$500.00 ground rod

[roger]

250.53(D)(2) in on page 209 of the 2005 NEC handbook... My mistakenot a FPN but commentary. I was on my way out the door when I wrote that.
it references 250.56, which spells out 25 ohms to ground.

And what is your point? That is only for one rod, if you drive another one it doesn't matter what the resistance is.

Iwire, when you are done laughing, take a deep breath so that your brain can get some much deprived oxygen. Then, without getting distracted by all the pretty pictures, read 250.4(A)(1).

Rest assured that Bob knows what 250.4(A)(1) says and he understands it.

Here is an illustration that may help you to understand it and why 25 ohms doesn't mean much.

Geeze, I really dont like bickering with my fellow electricians like this. They are the group of people in the trades that I admire the most.. but I also don't like being torn apart by a synical moderator for being right.....

Right about what?

Roger

 

[stickboy1375]

it seems that more than half of the posts on this thread agree as to the importance of ground rods...

I'm very curious what the importance of ground rods are for, I'm just not exactly sure what they are for...

 

[Bulldog1401]

right about the standard being 25 ohms to ground..right about it being wrong to cut down ground rods because they become difficult to drive, and right about the code spelling out what ground rods are for. Electricity (which lightning is) takes the least resistive path to ground. 25ohms to ground may be what the code figures is less resistance than other things..say you touching the metal frame of a stove, etc... If he knows and understands this section of code, then why does it seem to puzzle him so . Nice graphic by the way. One more thing..if it was really not that important, you would not get failed on an inspection for not having one when you need it, would you?

 

[Bulldog1401]

I understand that lightning will melt its way to ground regardless of the impedence of the path in some cases.. but if you are still more resistive than the easier path, then you will be less affected than other things around you.

 

[roger]

right about the standard being 25 ohms to ground..

And what do you think this will do for say a 120 volt circuit? Do you think it will help open an OCPD?

right about it being wrong to cut down ground rods because they become difficult to drive,

And that is not being questioned even if it's more of an ethical issue than an electrical issue. As an aside, if I were driving a 10' rod and cut 2' off, do you think there is a violation?

Electricity (which lightning is) takes the least resistive path to ground.

This is a common misconception by many but, the fact is electricity takes all paths.

25ohms to ground may be what the code figures is less resistance than other things..say you touching the metal frame of a stove, etc... If he knows and understands this section of code, then why does it seem to puzzle him so .

Trust me, he is not confussed.

One more thing..if it was really not that important, you would not get failed on an inspection for not having one when you need it, would you?

Because it's the code, but do you think a white conductor going to a switch is a safety hazzard if it's not reidentified, IMO it's not but it is the code.

Roger

 

[George Stolz]

right about the standard being 25 ohms to ground...

Bulldog, what would you think if I showed you a rejected proposal to the Code Making Panel overseeing Article 250 that proposed for the 25 ohm requirement to be for any number of ground rods (instead of just governing one rod)?

The proposal to make installers pound ground rods until the reading was 25 ohms or less was rejected because it was too restrictive - that was the CMP's substantiation for rejecting it.

One more thing..if it was really not that important, you would not get failed on an inspection for not having one when you need it, would you?

It does not have to be important or safer to be a code violation.

"Code is Code" is a perfectly acceptable reason for an installer or an inspector to operate, but it is not a very good reason for a code to exist.

 

[Rockyd]

Thanks Roger. Attached is a great commentary from the owner of the forum -


Mike,

Just a quick note to thank you for the fine work you and your staff are doing in providing accurate technical information to field personnel. I am a Senior Service Technician with the Department of Transportation, and part of my duties pertains to illumination of our interchange locations across our state.

After reviewing our lighting standards and current installation practices, it was apparent that these standards did not conform to NEC, and they needed to be changed. The problem was that we only provided two conductors out to our 480V tower lights. We did not provide a low impedance path with the capacity to safely carry the maximum ground-fault current likely to be imposed on it [110.10]. But we did drive ground rods next to each of the metal light poles.

Needless to say, this system would not clear a ground-fault and not open the circuit overcurrent protective device. These were changes that needed made not just for code compliance, but the real life issues of maintaining a safe 480V system in a wet location.

