Strange AC Power Issue

[dyarker]

[Chris Smith]

Poor phil, he lost a chunk of the rear section, now he is trying desperately to find it.

Ohh well, you got a chance to learn things you didn’t have a clue about because you never even thought about such things.

You learned about what a neutral really is....Neutral is a circuit conductor that may carry current in normal operation, and which is usually connected to Earth.
http://en.wikipedia.org/wiki/Ground_and_neutral

I wonder how many spice programs you ran before you found that missing rear chunk that went missing on day one.

I wonder if you ever had have the huevos to even try.

The laugh is on you.

You can try and change history all you like with your opinions and rhetoric.

Im not interested, my history is sound and working just fine.

I wonder IF you will ever even get one with the size of your blinders?

[dyarker]

The only one not learning anything is you! Quote from the Wikipedia page you just linked -

"In the USA, the chassis/cases of some ovens and clothes dryers were grounded through their neutral wires, as a measure to conserve copper during the Second World War. This practice was removed from the NEC in the 1996 edition, but existing installations may still allow the chassis/case grounding of such appliances to be connected to the neutral conductor. Note that the NEC may be amended by local regulations in each state and city. This change to the NEC was implemented because ovens and dryers have components that use both 120 and 240 volts, and thus there is often current on the neutral wire. This differs from the protective grounding wire, which only carries current under fault conditions. A chassis connected to the grounding wire is generally safe because the heavier wire that feeds high-power appliances is less likely to break. The bonding connection between the neutral and grounding wires is only to be done at the main service panel." Bold added so maybe you can see it.

Again the babbler didn't read his own reference. Or, maybe your house is a Tram (see elsewhere in the page)?

[Robert Reed]

Dyarker

Chris appears to go from a desperate search in Wikpedia for information and then directly to this Forum with his post. Since he never really understands what he just read explains his unreadable posts.

[MrAl]

Starting to sound like good 'grounds' for divorce...ha ha, couldnt
resist that one

On the more serious side, i believe Chris' idea would really work,
but it's highly questionable if it is still legal in this day and age.
This leads me to believe that other methods should be sought
after first, and if nothing else works (without expense that is)
then the code for that particular area would have to be consulted
before actually implementing the Chris fix. There could be another
reason why they dont seem to want that anymore that we dont
know about yet, so it gets hard to say you can do it without danger.
I know if i was contracted to do that job, i would want to do it the
cheapest way i could find, but of course without violating any
codes in that area.

One thing i dont see yet though, and that is although i believe Chris'
idea would work, i dont see it as being particularly easier than say
adding another neutral wire, provided of course there are no transformers
to deal with closer to the source.

The Chris fix would be cheaper though, just not sure if you would be
able to get away with it in every area, nor if it is, strictly speaking,
"totally safe" to do.
One thing we could look at is possible failure modes...that is, if the
Chris fix is implemented, what could go wrong in the near or distant
future? I cant answer this because i dont know all the possible
scenarios that could come up, but perhaps something somewhere
went wrong when this idea was used at some point and that's why
it doesnt seem to be used anymore. I dont know for sure though.
One possibility would be that with 'extra' neutrals, an electrician
would not be able to measure the current that exists in the neutral
wires by simply going to the box and measuring each one...he would
instead have the daunting task of having to go to every single box in the
building and measuring each and every neutral wire independently.
Also the neutral wire could no longer be 'shut off' at the box, if that
matters at all.

I guess another thing to think about is that some areas of the world
are lucky to even have electrical power. If they had this problem they
would probably just drive a stake into the ground and call it 'another
neutral' too. In the more civilized world though, we have codes that
have to be followed.

Last but not least, i would add that it's not going to help to mock
each other out no matter how 'wrong' or 'dumb' the other person seems
to be. It's just going to make matters worse for random surfers of
this site. Also, if you feel that strongly about arguing with someone
in particular you can always PM them right? You can then hash it
out there and leave the thread more readable to others.
Or, if nothing else works, get a divorce

[Chris Smith]

My fix on my work shop was one fix for my job, others had the same fix and it worked for them as well because in simple English it works.

How you accomplish better grounding or full circuit returns varies from job to job.

What you do about harmonics depends on the equipment and the circumstances.

Any way you look at it or even agree, the facts still remain and what you do about them is up to your understanding, or lack there of.

The spice / cad shows it works, and in other cases the same thing works in different ways when that’s possible.

All mentioned.

Slab floors also present earth grounding.

All the pseudo experts here said it cant or wont work.
[no experience, just lip]

Some still do!

But none here as usual even considered the real concept behind the wiring. They are too worried about scoring points for the clique.

Some said don’t be blinded, harmonics doesn’t exist.

Others said it has nothing to do with nothing.

Yet even bigger fools said “he is only trying to make a smoke screenâ€

[positronicle]

--Edited by Positronicle--

[Chris Smith]

You have said nothing, you have achieved even less.

