# Neutral Conductor



## Dennis Alwon (May 9, 2009)

Absolutely, sometimes with a neutral tat is going bad you can have all different voltage but the voltage between phases will always add to the source voltage. For instance if it is a 240V system you can have 180 on one phase and 60 on the other. You only see this when you have a load on.

Btw, welcome


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## Cletis (Aug 20, 2010)

*12*



BWStanton said:


> We have a problem with the neutral conductor being loose. The power company clams this will cause 220v on one leg and zero on the other. Has anyone run across this problem before? I have not.


Every 12 days. It's like clockwork


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## BBQ (Nov 16, 2010)

Here is a drawing from Ed MacLaren, an electrical instructor that used to post on the forums a lot. 

It illustrates what Dennis was talking about, the voltages will change depending on the loads.


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## Magnettica (Jan 23, 2007)

With the loss of a neutral in a 3-wire set up, the circuit changes from a parallel circuit, to a series circuit.


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## Southeast Power (Jan 18, 2009)

BWStanton said:


> We have a problem with the neutral conductor being loose. The power company clams this will cause 220v on one leg and zero on the other. Has anyone run across this problem before? I have not.


Please tell us you fixed it.

If you have an electric stove, you can turn on the big element and the lights will get brighter..:thumbsup:


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## frankwell (Mar 22, 2012)

This discussion is about why we need grounding electrodes.
A loose ground from the utility will cause voltage to fluctuate higher because of resistanse in the electrode system. Its a tough one to diagnose.
I saw a lose neutral in a Meter stack cause voltage on the 120 legs to go up and burned the TV's & 120V appliances.


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## BBQ (Nov 16, 2010)

frankwell said:


> This discussion is about why we need grounding electrodes.


The addition or presence of grounding electrodes does nothing to prevent over voltages if a neutral is open.


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## frankwell (Mar 22, 2012)

So you do not consider the earth as the extension or relocation of a center taped winding?


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## Dennis Alwon (May 9, 2009)

frankwell said:


> So you do not consider the earth as the extension or relocation of a center taped winding?


In general the earth will never have the ability to carry the current as a neutral does. For instance if you take a 20 amp circuit and touch the hot to the neutral you will undoubtedly create a dead short and hopefully trip the breaker. Now take that same circuit and touch the hot conductor to a sole ground rod driven in the dirt. I can almost guarantee it will not trip.


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## BBQ (Nov 16, 2010)

frankwell said:


> So you do not consider the earth as the extension or relocation of a center taped winding?


No, the connection between the earth and the electrodes have far to much impedance to hold the neutral at 0 potential relative to earth.


It would be the same as cutting open a neutral and installing a resistor into the circuit.


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## Cletis (Aug 20, 2010)

Dennis Alwon said:


> In general the earth will never have the ability to carry the current as a neutral does. For instance if you take a 20 amp circuit and touch the hot to the neutral you will undoubtedly create a dead short and hopefully trip the breaker. Now take that same circuit and touch the hot conductor to a sole ground rod driven in the dirt. I can almost guarantee it will not trip.


Can you do that and record on video?? Id like to see that.


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## electricalperson (Jan 11, 2008)

Cletis said:


> Can you do that and record on video?? Id like to see that.


its common sense. 120v too a 25 ohm ground rod

I = E/R = 4.8 amps

277v?

11.08 amps

i tested my ground rod and had 100 ohms


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## frankwell (Mar 22, 2012)

BBQ said:


> No, the connection between the earth and the electrodes have far to much impedance to hold the neutral at 0 potential relative to earth.
> 
> 
> It would be the same as cutting open a neutral and installing a resistor into the circuit.


