QOD for 04/11/2006

[Richard L. Bennett]

This is one of the real problems that I have with the NEC and codes

In general everything works but the real issue is not that it is legal but is it a good ground

Sorry

Glad as HI we don't have to go this deep

rlb

[Paul W. Abernathy]

Richard,

Because you CAN'T......you simply can't argue with a local AHJ about what they demand. They demand a reliable testing method to determine 25 OHMS or less or simply install the 2nd ground rod.

Now...if you are saying using a volt meter and doing OHMS is reliable to a AHJ inspector....I need to introduce you to some AHJ's...and some very well known AHJ's ( they help write CODE rulings)

Ok....I will take it you are not an electrical contractor.....no problem but their are standards for what testing and requirements will be allowed and most AHJ's have already set up mandates that say regardless of testing they would like (2) ground rods....now I can't tell you why they simply say (2) and then no need to check for OHMS......it is all a matter of "SAFER" is always better with the AHJ.....and 2 is always better than 1 senerio.

Also..look........while I DO care.....I am a contractor and the CODE says I have to do this and that...so I do what the code says I have to do...we always drive (2) rods now....1.) because by the time I pay to spend the extra time debating it...our LARGE hammer drill can drive a ROD down in about 3 minutes.....without me lifting a single sledge hammer...

I do hear ya......but in the scheme of things it takes too much time, not as accurate as the local AHJ would like as it contains to many varibles that can go wrong and in nearly 100% of the cases now the AHJ will still simply say...BUT I WANT TWO RODS.....so it SHALL BE.......

Also......if the building inspector comes and wants (2) rods...do you think me telling him..."Sir, I tested the one and it was fine " will make him happy.

Been Their...lol....Done...That....My Brother tries it all the time.....he even has the tester ( which again you can get for about $ 180.00 )...but because the AHJ comes at different times and he is not always their....he is not going to come back to save a few bucks on a ground rod....and the AHJ's atleast here in VA....all demand (2) rods now.....so no point in testing them...

Not jumpin on ya brother.....just telling you how it is in the field everyday

UPDATE- I am editing this because I wanted to place the link to the earth ground resistance test kit my brother has.....he got it on e-bay for around 180.00 but I see they sell for 199.00 new anyway..

http://www.globaltestsupply.com/test...Tester_Kit.cfm

P.S.....He just informed me he DID use it for a local AHJ in Nelson County and the AHJ said he still would not accept it.....he MUST install the 2nd Rod.......just wanted to post that for ya.

[David A. Delaney]

Here in the great state of WV, the three largest electricity providers REQUIRE two ground rods (1/2" copper or 5/8" copper clad) be installed within 6' of one another. All of us who inspect electrical services for connection do not have the liability of measuring resistance to ground, because that utility companies supercede the NEC, which keeps me from being just another a--hole AHJ. Of course, the contractors find other reasons to dislike me .

[Richard L. Bennett]

10-4 Paul and Dave

When God speaks we have got to do what he says

I am still thinking about older homes where the grounding system is broke

If we SEE a problem we will note it -- Just thinking and that is dangerous

If it is broke as noted in the inspection (just like an outlet) -- noted and call the electrical contractor

Just thinking

I find that digging a hole looking for a ground rod INVACEIVE and too much work -- I know in my heart that the rod and clamp are history but I am not going to go that far. I do note that could not find the ground rod and if I can pull the wire out of the dirt I note that it was not attached to a ground rod - safety issue

I also note if the phone and cable TV is connected to grounded

I think we are all on the same page here -- IS IT SAFE??

Paul the electrical storms are so bad down here we are seeing TVSS units installed outside at the main electrical disconnect point and at the disconnect for the HVAC.

I have also seen them blown up like someone shot them with a rifle


Good grounding is a very good thing

rlb

[Paul W. Abernathy]

Richard,

Since someone whom we all KNOW....must have cried and moaned about a post from EC & M online....here is the link for everyone on the 25 ohms or less story I thought you all would like.....

Gesssh OLD PEOPLE.....

http://www.ecmweb.com/mag/electric_c...ess/index.html

[Gerry Beaumont]

Hi to all,

why would anyone have an issue with a web page available in the public domain with both a save and print function on it??