How many wasted posts is that now?

The price of tea in china is still irrelevant.

And by the way, do try and read my words, leave your own out and stop quoting stupid answers like that had anything to do with the print I have given.

Your example isnt even close to what I have said, your soo far out you will note there is no retort because it had nothing to do with me or my post.

The price of tea is still irrelevant and it has nothing what so ever to do with my print.

Your better off talking about the the flowers if you dont have a clue about my words.

Monty Python all over.

[Robert Reed]

MrAl
This post has taken off in many different directions that I have to stop and think what point we are aguing about. Oh ,yes it was the origiinal comment of using mother earth as a loads conduction path! And being that, I have to take issue with part of your last post and please forgive me if I misread it. It appears that you partially agree with chris smith about using earth ground as an added load current path back to the service entry. At this point I will inject an excerpt from my former post --

Chris seems to be under the illusion that utility companys some how use earth as part of their distribution system.Nothing could be further from the truth. In terms of efficient power delivery, the earth is a terrible conductor. I worked for a major electric utility company for over 10 years and I learned just about every facet of their operations. I have conducted substation ground tests on several occasions. These were measured at 100 ft distances from the station and using professional BIDDLE earth ground resistance test aparatus. The results were generally 10 to 60 ohms and would vary somewhat by season. Our area has a fairly high water table, but out west I have heard they run well over 200 ohms on these tests. Substaions have a ground system that would put commercial AM antenna systems to shame, so these readings are far more favorable than any residential or commercial system (unless they were built in the middle of the Okenfenocee swamp).Now just imagine sending 20 amperes for 1/2 mile thru this stuff.

Aside from being a clear safety violation as has been pointed out numerous times here by knowledgeable people, it would be quite an assumption that the earth would carry much current at all from the load back to the service entry and in most cases would not make an appreciiable difference in the overall cuurent carrying capacity of any particular branch. Also, and for the moment putting safety aside for now, from an engineerig standpoint, no one would even consider using earth as a substitute for copper wire as to the tremendous amount of variables it would present. Like I said, I may have misinterpreted your comment as I can't beleive that a knowledgable man as yourself would agree with setting up any sort of power loop in that configuration.

[Chris Smith]

Robert

Then you will have no problem explaining why mine worked, instead of just more of your negative rhetoric.

Explain how a neutral that is only carrying back 103 volts and dumping 17 potential volts back at the job, suddenly now receives 119.5 + volts. [the neutrals only show less than one volt in operation]

The neutral now show almost no power at its lead or the bare equipment that may be present, and that all the oscilloscopes that once had harmonics, suddenly stopped.

[yes even the o scope can show you that]

All of the delivered voltage is now in use.

Were not talking about efficiency, were talking about getting the left over voltage away from your hand safely, or the harmonic to quieten down.

Your soo good with the spice models, tell us, were waiting.

Where does the excess back up go, if not to dedicated ground?

So what if ground is a bad wire, its huge and it takes the power out of your hand or equipment.

Now I am assuming you have zero answers here, but Im also sure you don’t like to admit your wrong, so simply go away rather than admit your mistakes, its that simple.

As long as you learned something, we have a winner.

[Robert Reed]

Since when did your name become MrAl? If I wanted more of your cockeyed opinions I would have adressed you.

[Chris Smith]

Would you like me to look for that missing rear piece?

Give me a break, child psychology of a five year old is more subtle.

[MrAl]

Hi again,


Robert:
If i understand you correctly, you are saying that a ground connection
can have 10 to 60 ohms resistance, and that's on a good day. 200 ohms
could occur where the land is drier (less conductivity). You also
say that these readings would be better than most installations because
connections in substations are made better than other types like
residential or commercial.

If what you are claiming is true, then that means that no ground, anywhere,
actually works as a ground! 60 ohms between the ground on a typical house
outlet box and earth would lead to what i would call a 'bad ground'.
In other words, with a 1000 watt appliance connected to an outlet
and with a failed neutral and a short from box neutral to ground would
produce 96.8 volts ac on the ground lead at the box. Moreover, since
the load current would only be 1.6 amps the 20A breaker (or fuse) would not
trip. Having almost 100 volts at the ground is almost like no protection
at all, but that's not even worst case. Worst case is having a short from
hot to ground, which would put the whole 120v ac on the ground lead and
the breaker still wouldnt trip because the current would only be 2 amps
and no way will that trip a 20 amp breaker or fuse.
Now on the low end of your ohms parameter range, 10 ohms would only cause
12 amps to flow and that would still put 120vac on the ground terminal
of the house box and the breaker still wouldnt trip.

Naturally you can see how this sounds way too hard to believe because
what you are basically saying is that every ground everywhere in the world
does not work.

How long ago were those measurements made and could anything have
improved since then, or did i misunderstand you?


