Most of the units I have seen, don’t dump the full current to ground.
Sparks could fly.
Also ground can vary hugely from dry sand to wet soils but if you want to see your ground and its effective value, do Like I did last night.
We have excellent soil values here with metals in the volcanic soil and rock.
Take a power cord, a light bulb, and socket with wires.
Place the return wire from the light to a grounded pole, the pole doesn’t even have to be very long.
Then light up the bulb. [and it is full bright]
Mined only showed a few volts that didnt make it to earth, and no neutral was even present.
That ground pole as long as it’s a foot or longer will work just fine.
You can further make a neutral test that is less efficient, then measure the voltage and its loss, then ground that terminal and everything goes away. [all but a tad]
The sole purpose of the extra ground is not when you don’t need one or that it is the perfect cure to take everything you have, its there to divert mistakes like harmonics that can come from equipment mismatches, poor return neutrals, and many other minor faults.
All of these are heavily listed in the code.
The main thing is that even if it were totally unless in poor soil, it doesn’t harm or risk a thing.
It either picks up the slack or it doesn’t, or just some.
And if your soil is really that bad, bond it to a cement slab as they also suggest.
That works as well but they did stipulate the slab should be at least 2 inches thick.
They also suggest water pipes and all sorts of alternative choices.
Ill end up reading the entire code section on grounds if I haven’t already done so.
As much as they don’t suggest this as an automatic idea for everything, they do list many examples and they also tell you not to go overboard with 500 ground leads all running in different directions because of other obvious reasons.
Strange AC Power Issue
Hello MrAl,
I think that you now understand Robert Reed's point. New Jersey is probably one of the better areas in the country for earth grounds. Most of southern California is desert with the water table well below the surface. Out here, an earth ground is better than nothing, but I wouldn't bet on a very low resistance. I certainly wouldn't want to bet on it for protection from electrical shock.
I think that you now understand Robert Reed's point. New Jersey is probably one of the better areas in the country for earth grounds. Most of southern California is desert with the water table well below the surface. Out here, an earth ground is better than nothing, but I wouldn't bet on a very low resistance. I certainly wouldn't want to bet on it for protection from electrical shock.
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Chris Smith
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- Joined: Tue Dec 04, 2001 1:01 am
- Location: Bieber Ca.
I certainly wouldn't want to bet on it for protection from electrical shock.
That is not even its purpose. Its sole design is to pick up the slack that a neutral didn’t carry fully.
Either a small leak or harmonics caused from such things as a computer PS, or what ever.
In fact, thanks to my dedicated neutral, I don’t get shocked by my computer work from all sorts of computers.
Before the ground,... 50% of all the computers had a small voltage present at the case. We use three standard wires.
Now its always gone.
Our volcanic soil is better than normal, as the bay area has more clay than iron and rock.
But even there it worked just fine.
That is not even its purpose. Its sole design is to pick up the slack that a neutral didn’t carry fully.
Either a small leak or harmonics caused from such things as a computer PS, or what ever.
In fact, thanks to my dedicated neutral, I don’t get shocked by my computer work from all sorts of computers.
Before the ground,... 50% of all the computers had a small voltage present at the case. We use three standard wires.
Now its always gone.
Our volcanic soil is better than normal, as the bay area has more clay than iron and rock.
But even there it worked just fine.
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Robert Reed
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MrAl
And that was only 24 inches. Try moving out to 100 feet and you will see a much greater difference. My post had nothing to do Wikpedia or any other web site. These were actual testing situations done by me on a professinal level with dedicated professional equipment and by utility company standards which are universal throughout the country.
RSHayes
You are right on the money with every word you have printed. You could argue this all year with chris smith and he won't back down and by the time this post has ended, his wll be the last post and in his mind viewed as a victory in this argument.I have backed off from this post a bit, as myself ,you, and many others are merely arguing with a brick wall. And as to your knowledge and credentials that have been slandered here, I think almost the whole forum knows the superiority of your posts - so no contest there!
And that was only 24 inches. Try moving out to 100 feet and you will see a much greater difference. My post had nothing to do Wikpedia or any other web site. These were actual testing situations done by me on a professinal level with dedicated professional equipment and by utility company standards which are universal throughout the country.
RSHayes
You are right on the money with every word you have printed. You could argue this all year with chris smith and he won't back down and by the time this post has ended, his wll be the last post and in his mind viewed as a victory in this argument.I have backed off from this post a bit, as myself ,you, and many others are merely arguing with a brick wall. And as to your knowledge and credentials that have been slandered here, I think almost the whole forum knows the superiority of your posts - so no contest there!
Robert,
What is the significance of moving out to 100 feet?