Armed with your Grounding and Bonding book, and a copy of the NEC, I met with the Traffic Engineering Section. We covered the relevant code sections and looked at the illustrations provided in your textbook. Then the picture became clear to all what we needed to do.

We revised or standards, practices, and inspections so that our installations now conform to NEC, and allows our maintenance people to safely work on these systems. I want to thank you and your staff once again.

I'm grateful to have the problem resolved and I felt it was important to write to you and let you know that your efforts are far ranging and considerable.

Mike's Comment: I'm pleased to see that my effort regarding the difference between bonding and grounding is actually making a difference, and maybe it will save a life or two. There are way too many unnecessary deaths caused by people contacting energized metal parts that have been grounded to a ground rod, but not bonded to an effective ground-fault path [250.2 and 250.4(A)(5)].

Much of this confusion between grounding and bonding lies with the NEC's definition and use of the term 'ground,' when in fact the application is bonding to an effective ground-fault current path [250.2(A)(3)]. For example, the NEC in 250.86 requires all metal raceways and enclosures to be grounded. Naturally the NEC does not want us to ground the metal parts to the earth to clear a fault.

Note: The NEC's definition of ground is "the connection to the earth, or some body that serves the place of earth" (I wonder what that means).

2008 NEC: A task group appointed by the NEC correlating committee is reviewing the NEC's use of the term ground and grounding, when the intent is bond or bonding to an effective ground-fault current path. I pray that this committee will propose some changes for the 2008 NEC to clarify the required practice.

However, many industry 'old timers' are against changing of the term grounding to bonding. They say, "it's been that way for over 100 years, not need to change now. "My thoughts? Just because it's been wrong for over 100 years, there is no need to subject the next generation of electrical professionals to this confusion.

I wasn't until the early 1990's before I realized that grounding metal parts to the earth serves no purpose in making an installation safe from electric shock from a ground fault. This is because the earth's resistance is so high; it cannot carry enough fault current to trip a 15A breaker.

Example: A 25 ohm resistance ground rod will only carry 4.8A at a 120V ground fault (I = 120V/25 ohms).

For the past 12 years I have been preaching that we must bond metal parts to an effective ground-fault current path [250.2] in accordance with 250.4(A)(3), not ground them to the earth to clear a fault.

Note: The above comments are in reference to 120V, 120/208V, 120/240V, 277/480V, and 347/600V solidly-grounded systems.

*****

Order from here​

Grounding versus Bonding textbook is loaded with detailed color-coded graphics so you can easily differentiate between grounding and bonding. This text gets to the root of all problems associated with grounding and bonding. Subject includes: Circuit and System Grounding, Grounding Electrode System and Grounding Electrode Conductor, Enclosure, Raceway, and Service Cable Grounding, Bonding, Methods of Equipment Grounding, Direct-Current Systems, and Grounding of Systems and Circuits.

Product Code: 05NCT2
ISBN: 1-932685-22-7


Available June, 2005


According to some of the posts, people should be ordering up! I did the course and thought it was quite informative.

 

[Bulldog1401]

Grounding and ground rods

Grounding and ground rods

Let's see, where do we start....

"And what do you think this will do for say a 120 volt circuit? Do you think it will help open an OCPD?"

It is not intended to open an ocpd. It is intened to take spikes, lightning and other anomolies to ground. Dont confuse grounding and bonding.

"And that is not being questioned even if it's more of an ethical issue than an electrical issue. As an aside, if I were driving a 10' rod and cut 2' off, do you think there is a violation?"

Is the 10 foot rod UL listed at 10 feet? It would be listed to have a specific resistance to ground at 10 feet. Then cutting it down would void its listing. Violation.

"This is a common misconception by many but, the fact is electricity takes all paths."

And the majority of it takes the easiest path. If the balance is unable to travel through that path, it finds another way. By maintaining the low impedence to ground it may choose it instead of you.

"Trust me, he is not confussed."

Then he should not act like it.

"Because it's the code, but do you think a white conductor going to a switch is a safety hazzard if it's not reidentified, IMO it's not but it is the code."

That rule is to identify hot conductors in a junction/switch box that are other than black.

