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  1. #1
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    Default Stray Voltage or Fish Story?

    Joe Nernberg posted this on another site.

    Mystery at Topaz substation

    Sounds a bit fishy to me. My understanding is that voltage is measured as a differential against ground. If the system was properly grounded and bonded, there should be no "stray voltage". I'm probably missing something here. But as Joe remarked in the other post, "what is a health care real estate professional"? What else is incorrect in that article?

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  2. #2
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    Default Re: Stray Voltage or Fish Story?

    Voltage is measured as a differential between two points. If one point was at 1000 volts and the other was at 1120 all the meter would see would be the 120 volt difference.

    All answers based on unamended National Electrical codes.

  3. #3
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    Default Re: Stray Voltage or Fish Story?

    Well, I read the article and I'm on the side of the "fish" story.

    Lightning is stray voltage. Static Electricity is stray voltage.

    If the problems are as severe as they say they are, I would have started back at the water pipe and verified that no one had come along and replaced a section of metal pipe with PVC and failed to install a Bonding Jumper to both sides of the metal pipe.

    I have seen this happen at least 3 times. A quick simple test was to just clip a copper wire to the pipe sections and the problems went away.

    Also, there is this statement from the article, "One of the men allegedly told her that a cow can withstand 500 ohms of current whereas a human can take 1,000 ohms. Wilson was flabbergasted."

    I had no idea that we are now measuring current in Ohms, did you?


  4. #4
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    Default Re: Stray Voltage or Fish Story?

    Quote Originally Posted by Donald Farrell View Post
    Well, I read the article and I'm on the side of the "fish" story.

    Lightning is stray voltage. Static Electricity is stray voltage.
    Stray voltage is a real thing to be concerned with, no "fish story" there.

    The problem, in large part, comes from the power companies not using 4-wire laterals or overhead drops. The neutral is bonded to ground at the service equipment, and it is at the service equipment where the service is tied to earth.

    That mean that the neutral current is trying to get back to its source via: a) the neutral conductor; b) earth.

    And, as we all know, electricity does not take the path of least resistance ... it doesn't, trust me ... it takes *ALL* paths, and *ALL* paths means not only through the neutral, but through earth to the source transformer ground, through earth to a different transformer ground and back to the source transformer through the common neutral conductor and ground all around, etc.

    Also, there is this statement from the article, "One of the men allegedly told her that a cow can withstand 500 ohms of current whereas a human can take 1,000 ohms. Wilson was flabbergasted."

    I had no idea that we are now measuring current in Ohms, did you?
    That's because the technical people were not writing the story, writers were, and they probably wrote what she told them as she thought she heard it.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  5. #5
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    Default Re: Stray Voltage or Fish Story?

    G,

    Note the article makes no distinction as to the type or wave form of the electrical charges or voltages measured.

    Further note the indication was that the original homes were as built with absolutely no interconnection to the gas utility supply system - this is key. Additionally, that the troubles originated after the homes were sold and gas service was installed. It is telling that the utility has not been able to supply the home in question with "residential" type service.

    The location and proximity regarding the pipeline path, and this being the apparent "reasoning" behind the history of development is furthermore telling.

    Proximity to pipeline, parallel or crossing point at substation, particulars regarding utility visits especially revisiting when sandy soil was wetted is also telling.

    Special attention regarding the soil conditions. "Normal" grounding, safe and/or containment systems esp. for clearing faults at substations oftentimes do not work in such soil conditions. Our armed forces experienced this first hand overseas with electrified shower facilities in IRAQ and Afg. a la "contractors.

    Cathodic protection systems for gas pipelines can be compromised, and same can be excellent unintentional conductors.

    The article does not expand on any covenants or deed restrictions which may have been imposed prior to first transfer to private owner.

    As far as "heath care real estate professional" This simply indicates that the party focuses or specializes on real estate utilized in the business of health care. A super specialized commercial type occupancy. It does not indicate the party is engaged in the sale or lease activities of same, but it could include such activities. The management of, etc. could also be included, as could the intricate web of approvals, specialized planning, specialized health care occupancy design for systems management, construction, retrofitting, density zoning, licensing, etc.

    Although not a technical rendition by any means, it is merely an "interest" type news story format.

    I find nothing in same which you linked to to indicate any thing other than that. Did not find the vaguely referenced but not sourced or linked "discussion".

    FYI and for your reading enjoyment, is an investigation checklist from another source regarding similar "investigations" for remediation.

    Generally, the specifics regarding power distribution are now considered not only utility-proprietary, but matters of national security. We know nothing about the geo-technical examinations, studies, etc. at the location, extra encased systems, etc. which may have been employed. We further do not have a detail regarding what else may be present on the subject home's property. There has been no mention of an engineering study of any discipline acquired at the subject property.

    Multiple "source" at a substation.


    I would not be surprised if the mater is "resolved" or "settled" with the particular homeowner already or will soon be, in theory, if she has a savy attorney who has engaged and acquired the services of a properly disciplined firm to conduct the appropriate investigations studies. Although finalizing the dollar amounts, etc. for the various types of injury/torts, etc. may take years; and would expect such would be under seal or "gag" from some point forward as a condition.

    An example of how one might approach:

    Clickable link: Copyright Safe Engineering Services

    Last edited by H.G. Watson, Sr.; 10-15-2011 at 08:50 AM.

  6. #6
    Join Date
    Mar 2009
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    601

    Default Re: Stray Voltage or Fish Story?

    Watson's rantings aside, the fact is that if the voltages present are high enough and the house is close enough there may not be anything that can be done about the charged metal stuff in the house.

    If the sub-station has voltages in the 250KV or higher range there is a significant radius where voltage is induced in almost anything metal that is high enough to be felt, and can be significant if a ferrous metal.

    At one point in my career I built a couple of traffic signals at an interchange that was also crossed by a 350KV transmission line on one side and a 500KV on the other. The fact some of the parts were under the lines required engineering assistance from the utility to assure minimum clearances for the voltages involved. All the steel parts at these intersections gave a mild to nasty kick when touched, and some of these parts were steel poles buried in 12 feet of concrete, and the others were bolted to a footing with a 16 foot deep re-bar cage buried in concrete and bonded to the bolts supporting the poles. - couldn't have been grounded better. You could not touch the tops pf these poles without insulating gloves on, and you could still feel a good tickle at the bottom of them. Even the green posts with reflectors that were driven in the ground here along the road edge would tickle a remarkable distance from the lines. You definitely didn't want to be carrying a steel key ring in pants pockets on these jobs. Even the nails we used for the concrete forms felt a bit funny.

    Given similar voltages it's entirely possible that a completely isolated shower head not even hooked to any plumbing could become charged enough to shock, and one where someone was wet would only compound the problem.

    All this coupled with the fact some people have a much more sensitive sense touch than others can prove very problematic. However, given the severity of the "shocks" around the intersections I'm a bit curious how anyone could stand to hold on to the shower head very long, or why they would.

    The point is that in the vicinity of a sub station with very high voltages everything can be done right and you can still have induced voltage on metal items in close proximity and have no issues at all with things not being grounded right.


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