Here's some quotes from various sources:
-------------------------------------------------------------------------
Whatis.com:
The earth, which forms the ultimate ground, has the ability to
absorb or dissipate an unlimited amount of electrical charge.

Wikipedia.org:
Earths are commonly used in electricity supply companies' wiring
and occasionally for fixed wiring in buildings and for some
specialist applications where there is little choice like railways
and trams. Since normal circuit currents in the neutral conductor
can lead to objectionable or dangerous differences between local
earth potential and the neutral and to protect against neutral
breakages, special precautions such as frequent rodding down to
earth, use of cables where the combined neutral and earth completely
surrounds the phase conductor(s), and thicker than normal equipotential
bonding must be considered to ensure the system is safe.
-------------------------------------------------------------------------

Are they all BS?


This isnt to say that i believe that a ground fix or install could *become*
a bad ground, with very high resistance. I've seen a ground pole stuck in
a hole where the hole was 2 inches in diameter at the top and the pole
only maybe 3/4 inch diameter, and if you shake the top of the pole back
and forth gently with your hand the whole pole moves back and forth
which indicates that it is not in good contact with the earth. This was
on an actual house installation too. I dont know how they do it these
days, but i would hope it is better than that. One day when a big
truck went by and pulled the main overhead line down, a licenced electrician
had to be called and when the line was repaired a new ground was also
installed which consisted of a new pole driven into the ground (i dont
know how deep it was driven) and a new connection to the main breaker box
ground.

[Robert Reed]

Hello again MrAl

"If what you are claiming is true, then that means that no ground, anywhere,
actually works as a ground! 60 ohms between the ground on a typical house
outlet box and earth would lead to what i would call a 'bad ground'.
In other words, with a 1000 watt appliance connected to an outlet
and with a failed neutral and a short from box neutral to ground would
produce 96.8 volts ac on the ground lead at the box. Moreover, since
the load current would only be 1.6 amps the 20A breaker (or fuse) would not
trip. Having almost 100 volts at the ground is almost like no protection
at all, but that's not even worst case. Worst case is having a short from
hot to ground, which would put the whole 120v ac on the ground lead and
the breaker still wouldnt trip because the current would only be 2 amps
and no way will that trip a 20 amp breaker or fuse.
Now on the low end of your ohms parameter range, 10 ohms would only causeI"I
12 amps to flow and that would still put 120vac on the ground terminal
of the house box and the breaker still wouldnt trip."

This is exactly the reason for the safety gound wire. The defective apparatus's short to its grounded case would immediately be picked up by the safety ground wire and trip the breaker immediately due to the safety ground being a solid and reliable conductor. Don't get me wrong on mutiple grounds in a system as I have mentioned on several occasions that it could only improve the system and not hurt it. But these earth grounds are tied only to the safety ground wire and not the neutral thereby insuring that load current only flows through the neutral wire back to service entry. As a matter of interest on this point Transmission & Distribution magazine ran an article about 3 months ago thoroughly covering this subject and with regards to substation construction workers safety. Their ground resistance tests were very similar to the results that I had experienced.
As to earth grounds, In our area code requires a 1/2" X 8 foot copper clad ground rod driven in as close as pratical to the service entry box and an extension bracket is available for attaching another 8 foot section if our local utility company deems it neccessary. I would imagine our local code follows NEC fairly closely on this as most other rules seem to fall in line.

[haklesup]

Here's a Simple test.

Wire a 100W light bulb between hot and ground (instead of neutral, you can ignore that wire for now). Plug it in.

If the lamp lights to full brightness, you have cood continuity back to neutral at the panel. The voltage at ground (WRT neutral) will remain 0V.

If it lights dim, your ground is connected to earth only and the brightness is proportional to the resistance. The volatage at ground WRT neutral can be anything from a few volts to full AC.

If it does not light at all, the ground is open or your earth ground is poor. The voltage at ground will be the same as the hot wire while the bulb is plugged in.

This can be a hazardous test so unplug anything with a ground prong and do it with no one else home. Plug it in only as long as you need to.

This is essentially the same thing a socket tester does but that tool uses almost no current due to the neon bulbs and this test does it under a decent load.

For ground I use a peice of rebar sticking out of the foundation. Seems to work well but as you would imagine, it is difficult to measure the true impedance of your particular ground spike unless you intentianally open the neutral - ground jumper in the panel and do a test like I described above.

If you use ground only as a voltage reference, a high impedance connection is sufficient and if you only looked at voltage measurements, you wouldn't know the impedance. For the purpose of dumping large amounts of stray current to protect people, you would need a low impedance ground.

Spiking a floating ground will nearly zero out the voltage but unless there is a short curcuit fault you won't know if it is sufficient without such a load test. Also since ground impedance is influenced by ground moisture, the results may vary throughout the year.