# Ground Rod Resistance



## Speedy Petey (Jan 10, 2007)

_*250.56 Resistance of Rod, Pipe, and Plate Electrodes*
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 of any of the types specified by 250.52(A)(2) through (A)(7). Where multiple rod, pipe, or plate electrodes are installed to meet the requirements of this section, they shall not be less than 1.8 m (6 ft) apart._


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## brian john (Mar 11, 2007)

One rod 25 ohms drive two rods and anything you get or don't get, because there is no requirement to measure the resistance.


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## wirenut1110 (Feb 12, 2008)

As Brian said, just drive 2 then there's no question, except what $10?


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## Billy716 (Jun 26, 2008)

What we've got is a very sandy desert area and are having a hard time getting a good ground.


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## wirenut1110 (Feb 12, 2008)

how are you determining "not a good ground"?


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## Billy716 (Jun 26, 2008)

There's no difference of potential from the hot to the rod. We are already down two sections of rod.


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## brian john (Mar 11, 2007)

That is not how you measure ground resistance and most likely means little to nothing.

Second who is requiring this?

What if anything is the spec?


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## Billy716 (Jun 26, 2008)

I'm stuck in Iraq. I don't have the right equipment. I don't have a good ground and I am trying to get one. The sand here is unbelievable and goes down forever.


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## brian john (Mar 11, 2007)

WHY WHY WHY.......WHY..


What is the requirement requiring this GOOD GROUND WHY.

I am not being sarcastic I am SERIOUSLY trying to understand why. What is driving this?


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## Billy716 (Jun 26, 2008)

I'm frustrated. We've had at least 12 soldiers die of electrocution due to poor grounding. The pressure is on us to make sure we have it and rightfully so. We are having a hard time getting it and I am looking for some suggestions.


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## brian john (Mar 11, 2007)

In our industry there is this driving need to have a low resistance to earth. In the realm of all electrical requirements for safety this ranks at the bottom of the list.

Are there times where a low earth resistance is necessary YES, but seldom is this the case in a typical electrical installation, Good bonding YES, Low resistance grounding utilizing ECG's between equipment yes. But driving a rod into the earth. WHY?


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## Speedy Petey (Jan 10, 2007)

Driving a ground rod will NOT(!) cure an electrocution problem!

I can't believe there are no engineers (or whatever) there that know this.


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## brian john (Mar 11, 2007)

NO you did not, you has 12 electricians die from poor electrical wiring and poor BONDING of all metallic parts. Earth has nothing to do with this and until you (those involved in this not necessarily you) understand this some will continue to be hurt.

Hell if the earth is that lousy of a conductor, it is actually safer you can hold a ungrounded/hot/energized conductor and stand bare naked on the earth SAFELY.

SCREW THE GD EARTH... install proper wiring with proper grounding (BONDING) of all metallic parts.


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## JohnJ0906 (Jan 22, 2007)

Billy716 said:


> I'm frustrated. We've had at least 12 soldiers die of electrocution due to poor grounding. The pressure is on us to make sure we have it and rightfully so. We are having a hard time getting it and I am looking for some suggestions.


They did not die from poor grounding. They died from poor bonding.

What will a stick in the earth do to prevent these deaths?


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## Stickboy1375 (Jul 23, 2007)

Billy716 said:


> I'm stuck in Iraq. I don't have the right equipment. I don't have a good ground and I am trying to get one. The sand here is unbelievable and goes down forever.


What makes a good ground? if you dont have the right equipment, how do you know you have a bad ground? FWIW, it has nothing to do with clearing a fault and tripping the OCD...


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## cmec (Feb 11, 2008)

I have dug around rods & put a piece of terra cotta tile or pvc up on end fill it with rock salt and water it then take a reading drops the resistance real quick in normal soil,If you dont have any enviromentalist /tree huggers copper sulfate works good. dont know what chemical to use for sand?

They sell rods that are hollow you can put chemicals in .


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## Stickboy1375 (Jul 23, 2007)

cmec said:


> I have dug around rods & put a piece of terra cotta tile or pvc up on end fill it with rock salt and water it then take a reading drops the resistance real quick in normal soil,If you dont have any enviromentalist /tree huggers copper sulfate works good. dont know what chemical to use for sand?



