Stray Voltage

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Voltage Potential Pos. & Neg. must balance

Voltage Potential Pos. & Neg. must balance

Well good points made but i think most grounding issues are made by not testing your ground rods meaning it must be less than 5 ohms or lower and not the 25 ohms per nec thats not good enough i dont like the nec its not enough ! I think most electrical work done the ground rods installed are not enough meaning not done correctly one rod is not enough ? And when it comes to shocking a farm animal with stray voltage the animal can not take the voltage a person can . They do not let go as we would react to a shock of electricity so they hang on longer and die they dont know there getting shocked . But in our trade today the grounding is not done or tested correctly its done and never tested again one rod is not good !!one test is not enough!!! all voltage potential returns to earth .Iam not a electrical engineer but a balance must be between points of potential when a level of potential is present which will conduct to the nearest point to equal that potential of charge . Tesla said it think about it ? earth is a conductor it will pass a current and a voltage can be measured from dirt earth to any point so if a engineer cant answer this were did he go to school ? best to ya
 
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until the utilities can be convinced that using the earth as a return path for ground faults (the reason for this use of the neutral) is a bad idea, then "stray" current will never go away. (imshio) (the alternative would be to add a separate grounding conductor everywhere and this seems to be too much to bear, and would also still not preclude the use of earth since some lightning protection is taken into consideration in the current design)
 
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floating voltage high voltage low side issue ?

floating voltage high voltage low side issue ?

Well without the earth to neutral path what would happen if you did not connect it to earth you would have a bigger issue like what if your transformer went bad meaning the windings shorted to case or any line to metal structure the path of least resistance would take it . Or just say no ground rods then any point is a point of return meaning not just metal but us . A wye to wye transformer would rise in voltage floating up or down with load on secondary side high voltage can be present here bad news . a delta wye transformer what if a line dropped or a short between secondary and primary happen ? high voltage is now present on low side ? paths thur windings could happen like a load could passing thru a phase to b phase lots of issues think about that ?comments Thats why they ground it .
 
The article makes a good case for isolating neutrals. Seems one sided, though.

I've seen how country folks wire things up, so I'm not sure that the article's main point of blaming the utility as the source of most "stray voltage" is correct. I would think more animal deaths result from jake-leg electrical installs than from utility neutrals. Perhaps some GFCI protection is in order.
 
It is Donald Zipse , and I agree ,. He has an outside the box kind of way at looking at things ,.. and he has written some great substantiations to the various CMPs
 
ronaldrc is a senior member here, so I hope that he chimes in. I don't know if he wrote that article, or if he simply has a copy of it on his web page.

I don't have any direct experience with stray voltage, but have read about it in different articles written with different viewpoints. Some points to consider:

1) Improper wiring at the dairy itself can also cause stray voltage. Others can quibble about the relative proportion of utility versus facility cause of stray voltage, but if you are investigating a stray voltage problem you must check out the facility wiring, looking for improper ground-neutral bonds and the like.

2) The multi-earth-neutral system probably improves system reliability and safety with respect to lightning, even as it introduces stray voltage issues. These issues must be balanced. IMHO eliminating the MEN system is probably a bad idea.

3) The utility should probably be doing a better job of balancing primary side loading in order to reduce neutral current flow and neutral voltage rise.

-Jon
 
ohmhead said:
Well good points made but i think most grounding issues are made by not testing your ground rods meaning it must be less than 5 ohms or lower and not the 25
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Interesting points.
Is there a standard that requires the resistance to be 5 ohms or less?
Whats the advantage of 5 ohms or less?
What section in the the NEC requires 25 ohms?
 
ohmhead said:
Well good points made but i think most grounding issues are made by not testing your ground rods meaning it must be less than 5 ohms or lower and not the 25 ohms per nec thats not good enough i dont like the nec its not enough !
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Can you point to any factual basis for your view?
 
We have never checked ohms on a ground rod. Maybe I should start doing this. How do I test it?
We have always just sunk a 5/8" dia ground rod and run a #6 bare from it to the point in the meter can.
 
aftershock said:
We have never checked ohms on a ground rod. Maybe I should start doing this. How do I test it?
We have always just sunk a 5/8" dia ground rod and run a #6 bare from it to the point in the meter can.
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You could drive a thousand rods and you won't get 25 ohms or less.

If you do get 25 Ohms during a test. Test the same rod(s) a week later

and you won't have 25 ohms anymore. I've done four, three point tests

and I've never seen 25 ohms or less on a ground rod.
 