 

[Bulldog1401]

I didn't say "code is code" is all the reason you need. I said that code rules have a purpose, and changing them to fit our needs or to be more convenient can be dangerous. You may not know the purpose, but those wiser (and it seems that some forum members here can't concieve that there is anyone wiser than them) do know what can go wrong if you don't follow the rules. You may go an entire career and not see anything go wrong. But then there may be the time when you have to say "Jesus, I never even thought about that happening". Follow the codes.

george...Is the standard not 25 OHMs to ground? I believe it is. Wether you agree or not it is still printed in the book and enforceable.. along with everything that I have stated in this forum...go ahead... say I was right.. come on... you can do it.. by the way, it says that the one rod will be supplimented by one more, not that the hunt will end there...other means to satisfy the requirement could be required by the AHJ..( electrode plates, ground mats, etc...)Not usually, but theoretically yes.. By the way, when roger and I wire wake up are they going to tag off and try to continue to ram the "theres no need for a ground rod" bunk down my throat, or will they possibly see it like many others do??

 

[LarryFine]

It is not intended to open an ocpd. It is intened to take spikes, lightning and other anomolies to ground.

This is precisely where the 25 ohms is meaningless. To me, "two rods regardless" makes more sense than "two rods unless below 25 ohms." The extra contact area and earth area do more to dissipate lightning than 25 ohms ever will.

And the majority of it takes the easiest path. If the balance is unable to travel through that path, it finds another way. By maintaining the low impedence to ground it may choose it instead of you.

It's more accurate to say that the balance of the electricity flows because it found another way, not if. But that only causes more overall current, because of the parallel paths.

Unless the source and its "supply system" have a high impedance, no less current flows through the "main" (i.e., the lowest) resisive pathway because of the existance of another, parallel pathway.

As with any parallel pathways, the current through each is dependent on its impedance and the source voltage. A 120-ohm resistance flows one amp on 120v, regardless of any parallel loads.

In other words, the current through your body is not lessened because of a lower-resistance path in parallel with you, unless that path is able to reduce the voltage across your contact points.

That rule is to identify hot conductors in a junction/switch box that are other than black.

Actually, that rule is to identify white conductors that are other than grounded. In days gone by, the grounded conductor was referred to as the "identified conductor." Being white was one way of doing so.

There are other methods still in use, too, such as the ribbing on lamp cord, the widened slot on receptacles, etc. The rule is that any color other than white (and of course, green) is presumed to be hot.

 

[LarryFine]

by the way, it says that the one rod will be supplimented by one more, not that the hunt will end there...

Yes, it does say that "the hunt will end there," or at least that it may.

By the way, when roger and I wire wake up are they going to tag off and try to continue to ram the "theres no need for a ground rod" bunk down my throat, or will they possibly see it like many others do??

They've never denied the benefits of a grounding electrode system.

 

[Brady Electric]

$500 ground rod

$500 ground rod

Hear we go again not reading or understanding what others are saying in there post. Picking out certain portions of the post and cutting down the Electrician that post it.
ITS GETTING WE NEED A LAWYER TO POST HERE ANYMORE!!!!!!!!!!!!!!!!!!
We all need to remember that about two thousand others read these postings and will probably not ever post a reply because they don't won't to have to defend there thoughts.
What ever happened to trying to help others become better Electricians?????????
BULL DOG 1401 I agree with everything you are saying in your previous post.
I suppose I-Wire and the rest of you would like it if I quit posting. Being a former Marine I don't quit!' but I am getting tired of reading all this bunk! I don't have time to read for thirty minutes everyday. I started coming to this site to learn and to understand what other Electricians were thinking and to learn what problems other Electricians were having and how they solved them. Instead this form has turned into reading and spending time taking up for yourself on what you have posted.
"Everyone else "What Bull Dog posted is how I interpret the code and the reason why we drive ground rods. Its what I have always been taught since I started 35 years ago.
Most of the time I don't agree with the NEC code either but its our so called Bible in the Electrical Trade. (Just do it because the code said so) Just how many times have we heard that??????
A Electrician once told me (if you want to get rich just get something printed in the NEC).
There's allot more I could say but what I say will just be torn down by others. Sure wish we as Brother Electricians could learn to support each other instead of trying to be the one that is right.
I do apologize for the long post but this is what was on my mind after reading how everyone was cutting down Bull Dog 1401.
Not sure if I am going to continue coming to this site or stay away. Guess most of you hope I leave and don't return.
Don't think this is what Mike Holt intended for this form!
I Would end with "Semper Fi" as I always do but some of you don't seem to know what it means!!