Couresty ECN www.ecmweb.com

Find out why the National Electrical Code "25 ohms or less" rule may have less to do with power quality than you think.
Nearly all electricians and electrical inspectors are familiar with the National Electrical Code requirement in Sec. 250-54, which requires the resistance to ground of a single-made electrode (e.g., ground rod) to be 25 ohms or less. Unfortunately, it seems many electrical professionals don't actually test the grounding electrode system (GES) to ensure they're meeting this requirement. Even fewer of you feel testing the earth ground system is worthwhile. From a power quality perspective, you may be right.
A GES provides:
• A zero-volt reference for the supplied or derived power systems.
• A path to dissipate lightning or fault current (for higher voltage systems).
• A path for the dissipation of electrostatic currents.
A GES consists of two components: the grounding electrode conductor (GEC) and the grounding electrode.
You can choose a bare or insulated GEC (sized per Table 250-66) in copper or aluminum. The GEC connects the grounding electrode to the grounded circuit conductor, the equipment-grounding conductor, or both, at the main service equipment or the source of a separately derived system.
The most common types of grounding electrodes (identified by Sec. 250-50 and 250-52) are:
• Structural steel
• Metal underground water pipe
• Ground ring
• Ground rods
How to test. You should measure the resistance of an electrode with respect to the surrounding soil in the area. You can only do this by using the fall-of-potential method with a three-terminal, earth ground resistance tester. To properly test the resistance of a GES, you must follow some simple rules:
1. Disconnect the electrode under test from the rest of the electrical system. Considering this, it is not possible to test the grounding electrode system in nearly all circumstances.
2. Don't use a meter that injects DC current into the ground rod. Do not use standard VOMs.
3. Don't perform test measurements if the current on a GES is greater than 5A.
Contrary to popular belief, clamp-on earth ground resistance testers can be inaccurate in field applications. These testers require a low-resistance feedback loop with adequate spacing between electrode systems to provide meaningful readings. Many people often add a high resistance (caused by loose connections in the feedback loop) to the displayed value of the meter. Also, inadequate spacing between electrodes results in the meter only making a comparative bonding test, which almost always results in a low-resistance value.
Why do I need to reach 25 ohms? The most credible answer to this question is: 25 ohms is a reasonable value to strive for, given the average soil resistivity for most regions of the United States. Keep in mind, however, that 25 ohms is not a requirement when you install multiple electrodes. This is only a requirement for single-made electrodes, per Sec. 250-56. If you drive the first rod and get a resistance reading greater than 25 ohms, the NEC allows you to drive an additional rod 6 ft away from the first rod.
Let's say, for example, you drive a ground rod into the soil, but instead of testing that rod to see if it meets the 25-ohm criteria you drive the second. Once the two rods bond together, consider the GES complete. But if you don't take a measurement, how do you know your installation meets Code?
Reality check. In most commercial and industrial low-voltage power systems, technicians do not perform earth ground resistance testing. But this shouldn't surprise you. An informal poll of 50 electricians found only four performed earth ground testing in the past. The reasons cited for not testing were:
• The testers were too expensive.
• The test was too confusing and took too much time.
• Two rods are good enough (most common response).
Impact of power quality. Believe it or not, nearly all electronic equipment will operate properly without the benefit of a low-resistance GES. Power quality site surveys have shown that in situations where the grounding electrode resistance is between 5 ohms and 105 ohms, it doesn't affect equipment. However, you can trace most problems to poor quality connections on the equipment-grounding system. Therefore, you should pay less attention to the GES measurement and more to the impedance of the equipment-grounding system and the verification of low-resistance bonding connections between grounding planes.
What's the lesson here? Spend less time on the testing and qualification of the GES resistance and more time checking the bonding between locations and the equipment-grounding conductor impedance.

Regards

Gerry

[Paul W. Abernathy]

EXACTLY.....I tell you why.....because BOOK NERDS know nothing about working electricity in the REAL WORLD so they complain and cry and whine to get posts removed........

I tell you...the NEXT post of mine that is removed because an old man does not like it.......Can KISS my butt goodbye from helping NACHI at all....

[Paul W. Abernathy]

Amazing.......Truly Amazing the level some will drop....

[Richard L. Bennett]

Paul

Some how I have lost the objective -- I thought we were on the same page

Have I posted something that you think is out of line.? I agree that the building inspector is god and if he wants 3 ground rods hey lets pound them in. Where I am still thinking is on older homes and I am still thinking.

Gerrys posting about DC or AC testing of ground resistance or impedance is another subject.

My posting on another thread is more related to your own home as a weekend home owner trying to make your home a safe place to live

Install or repair your ground system

Hay if I said something wrong I am sorry -- and if your can't take the apologize then KM*****

Do we understand each other??

I really would like to keep this to fact and not to emotion

Am I on the same page that you are on or should I be on a different thread???

BTW I thank your again to the test equipment link -- I think is is better than a SURETEST

rlb

[Paul W. Abernathy]

lol....NOOOOOO...not you Richard.........

I posted a interesting article for you......JUST for you and SOMEONE ..I wont call names cried and complained to NACHI to have it removed because of copyright fears...BUT it was NOTHING to fear...hell anyone could download it....

lol.....I dont want to kiss you ***** fella........if I dont like something you say TRUST me I will tell ya.......lol....had nothing to do with you...lol

[Richard L. Bennett]

10-4 Paul

Have a good day I understand

Thanks for the PM -- It made my day


rlb

[Paul W. Abernathy]

What is scary...is even though HI's dont test it......should know it when looking at the grounding system...and over 40% got this one wrong......OUCH....

Ok........guys come to OHIO.....thehehehehe......WE gonna learn some stuff...and Git Er Done......

[jtedesco1]

AEMC
Ground resistance Earth testers
www.omnicontrols.comMegabras
High-end megohmmeters at affordable prices. Up to 20kV test voltages.
www.megabras.comGrounding Systems
CADWELD grounding materials, ERITECH ground rods, accessories
www.erico.com

[jtedesco1]

Hey Paul

Who complained? Probably was someone from Arizona or California?

I post most of my articles from EC&M and no one has a problem with that so far why here are a few:

NACHI electrical trainer's latest articles.

NACHI electrical trainer Joe Tedesco has written some great articles. Enjoy:

http://www.nachi.org/documents/304ecm15.pdf
http://www.nachi.org/documents/305ecm15.pdf
http://www.nachi.org/documents/305ecm30.pdf
http://www.nachi.org/documents/306ecm15.pdf
http://www.nachi.org/documents/306ecm30.pdf
http://www.nachi.org/documents/308ecm15.pdf
http://www.nachi.org/documents/308ecm30.pdf
http://www.nachi.org/tenguidelines.htm

About NACHI's Joe Tedesco.

Thanks Joe!

[Timothy J. Gardner]

Paul,

I sometimes answer wrong to see if I can suck someone in that views the poll before voting. OOOPS, did I say that?

tg