Vibroground

Vibroground

Well we test with old three point tester called a vibroground its a reed tester its better than the new clamp on testers . Most jobs we do the electrical engineer specs this type of tester ,also we must get per engineers request a 5 ohm or less resistance test on one rod . We also install a delta of 3 rods 40 foot down each cad welded rods 5/8 copper clad and attach a 3/0 copper cad welded gec we also have these rods 30 foot apart in a delta arrangement to each other rod . we test each rod one at a time then we test the whole complete system when finished . We get less than one ohm every time and must have a engineer witness the test with inspector on site . we do this on every job . My reason for 5 ohms or less is what i have been doing for years and on every job its required ? comments ?best to ya
 
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ohmhead said:
Well we test with old three point tester called a vibroground its a reed tester its better than the new clamp on testers . Most jobs we do the electrical engineer specs this type of tester ,also we must get per engineers request a 5 ohm or less resistance test on one rod . We also install a delta of 3 rods 40 foot down each cad welded rods 5/8 copper clad and attach a 3/0 copper cad welded gec we also have these rods 30 foot apart in a delta arrangement to each other rod . we test each rod one at a time then we test the whole complete system when finished . We get less than one ohm every time and must have a engineer witness the test with inspector on site . we do this on every job . My reason for 5 ohms or less is what i have been doing for years and on every job its required ? comments ?best to ya
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What are the soil conditions where you achieve 1 ohm? Just curious.

I've done tests in clay and could'nt achieve 1 ohm. Then again that

was in 80's. Our meters were'nt as sophisticated as they are today.
 
ohmhead said:
Well we test with old three point tester called a vibroground its a reed tester its better than the new clamp on testers . Most jobs we do the electrical engineer specs this type of tester ,also we must get per engineers request a 5 ohm or less resistance test on one rod . We also install a delta of 3 rods 40 foot down each cad welded rods 5/8 copper clad and attach a 3/0 copper cad welded gec we also have these rods 30 foot apart in a delta arrangement to each other rod . we test each rod one at a time then we test the whole complete system when finished . We get less than one ohm every time and must have a engineer witness the test with inspector on site . we do this on every job . My reason for 5 ohms or less is what i have been doing for years and on every job its required ? comments ?best to ya
Click to expand...

Karl H said:
What are the soil conditions where you achieve 1 ohm? Just curious.

I've done tests in clay and could'nt achieve 1 ohm. Then again that

was in 80's. Our meters were'nt as sophisticated as they are today.
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It is funny to me that many people think the lower the better on the OHM reading of the ground rod, Don't forget if you get the reading to low your neutral current may have a less resistive path on the ground rod then on the neutral wire running straight from the service lateral. This would cause more current on the ground then on the service laterals neutral wire, how safe is that?
 
ohmhead said:
Well good points made but i think most grounding issues are made by not testing your ground rods meaning it must be less than 5 ohms or lower and not the 25 ohms per nec thats not good enough i dont like the nec its not enough
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Well I am one of those telecom engineers that specify 5 ohm grounds, and it has nothing to do with stray voltage. In fact the lower the ground electrode impedance is, the higher your stray voltages will be because of more current flow via earth. Further the NEC does not require a 25 ohm ground period.

Ask 10 telecom or data center engineers why a 5 ohm earth ground is needed, and 9 of them will not have a clue and will say it is because that is what we always do. The 1 engineer who knows something about it will tell you so we have a planned GES and not left to the discretion of the EC by driving two ground rods and call it a day. He might further add it is to minimize inductance of a single or dual ground rod in contact with earth and improve ground saturation during a direct lightning strike to the facility.
 
touch voltage

touch voltage

Well we disagree with the comments on the 25 ohms . Read article 250.56 a single electrode consisting of a rod pipe or plate that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode ect ect . Also yes most engineers cant explain because they think a electrician is not able to understand , but were not talking data or tele comm my work is industrial ,power plants or commercial large projects with high specs . our ground earth is nothing special just sand ,clay mixed , type c soil mostly but we go down deep some of our rods go to 60 foot it depends on resistance of test . when you drive multi rods it easy to get low resistance . Touch voltage on the towers ground resistance for the tower would have to be less than one ohm it has to do with voltage from live line to earth distance . someone told me that once .comments best to ya
 
ohmhead said:
Well we disagree with the comments on the 25 ohms . Read article 250.56 a single electrode consisting of a rod pipe or plate that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode ect ect .
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And once you add one rod your done even if the reading is 100 ohms

Or if your just using a single concrete encased electrode there is no requirement at all.

It is just not important to the electrodes ability to do what it is intended to do.


I strongly suggest you don't close your mind to new thoughts without so much as giving them a chance based only on 'we have always done it this way' or 'this was what I was told a long time ago'.
 
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