and it is good you might find yourself on the other end of legal proceedings for part of the cost especially if fountain is up and running. The legal system is funny like that.
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I am not so sure that you are correct on this one. In reality, it is not up to the inspector to do anything. It is the owner's problem and the owner has to deal with it some way. The inspector should just fail the project because it cannot be properly inspected and than stay out of it, as it is none of his business. At that point it is between the owner and the contractor, as it should be. The inspector is not a party to the contract in any way shape or form and should not be involved in trying to resolve the situation.
 
Pay a 3rd party engineer to accept responcibility. if none will, (they will for the right amount of money), then it must be exposed at all locations and inspected.
 
EMO said:
They were told in two meetings when an inspection was to be called for, but they neglected to do so.
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Their contract most likely spells this out as well. As such, the terms of the contract have not been adhered to. E.G, default, chop up the areas required for inspection, or do it over. Let the choice be theirs.
 
you are correct... as an inspector he should just fail it and move on. I took it he was a city inspector and it was a city job. I also assumed it was up and running already. I assumed a couple of things and I can not do that thank you for pointing that out.
 
cshmid and petersonra have made some excellent points about fail it, move on and let the city and contractor battle it out. I hope it will be that easy, but somehow the inspector ends up the bad guy because it doesn't pass. I originally asked that the state licensed electrician provide an affidavit on company letterhead stating they complied with the NEC and perform a resistance test to ground and provide the results and test criteria. Little did I know that the electrician did not do the work, the contractor did and then covered it up. The electrician provided the CB, UGE and GFCI up to the cabinet that houses the manifold and valves controlling the splash pad. Each station is operated by a low voltage solenoid with a timing device and manually operated staions. Just so you'll know, the electricians work passed.
Now I'm being asked by the city what other options are available to the contractor so they can pass, like I should be able to provide alternate ways of verifying the expotential bonding system. I'm not new to inspecting, but I don't know everything either. If there is a way, I'd like to know about it.
 
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