We arent talking about two rods really here, are we?
Do you mean that the resistance at 100 feet is an indicator of
how good a single rod installation would be in a given area?
This is interesting because this says just how well we can expect
a rod to work in a given area. It's starting to sound like in some
areas it would work great (even if it's not legal) but in some
other areas it would not work at all. After all this conversation,
i would be afraid that even if it worked that later some time in
the future it would become unstable and would no longer work
effectively as a fix for anything (but then again i would also
have to wonder how some countries use the earth as a permanant return
line). This brings me to my next question for Chris...
Did you try that test in Death Valley yet?
So what are you saying now, that it works sometimes and sometimes
it doesnt?
Also, since every fix has a longevity factor somewhere along the line,
what do you estimate the mean time between failures to be, and
what do you base your (anticipated) figures on?
After all that has been said so far, do you feel that the original fix
you talked about is still an effective means of eliminating the harmonics
that can appear in the neutral, or do you feel that we have uncovered
some gray areas where the fix might not be applicable?
BTW, thanks in advance for the answers.
Also BTW, i still feel that it can be effective in some areas of the
world myself, as long as all the pitfalls and risks are known beforehand.
What is the significance of moving out to 100 feet?
We arent talking about two rods really here, are we?
Do you mean that the resistance at 100 feet is an indicator of
how good a single rod installation would be in a given area?
This is interesting because this says just how well we can expect
a rod to work in a given area. It's starting to sound like in some
areas it would work great (even if it's not legal) but in some
other areas it would not work at all. After all this conversation,
i would be afraid that even if it worked that later some time in
the future it would become unstable and would no longer work
effectively as a fix for anything (but then again i would also
have to wonder how some countries use the earth as a permanant return
line). This brings me to my next question for Chris...
Chris,Chris Smith wrote:
Also ground can vary hugely from dry sand to wet soils but if you want to see your ground and its effective value, do Like I did last night.
We have excellent soil values here with metals in the volcanic soil and rock.
Take a power cord, a light bulb, and socket with wires.
Place the return wire from the light to a grounded pole, the pole doesn’t even have to be very long.
Then light up the bulb. [and it is full bright]
Mined only showed a few volts that didnt make it to earth, and no neutral was even present.
That ground pole as long as it’s a foot or longer will work just fine.
Did you try that test in Death Valley yet?
So what are you saying now, that it works sometimes and sometimes
it doesnt?
Also, since every fix has a longevity factor somewhere along the line,
what do you estimate the mean time between failures to be, and
what do you base your (anticipated) figures on?
After all that has been said so far, do you feel that the original fix
you talked about is still an effective means of eliminating the harmonics
that can appear in the neutral, or do you feel that we have uncovered
some gray areas where the fix might not be applicable?
BTW, thanks in advance for the answers.
Also BTW, i still feel that it can be effective in some areas of the
world myself, as long as all the pitfalls and risks are known beforehand.
LEDs vs Bulbs, LEDs are winning.
-
Chris Smith
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-
Robert Reed
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- Location: ASHTABULA,OHIO
- Contact:
MrAl
I have not devoted my career to the study of earth ground characteristics, nor do I intend to in the future. My learning knowledge of this subject has been a moderate study of accepted printings by other qualified individuals and comittees,more out of curiosity than neccessity. My actual experience with these tests is as I have previously stated, and has been performed on several occassions in several widespead locations. I am not sure what you meant by two rods, but these tests were made from substation ground to a 36" stake ground at 100 foot distance. It was my assumption that this gave a better indication of the stations ability to dissipate lightning strikes effectively and for worker protection. Also, it was my understanding that earth resistance increased with increasing distance and that a current path between the two poles was not neccesarily a direct line between those two points due to changing content of soil, rocks and fissures and several other variables. The actual current path may be even quite longer than the 100 foot path "as the crow flies". These tests were made after initial construction and the at time intervals of several years that was compared back to the initial tests. These were done for the purpose of monitoring the integrity of the original installation. Any tests at time intervals other than this would have been for problem solving and suspicious peculiarities that might arise. A highly regarded trade journal in the utility industry is"Transmission and Distribution" magazine and has had frequent articles over the years in regards to this subject and agrees closely with results that I have experienced. Also I have never seen mention of single wire transmission lines, and this magazine does cover it's title subject all over the world so in that respect I offer no knowledge of that. As I said, I am no expert on the subject of earth grounding so I cannot answer every question you pose to me. But I can relate actual fact of what I have experienced.