And that is my point. You show it on you're posted sketch.
In the event a ground from the utility becomes open or reduced in capacity the electrode will take as much current, which in this case is unbalanced load, as said electrode impedance will allow.
At that point, impedance cannot be overcome. Then voltages on the 120V legs of a 120/250V 3W supply will fluctuate. At that point the customer senses a problem and calls for service.
Can you imagine how many broken overhead drops there are in the world.
There is no service call because of a good electrode usually in the form of a water main is carrying the neutral load.
Hence my deceleration that this thread is about grounding electrodes backing up the utility ground.


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## Cletis (Aug 20, 2010)

My grounding system is 0.5 ohms last i checked


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## dronai (Apr 11, 2011)

How can you accurately measure your ground rod resistance ?


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## Big John (May 23, 2010)

dronai said:


> How can you accurately measure your ground rod resistance ?


 You can do a fall of potential measurement. It tells you the resistance across the soil itself by applying a voltage across a pretty large distance and seeing what the drop is.

Unless Cletis lives in a copper mine, there ain't no way that's half an ohm. I'd expect the damn service neutral to be more than half an ohm.

-John


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## Cletis (Aug 20, 2010)

I have ufer grounds, clay, wet soil


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## Roger. (Dec 18, 2011)

frankwell said:


> There is no service call because of a good electrode usually in the form of a water main is carrying the neutral load.


That's because if a water system is metallic it is the metal piping completing the circuit, not the earth.

The earth will do very little if anything for the topic of this thread.


Roger


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## frankwell (Mar 22, 2012)

dronai said:


> How can you accurately measure your ground rod resistance ?


Measuring electrode resistance is a bit of work.
Most jurisdictions just ask for two ground rods as supplemental.
I am sure on transportation and communication projects the inspectors will start carrying around this equipment: 

http://www.megger.com/us/Products/ProductDetails.php?ID=1447&Description=det14c


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## dronai (Apr 11, 2011)

frankwell said:


> Measuring electrode resistance is a bit of work.
> Most jurisdictions just ask for two ground rods as supplemental.
> I am sure on transportation and communication projects the inspectors will start carrying around this equipment:
> 
> http://www.megger.com/us/Products/ProductDetails.php?ID=1447&Description=det14c


 
I know, but the way the others said they measured their Ground Rods sounded like they just used a DMM.


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## Big John (May 23, 2010)

dronai said:


> I know, but the way the others said they measured their Ground Rods sounded like they just used a DMM.


 There are ground resistance testers that just clamp around the rod.









I _think _they work by inducing a test signal and measuring how much bounces back and how much is lost. 

I've never seen any professional survey done with those things, and I've heard lots of questions raised about their accuracy. I think they're just a gadget for semi-trained inspectors.

-John


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## Dennis Alwon (May 9, 2009)

Cletis said:


> My grounding system is 0.5 ohms last i checked


When you say things like this you confuse members. They don't realize you are playing around.


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## kbsparky (Sep 20, 2007)

jrannis said:


> Please tell us you fixed it.
> 
> If you have an electric stove, you can turn on the big element and the lights will get brighter..:thumbsup:


Incorrect. 240 Volt loads are not affected by a loose/missing neutral, nor will they affect 120 volt loads that are dependent on a neutral connection.

Your statement would be correct if one of the hot legs was loose or missing, however.


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## dronai (Apr 11, 2011)

kbsparky said:


> Incorrect. 240 Volt loads are not affected by a loose/missing neutral, nor will they affect 120 volt loads that are dependent on a neutral connection.
> 
> Your statement would be correct if one of the hot legs was loose or missing, however.


 
See my thread http://www.electriciantalk.com/f2/theory-open-neutral-36386/


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## Theriot (Aug 27, 2011)

I'm confused what does Clitis mean ohms?? Lol


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## BBQ (Nov 16, 2010)

Big John said:


> Unless Cletis lives in a copper mine, there ain't no way that's half an ohm.