Is lightning a huge threat in the desert?


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## brian john (Mar 11, 2007)

CMEC:

There are a variety of methods for lowering ground resistance, do a web search, DEEP EARTH GROUNDING, XIT, hell if I thought it would help I'd GIVE a 3-point tester, pay the shipping and give an online tutorial to billy716, BUT this is not the problem, not the issue, not the solution.

I want him and all our soldiers and contractors to be safe. There are ways to make this happen but peeing on a stick in the earth ain't he solution.


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## te12co2w (Jun 3, 2007)

I've read about this. Soldiers dying in the showers. I wondered at the time what was wrong, but it sounds as if it is more than just inadequate ground. I am guessing you use generator power over there. Whatever is causing this might be coming from energized piping and a good earth ground in the same area. Electric water heaters? Maybe you don't need water heaters in Iraq. If you have an overhead distribution system with a common grounding point that is tied to neut, then maybe that bond has failed. For all I know, you don't even use 2 hots and a neutral like we do in the states. 
Measure across various pipes to drains or metal dividers until you find where the voltage is. Then shut down all power to your site and measure again. If the voltage is gone then turn on circuits one by one until it appears again. Then troubleshoot that circuit. If the voltage does not go away, then suspect your nearest neighbors. Check for solid neutral connections at neighbor's panels. You can even get voltage from phone wires that are damaged and lying on anything conductive. eg. metal pipes. roofing, metal walls. I don't know if phone voltage is enough to kill a person though.
This situation is tragic. You guys over there have enough to worry about without having to think about checking out in a shower where you should be safe. 
Good luck and may God bless all of you.


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## JohnJ0906 (Jan 22, 2007)

The planet earth is NOT a fault path. Not enough current will flow to operate a fuse or circuit breaker at lower voltages.
250.4(A)(5) and 250.4(B)(4) Actually, read 250.4 in its entirety.


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## cmec (Feb 11, 2008)

BRIAN

I am missing somepthing here ,He asked about grounding,are you saying they use neutrals for grounding not a seprate equipment grounding conductor?


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## JohnJ0906 (Jan 22, 2007)

About a year or so ago, an electrician from Iraq posted on a different electrical forum about his concerns regarding the installation practices in use over there.

As memory serves, they did not use any EGCs. There was no fault path to source.


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## brian john (Mar 11, 2007)

> BRIAN
> 
> I am missing something here ,He asked about groundings are you saying they use neutrals for grounding not a separate equipment grounding conductor?


 
NO! You said you had done various practices to lower resistance to earth. I am saying the ohmic resistance to earth has nothing to do with saving lives in this case. There are cases where a low ohmic resistance to earth is necessary, but in this case this is not the issue.

BUT

A neutral is a GROUNDED CONDUCTOR. In addition there should be a equipment grounding conductor and an ungrounded conductor(s). 

A feeder, branch circuit should include a grounded conductor an ungrounded conductor and a equipment grounding conductor.

Even in an ungrounded system, NO INTENTIONAL connection from any current carrying conductor to *ground. There is a EGC and bonding is mandatory.


*GROUND while the NEC does require a connection to earth, this connection is for lightning and unintentional connection to the utility as in the case of a transformer failure. WHAT IS CRITICAL is bonding all metallic parts, building steel, water pipes, ducts, tent poles, metallic tables, metal shower enclosures. BONDING


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## wirenut1110 (Feb 12, 2008)

As a few have said, bond your pumps, piping etc. As Petey says, that has to be EE's there for Christ's sake. Does anyone know WTF they're doing??????? We've read about these electrocutions while taking shower. UNF"NBELIEVABLE however, what we read is "it's not our job"


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## Billy716 (Jun 26, 2008)

te12co2w said:


> I've read about this. Soldiers dying in the showers. I wondered at the time what was wrong, but it sounds as if it is more than just inadequate ground. I am guessing you use generator power over there. Whatever is causing this might be coming from energized piping and a good earth ground in the same area. Electric water heaters? Maybe you don't need water heaters in Iraq. If you have an overhead distribution system with a common grounding point that is tied to neut, then maybe that bond has failed. For all I know, you don't even use 2 hots and a neutral like we do in the states.
> Measure across various pipes to drains or metal dividers until you find where the voltage is. Then shut down all power to your site and measure again. If the voltage is gone then turn on circuits one by one until it appears again. Then troubleshoot that circuit. If the voltage does not go away, then suspect your nearest neighbors. Check for solid neutral connections at neighbor's panels. You can even get voltage from phone wires that are damaged and lying on anything conductive. eg. metal pipes. roofing, metal walls. I don't know if phone voltage is enough to kill a person though.
> This situation is tragic. You guys over there have enough to worry about without having to think about checking out in a shower where you should be safe.
> Good luck and may God bless all of you.


Thank You!! One of our biggest problems is utilizing Iraqi built and wired buildings. Then hooking them up to a generator. The voltage is 230 volts instead of 110. 

The plumbing and electrical is a hodge podge. But we are at least trying to get as good a ground at the generator so we can run out stuff back to that. The plumbing "appears" to be well grounded...old steel pipe. We are looking at that as well. And no we don't have any engineers here.


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## brian john (Mar 11, 2007)

Not trying to make light of this BUT..




> I am guessing you use generator power over there


I think 99.9 percent of our power comes from generators.


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## cmec (Feb 11, 2008)

I would like to see some pictures and digrams of how everything is set up?.


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## Billy716 (Jun 26, 2008)

Ours are mobile and come in a damn conex box. Thanks for the help. It's 4:15am and I need to go to work.


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## Billy716 (Jun 26, 2008)

cmec said:


> I would like to see some pictures and digrams of how everything is set up?.


Sorry. No can do...it's military installation. No pics.


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## cmec (Feb 11, 2008)

Billy716 said:


> Thank You!! One of our biggest problems is utilizing Iraqi built and wired buildings. Then hooking them up to a generator. The voltage is 230 volts instead of 110.
> 
> The plumbing and electrical is a hodge podge. But we are at least trying to get as good a ground at the generator so we can run out stuff back to that. The plumbing "appears" to be well grounded...old steel pipe. We are looking at that as well. And no we don't have any engineers here.


Whats the generator tapped for 120/240 1 phase with a grounded neutral to the rod? at the generator, and 230 in the building with no neutral?.


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## Billy716 (Jun 26, 2008)

cmec said:


> Whats the generator tapped for 120/240 1 phase with a grounded neutral to the rod? at the generator, and 230 in the building with no neutral?.


It is 250/380. Not anything like it is in the states. It ranges from 230-250 1 phase to ground/neutral.


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## brian john (Mar 11, 2007)

With basic safety issue and installation, the voltage does not matter (yes there are some issues with utilizing higher voltages). If the system is a 240/120 single phase, 208/120 three phase it matter not. There are basic grounding practices outlined in Soares Book on Grounding, NEC Handbook, and a variety of others. This is electricity 101 and that anyone is getting hurt/dying from PISS POOR installations is sickening.

1. Assuming 3 phase wye (most military generators I have worked on were re-connectable 208/120 and 480/277 wye (though other configurations are available).
2. XO/4-5-6-10-11-12 on a 208/120 system, at 480/277 this XO is10-11-12 (from the generator) and these are grounded that is – 
a. Drive an electrode and BOND (connect) this to the frame of the generator, to the connex box (which is in contact with the earth). This resistance is insignificant to the overall safety of the users of the system.
b. This connection is Equipment Grounding Conductor (EGC) utilized with every feeder and branch circuit you utilize, from this point on the connection to earth MEANS NOTHING.
c. At no point are you to use this EGC for any connections to load this conductor only carries current in the case of a fault (and small leakage current that is negilable).
d. With the system up and running measure current at the generator. There should be current on all ungrounded conductors (hot energized) and a portion of this current should be on the grounded conductor/neutral (see below). There should be no current on the EGC.
e. The EGC should be comprised of ALL metallic structures all surfaces capable of carrying current, all these surfaces should be connected back to the XO/4-5-6-10-11-12 on the generator.