 

[iwire]

Brady, do you come here to learn or just to have 'we have always done it that way' re-enforced by others who stopped learning?

You are right there is some miscommunication in this thread.

But this is a code forum and Bulldog has not been able to show anything in the NEC to back his view.

If you go back to bulldogs first post and read from there I think you will find bulldog 'fired the first shot'.

I am not a Marine but I don't run away either.

Peace and read the thread and see who can back their position and who is stuck in the 'it's the way we always done it mode'.

 

[iwire]

right about the standard being 25 ohms to ground.

That is incorrect, once you drive a second rod your done.

The two rods might have 1000 ohms of resistance but your done anyway.

As George pointed out even the people who write the Article 250 have said so.

Would you tell them to go read 250?

right about it being wrong to cut down ground rods because they become difficult to drive,

I don't recall anyone actually disagreeing with that.

The code requires 8' of rod in the ground.

right about the code spelling out what ground rods are for.

If you study what is happening with the code you would know that what the code says in 250.4(A)(1) about 'what ground rods are for' is the subject of much debate.

Electricity (which lightning is) takes the least resistive path to ground.

No, it takes all available paths every time.

25ohms to ground may be what the code figures is less resistance than other things..say you touching the metal frame of a stove, etc...

A ground rod has absolutely nothing to do with protecting people from a shock off a stove.

That is the job of the EGC (4 wire) or Neutral (3 wire) and the bonding jumper at the panel.

If he knows and understands this section of code, then why does it seem to puzzle him so .

Because I have an inquisitive mind, I don't just do things 'cause they are code' I try to learn why it is code.

Yes I follow the code because I am a professional but at the same time I don't blindly accept that the code is always right.

If the NEC was perfect they would not be changing it every three years....OK they would do it for the money new books bring in..

Nice graphic by the way. One more thing..if it was really not that important, you would not get failed on an inspection for not having one when you need it, would you?

You would fail because it's code required.

Not one person has said otherwise.

Now think about it do you think in 16,000 plus posts that this is the first time I have discussed Article 250 and that I have never read it?

That really makes no sense.

When I am posting usually I have the 2005, 2002, 1999 NEC right beside me, I also have the NEC Handbook on CD-ROM and the IAEI 2005 Analysis of Changes.

I am fairly familiar with the NEC.

 

[Bulldog1401]

Larry Fine,

Excellent points, and you have stated them as I intended to, but you did a better job of it.

This is precisely where the 25 ohms is meaningless. To me, "two rods regardless" makes more sense than "two rods unless below 25 ohms." The extra contact area and earth area do more to dissipate lightning than 25 ohms ever will.

"Yes, it does say that "the hunt will end there," or at least that it may."

I think you can tell by my user name and my tendency to swim up current that I am the last person to do anything "because we have always don’t it that way" That is why I endeavor to find out why we do it, or have done it, that way. When you understand that, you can apply the code to other that standard situations, and still have a safe and code compliant install. Which, not only is the right way to do your work, but it also helps you pass your inspections, and complete your contract.

It seems that some here are fixated on fault current. My reference to the frame of a stove was not to illustrate a path for fault current from a malfunction with the stove (or other circuitry) as stated by Iwire that is the job of the bonding wire in your 3 or 4 conductor feed. My point is that its frame, proper bonding and ultimately proper grounding creates a low impedance path to ground. so if you were involved in a lightning strike, the current would rather travel there than through you. Don’t take my last statement out of context. If you were directly struck by lighting, probably not much of this would matter, as 25 ohms to ground would not. I have been twice affected to a minor degree by lightning while working on electric equipment. The flash you see is the largest part of the energy. Lesser energy is dissipated through other objects in the area, and as you travel away from the strike point, the farther away you get, the less things are affected. I was once on a ladder high up on the side of a house working on lighting. A storm quickly blew in and I decided to quickly finish and close up the fixture. putting in the last screw, I saw lightning strike an area that I knew was approx. 3/4 of a mile away. The static electricity from the strike nearly knocked my off of my ladder. No mind you not more than 5-7 minutes earlier, the weather was fine. I would not willingly go aloft during a storm. The energy went through me into the box and back to ground.
I was also in a basement once doing a service call while another storm blew in. No windows. sunny when I went in there. I was tightening down a ground wire on a bus after fixing some handyman wiring and took a pretty good shock. then I heard the thunder a fraction of a second later. The strike was again nearby. I said that’s enough for me today. Not enough energy at my location to create havoc, but enough to hurt someone not properly dressed, (insulated work boots) or ruin the computers in a lot the things in a house (high end fridge, microwave, washer, stove, etc.. etc..) But it didn't. Because the energy, instead of frying the circuitry, had a decent path to ground instead, and took it. By the way, the surge suppressors you are thinking about need a decent ground to operate as well.