I don't know why but that really made me laugh. :laughing:


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## brian john (Mar 11, 2007)

Big John said:


> You can do a fall of potential measurement. It tells you the resistance across the soil itself by applying a voltage across a pretty large distance and seeing what the drop is.
> 
> Unless Cletis lives in a copper mine, there ain't no way that's half an ohm. I'd expect the damn service neutral to be more than half an ohm.
> 
> -John


I have tested many electrodes systems less than .5 ohms and I have tested many that had numbers in the stratosphere.

I was once paid to sit and keep testing the electrode until they reached 5 ohms, and the system got bigger and bigger, took them 2 days to reach 5 ohms, a lot of 8’ electrode and copper.


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## brian john (Mar 11, 2007)

Big John said:


> There are ground resistance testers that just clamp around the rod.
> 
> 
> 
> ...


Not an approved acceptable method of testing. To many people utilized them in a manner they were not designed for and the numbers are meaningless.


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## brian john (Mar 11, 2007)

frankwell said:


> Measuring electrode resistance is a bit of work.
> Most jurisdictions just ask for two ground rods as supplemental.
> I am sure on transportation and communication projects the inspectors will start carrying around this equipment:
> 
> http://www.megger.com/us/Products/ProductDetails.php?ID=1447&Description=det14c


 
Most would know what they were doing, would not perform the test properly and as noted the numbers would be meaningless.


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## Big John (May 23, 2010)

brian john said:


> I have tested many electrodes systems less than .5 ohms and I have tested many that had numbers in the stratosphere...


 I don't doubt that there are systems that really are in the fraction of an ohm. However, I doubt very much that one or two electrodes Cletis has measure 0.5 ohms, regardless of the soil conditions... but I think I'm letting myself get trolled.

You taking a page from_ The Book of Chicken Steve_ with that new font? :laughing:

-John


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## brian john (Mar 11, 2007)

Big John said:


> You taking a page from_ The Book of Chicken Steve_ with that new font? :laughing:
> 
> -John


New PC and I can't get spell check up, so I cut and paste from Word, this is what IO get and it changes regularly.

And as any of you know MY SPELLING STINKS.


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## electures (Oct 23, 2008)

frankwell said:


> Measuring electrode resistance is a bit of work.
> Most jurisdictions just ask for two ground rods as supplemental.
> I am sure on transportation and communication projects *the inspectors will start carrying around this equipment: *
> 
> http://www.megger.com/us/Products/ProductDetails.php?ID=1447&Description=det14c


 
No, I just need to witness the test the EC conducts with *his* equipment.


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## BBQ (Nov 16, 2010)

Big John said:


>





brian john said:


> Not an approved acceptable method of testing.


Not approved by who?

Your customers? 

Certainly many engineers specify 3 point FOP testing but there is no general rule saying this awful method is not approved.


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## Southeast Power (Jan 18, 2009)

kbsparky said:


> Incorrect. 240 Volt loads are not affected by a loose/missing neutral, nor will they affect 120 volt loads that are dependent on a neutral connection.
> 
> Your statement would be correct if one of the hot legs was loose or missing, however.


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## brian john (Mar 11, 2007)

Bob,

From a NETA article on Clampon testing, 
• Too easy
• Unverifiable
• *Lacking standards approval*
• Requires multiple returns
•* Less accurate*
• *Cannot test soil resistivity*


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## Cletis (Aug 20, 2010)

*Sperry*

I heard Sperry is coming out with another high quality product that just clamps on ground rod and tells you if it's good or bad for Home Inspectors. $14.99


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## BBQ (Nov 16, 2010)

brian john said:


> Bob,
> 
> From a NETA article on Clampon testing,
> • Too easy
> ...


The AHJ can accept it.

That said having played with one side by side with a FOP test kit I think the clamp on one is a joke.


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## hoangd (Apr 15, 2012)

a loose or missing neutral will cause unbalanced voltages with loads on.


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## CelticElect (Nov 17, 2011)

dronai said:


> How can you accurately measure your ground rod resistance ?


With a megger.


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