That Iraqis are doing any wiring is not an issue. SOME ONE HAS TO BE IN CHARGE AND HAS TO BE RESOPNSIBLE TO INSURE THIS WORK IS COMPLETED PROPERLY. And if not you the responsible person you need to do all in you power to explain the situation to the responsible person and/or resign.

http://www.constructionbook.com/default2.asp?keyword=grounding
IM me and I will give you my email address I will send any literature you want I have tons of literature on this subject. Hell get me a ticket and I'll show/teach all the responsible parties how to SAFELY complete a temporay installation. THIS HAS GOT TO STOP.


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## HighWirey (Sep 17, 2007)

brian john said:


> Not trying to make light of this BUT..
> 
> I think 99.9 percent of our power comes from generators.


Brian,

Your statement is incredulous. I've never heard of an electrician never trying to make light 

Work'in For That Free Tee . . .


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## te12co2w (Jun 3, 2007)

I hope you find the solution before anyone else gets hurt or killed. Please keep us informed.


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## te12co2w (Jun 3, 2007)

Billy716 said:


> It is 250/380. Not anything like it is in the states. It ranges from 230-250 1 phase to ground/neutral.


 Is this system used because your generators provide that or is that a normal Iraqi setup? Do you use regular breakers like we do?


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## brian john (Mar 11, 2007)

This is most likely 3 phase 4 wire wye, voltage makes no difference in the whole realm of things.

May even be 50 HZ. 

When I lived in Europe and Turkey this was the standard. 

There are safeety measures taken that could REALLY make a difference RESIDUAL/ZERO SEQUENCE Ground Fault Protection, with settings in the low end. I know in England they use GFP on the main in resisdences with low settings 50 milliamps(?) Frank from the UK has discussed this.

http://www.carlingtech.com/news/pdf/pr75_43691_GFCICAT_3_20_2008.pdf 

What I would assume Billy has for distribution:

A to neutral and or ground 230 VAC
B to neutral and or ground 230 VAC
C to neutral and or ground 230 VAC

A-B Phase to Phase 230X1.732=398 (400 nominal)
B-C Phase to Phase 230X1.732=398 (400 nominal)
C-A Phase to Phase 230X1.732=398 (400 nominal)


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## brian john (Mar 11, 2007)

> Your statement is incredulous. I've never heard of an electrician never trying to make light


heck some of us (NOT ME) think the sun shines from our butts we are so hot.


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## Burt (Jun 29, 2009)

*Different countries, different systems, different codes, if any*


In the past twenty years of doing grounding work around the world we have learned that many countries have systems with no grounds and/or no grounds/neutrals, or no neutrals supplied by the utilities.
Many are updating their requirements to protect new electronic equipment as well as people.
Therefore, depending on the utility to supply protection or expecting the NEC, or any other code, to be implemented may be a false assumption.
Even if they have codes, they may not be enforced. Bonding is absolutely essential but all it takes is one technician to change something after the installation and not bond it correctly to cause serious problems.
We have found a single point ground bus internally bonded to a low resistance exterior grid works best, 100% of the time.
We never use chemicals, just copperclad electrodes.
Of course, its only, as it is here in the US, a question of money and how serious they want the protection.


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## zen (Jun 15, 2009)

last year i had a friend of mine come back from afganistan,he went there to do electrical work, he said 3 men died in the showers there also, he went on to say hes embaressed to say hes done alot of the work over there because they dont have tools and equipment. it seems the motto is make it work by whatever means necessary safe or unsafe.code has no place in war


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## captkirk (Nov 21, 2007)

brian john said:


> NO you did not, you has 12 electricians die from poor electrical wiring and poor BONDING of all metallic parts. Earth has nothing to do with this and until you (those involved in this not necessarily you) understand this some will continue to be hurt.
> 
> Hell if the earth is that lousy of a conductor, it is actually safer you can hold a ungrounded/hot/energized conductor and stand bare naked on the earth SAFELY.
> 
> SCREW THE GD EARTH... install proper wiring with proper grounding (BONDING) of all metallic parts.


 Absolutly true. That is way more important than the rods.


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## zen (Jun 15, 2009)

slight off the subject,i was wondering how to test ohms on a ground rod or a circut


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## Dennis Alwon (May 9, 2009)

zen said:


> slight off the subject,i was wondering how to test ohms on a ground rod or a circut


To try and vain to keep one thread on topic I will direct you here for your answer


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