I have not devoted my career to the study of earth ground characteristics, nor do I intend to in the future. My learning knowledge of this subject has been a moderate study of accepted printings by other qualified individuals and comittees,more out of curiosity than neccessity. My actual experience with these tests is as I have previously stated, and has been performed on several occassions in several widespead locations. I am not sure what you meant by two rods, but these tests were made from substation ground to a 36" stake ground at 100 foot distance. It was my assumption that this gave a better indication of the stations ability to dissipate lightning strikes effectively and for worker protection. Also, it was my understanding that earth resistance increased with increasing distance and that a current path between the two poles was not neccesarily a direct line between those two points due to changing content of soil, rocks and fissures and several other variables. The actual current path may be even quite longer than the 100 foot path "as the crow flies". These tests were made after initial construction and the at time intervals of several years that was compared back to the initial tests. These were done for the purpose of monitoring the integrity of the original installation. Any tests at time intervals other than this would have been for problem solving and suspicious peculiarities that might arise. A highly regarded trade journal in the utility industry is"Transmission and Distribution" magazine and has had frequent articles over the years in regards to this subject and agrees closely with results that I have experienced. Also I have never seen mention of single wire transmission lines, and this magazine does cover it's title subject all over the world so in that respect I offer no knowledge of that. As I said, I am no expert on the subject of earth grounding so I cannot answer every question you pose to me. But I can relate actual fact of what I have experienced.
Chris:
I have cited and quoted the applicable section of the NEC twice in this thread. I see no need to do it again. The words "shall not" appear in that section and they have a clear meaning in the English language.
I have never been, nor do I claim to be, an Electrician- either Apprentice, Journeyman, or Master.
You have been asked several times what your qualifications, if any, are. There has been no answer. In the absence of any qualification, your opinion has no particular weight.
Are you claiming to be an Electrical Engineer? This is a simple question. In English, the two possible answers are "yes" and "no".
I have cited and quoted the applicable section of the NEC twice in this thread. I see no need to do it again. The words "shall not" appear in that section and they have a clear meaning in the English language.
I have never been, nor do I claim to be, an Electrician- either Apprentice, Journeyman, or Master.
You have been asked several times what your qualifications, if any, are. There has been no answer. In the absence of any qualification, your opinion has no particular weight.
Are you claiming to be an Electrical Engineer? This is a simple question. In English, the two possible answers are "yes" and "no".
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Robert Reed
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MrAl
RSHayes
EDIT:
[Robert basically says that he does not agree with Chris on these issues]
I will make one final comment on the issue of load currents using mother earth as one of its current carrying paths, and then I am out of here as this thread is beginning to border on the ridiculous.
My analogy ---
A system must be devised to deliver power to a load that draws 10 amperes. After the normal design cycle is completed, the needed power supply is constucted and set into place.A 50 foot loop circuit is needed to supply power to that distant load, and 12 gauge wire is selected to provide minimal voltage drop. Manufacturer "X" provides the lowest cost for this wire and is chosen. However Manufacturer "X" also clearly states that their wire resistance for this loop length may have 1 or 2 ohms of resistance - or - it may have as high as 50 ohms resistance. They really don't know where it will fall in this range as they have very poor control of their manufacturing facilities and they offer no guarantees for dissatisfied customers. Would anyone in their right mind use this wire or would they be placing a call to a reputable wire manufacturer such as BELDEN about now. I think the answer is quite obvious.
RSHayes
EDIT:
[Robert basically says that he does not agree with Chris on these issues]
I will make one final comment on the issue of load currents using mother earth as one of its current carrying paths, and then I am out of here as this thread is beginning to border on the ridiculous.
My analogy ---
A system must be devised to deliver power to a load that draws 10 amperes. After the normal design cycle is completed, the needed power supply is constucted and set into place.A 50 foot loop circuit is needed to supply power to that distant load, and 12 gauge wire is selected to provide minimal voltage drop. Manufacturer "X" provides the lowest cost for this wire and is chosen. However Manufacturer "X" also clearly states that their wire resistance for this loop length may have 1 or 2 ohms of resistance - or - it may have as high as 50 ohms resistance. They really don't know where it will fall in this range as they have very poor control of their manufacturing facilities and they offer no guarantees for dissatisfied customers. Would anyone in their right mind use this wire or would they be placing a call to a reputable wire manufacturer such as BELDEN about now. I think the answer is quite obvious.
The 2005 NEC states in section 250.24(A)(5):
" Load -Side Grounding Connections.
A grounding connection shall not be made to any grounded conductor on the load side of the service disconnecting means except as otherwise permitted in this article."
This is the latest edition of the electrical code. The next revision is due in 2008.
The phrase "shall not" seem clear enough to me. It clearly "forbids". It also "prohibits". And there are several other ways of saying the same thing.