I don’t quite have the mechanics of quoting and posting down yet as you may be able to tell...But Iwire, you are incorrect in your statement that I haven’t shown anything in the code to support my views. I have referenced code sections and sited common electrical theory. Several others here have read and understood my postings clearly, and agree with them. I am not here to beat down your ego to prove that I am right.

I have proven that. Maybe it is you that is stuck in the "we have always don’t it that way" rut, in that you can't accept other interpolations of the code.

I have not fired any first shots. I dared bring some of my experience and understanding to this forum, and because you disagree, you have tried repeatedly to impeach my posts. Was the part about "that point in your career" a first shot? I don’t think so. I was stating that not everybody has the same backgrounds and experiences that help form their understanding of code rules and of electricity in general. This is in no way derogatory. It is a fact. I have not seen it all or done it all. Neither have you. I have heard several electricians’ state that they have, only to see them quickly become lost in the details of a conversation. Followed by the I wouldn't know, we never did that way in Toledo. etc..etc..

Brady electric is right. These forums are for learning. That is what mike Holt had in mind. Not a tool to say it is so because I said so, and I know better than you because I am a moderator.

 

[LarryFine]

It does or it may?

"It may" in the sense that it is permissable. Drive two rods and you've met the requirements.

You're certainly allowed to drive as many more as you wish to.

 

[Brady Electric]

$500 ground rod

$500 ground rod

I-Wire started not to reply but I can't help it.
I don't deny that you probably know the code better than anyone I have ever known. Before all this bashing started I enjoyed reading what you Dennis, Larry, and the other old salts on this form had to say.
I never have agreed with the code on the ground rods. Around here everyone that inspects our work takes the grounding of a ground rod serious. I have been turned down before because the second ground rod was under six feet. It was five feet eleven inches. If the house is fed with metal pipe from the street you ground it with #4 bear copper to the panel. Then drive one ground rod with #6 to the meter base. If you have just PVC from the well you drive two grounds. (Seems like everyone interprets the code a different way.) That's why I carry the NEC Code Handbook with me. Pictures say allot more than words. I understand it to say drive one ground rod and the second NOT under six feet from the first one. Once you start driving a ground rod it is too late to start over. So if it will not go any further I cut off the excess if I can't bend it into the ground because I think it is dangerous. I have been told the reason you drive the other ground rod is to get the right ohms. No inspector has a meter to check that. Everyone knows all types of soil conducts electricity different. In sandy soil I bet you need to drive five of more rods to reach the ohms required. Everyone here in N.C. takes the easy out when explaining why the ground rod and say its because the code says so.
I appreciate your answer, it sounded like the old I-Wire answered it and didn't bash me to much just answered with facts.
Not backing down when confronted doesn't make us a better man its just helps our ego. I wish from now own all of us reply in a good way and not bash anyone.
I have been guilty of that to but I have changed. If we clean our own house first its a good start.
Have a GREAT day and continue to post as the I-wire I remember and others will follow. That's the true man being a leader and other will follow.
Semper Fi. Buddy

 

[roger]

Ok, if you guys want to drive multiple rods to try to get to the magical 25 ohms go for it, but the reality is the NEC only requires two.

As far as bashing some one, If asking for back up or pointing out someones incorrect statement or belief constitutes bashing, then hang on for dear life because it's not going to stop with this thread. You either have your Ducks in a row or some one will line them up for you.

Asking for backup or substaiation and / or correcting a myth is not bashing people.

To ignore these things would be a problem.


Roger

 

[roger]

Bulldog, it is not proper etiquette to edit your posts after they have been replied to

Roger

 

[Bulldog1401]

Again, it was not intended that way, it was because I don't have all the mechanics of editing and quoting down just yet. I was not finished posting, and not yet ready to be replied to. My appoligies.