I also note that in the several hundred words Chris posted in his last post, he failed to indicate whether he was an Electrical Engineer. It is a very simple question that will require four or five keystrokes to answer. An answer would be especially appropriate in light of his numerous comments about amateurs, wannabees, etc.
So far, Chris is the biggest wannabee in this forum.
" Load -Side Grounding Connections.
A grounding connection shall not be made to any grounded conductor on the load side of the service disconnecting means except as otherwise permitted in this article."
This is the latest edition of the electrical code. The next revision is due in 2008.
The phrase "shall not" seem clear enough to me. It clearly "forbids". It also "prohibits". And there are several other ways of saying the same thing.
I also note that in the several hundred words Chris posted in his last post, he failed to indicate whether he was an Electrical Engineer. It is a very simple question that will require four or five keystrokes to answer. An answer would be especially appropriate in light of his numerous comments about amateurs, wannabees, etc.
So far, Chris is the biggest wannabee in this forum.
The page number is useless. There are at least three versions available from the NFPA, all with different page numbers (hardbound, paperback, and annotated). There are also other references that annotate the NEC from other publishers. The adequate and proper citation is the section number and this was given.
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Chris Smith
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- Location: Bieber Ca.
And I looked at exactly where you stated, [and in more than one web page and print] and there is nothing in that section that "forbids" any thing even resembling an extra neutral ground, and then after that, it led me to dozens of other examples, all stating that it is permissible including the figure 6 where the down stream tapped power to a unit [all after the panel] had a second "chassis to ground to neutral" post away from the original at the panel.
After that I learned all sorts of other features, and the closest negative they mention about extra neutral grounds is that don’t go hog wild, it only make it worse.
After that I learned all sorts of other features, and the closest negative they mention about extra neutral grounds is that don’t go hog wild, it only make it worse.
Chris,
You're wrong. DEAD wrong!
A GFI does not require a ground, and in fact it will work on an un-grounded circuit system. NEC 210-7 allows it use. A GFCI(GFI) works by comparing the current difference between the line and neutral. If an imbalance exceeds about 4-6ma it trips. The ground wire is not part of the circuit.
Applicable section, NEC210-7
3. Where a grounding means does not exist in the receptacle enclosure, the installation shall comply with (a), (b), or (c).
a. A nongrounding-type receptacle(s) shall be permitted to be replaced with another nongrounding-type receptacle(s).
b. A nongrounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked "No Equipment Ground." An equipment grounding conductor shall not be connected from the ground-fault circuit interrupter type receptacle to any outlet supplied from the ground-fault circuit interrupter receptacle.
c. A nongrounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked "GFCI
Protected" and "No Equipment Ground." An equipment grounding conductor shall not be connected between the grounding-type receptacles.
Unlike you, I don't make the rules, or theory, and won't carry this thread to oblivion!
You're wrong. DEAD wrong!
A GFI does not require a ground, and in fact it will work on an un-grounded circuit system. NEC 210-7 allows it use. A GFCI(GFI) works by comparing the current difference between the line and neutral. If an imbalance exceeds about 4-6ma it trips. The ground wire is not part of the circuit.
Applicable section, NEC210-7
3. Where a grounding means does not exist in the receptacle enclosure, the installation shall comply with (a), (b), or (c).
a. A nongrounding-type receptacle(s) shall be permitted to be replaced with another nongrounding-type receptacle(s).
b. A nongrounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked "No Equipment Ground." An equipment grounding conductor shall not be connected from the ground-fault circuit interrupter type receptacle to any outlet supplied from the ground-fault circuit interrupter receptacle.
c. A nongrounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked "GFCI
Protected" and "No Equipment Ground." An equipment grounding conductor shall not be connected between the grounding-type receptacles.
Unlike you, I don't make the rules, or theory, and won't carry this thread to oblivion!
Quick thought...
Using a high impedance meter on 'electrical' circuits can sometimes lead you down the wrong trail. Capacitive and inductive coupling can cause high or strange readings. A low Z meter loads the circuit and minimizes this error reading. Check any unused conductors in a current carrying conduit, you'll see lots of E but no I. Put the positive probe of a hi-z meter into the outlet line side, hold the negative lead in your hand, got a reading? You bet, but current is nil. Common sense first, confirm by test next.
Using a high impedance meter on 'electrical' circuits can sometimes lead you down the wrong trail. Capacitive and inductive coupling can cause high or strange readings. A low Z meter loads the circuit and minimizes this error reading. Check any unused conductors in a current carrying conduit, you'll see lots of E but no I. Put the positive probe of a hi-z meter into the outlet line side, hold the negative lead in your hand, got a reading? You bet, but current is nil. Common sense first, confirm by test next.
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