Grd. rod question

[infinity]

The farther apart the better but as mentioned 6' is the minimum. This is what the NEC tells us when the rod are longer than 8':

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)(4) through (A)(8). 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.
FPN: The paralleling efficiency of rods longer than 2.5 m (8 ft) is improved by spacing greater than 1.8 m (6 ft).

 

[hillbilly1]

But why put them that close that you get into that situation. I usually drive one and use the other 8' rod as a measure. Minimum 6' but nothing stops you from going 8' or more. In fact the further apart the better is what I understand.

That's what I do too, makes it easy to conform to the distance reg.

 

[Hv&Lv]

I have watched electricians and helpers pull a tape measure out to check the distance. I can't tell you how many have told me that the 6' rule is the maximum and minimum. If I use an additional rod, I normally drive one rod to depth, then measure the distance with the next rod. This way my rods are 8' apart.

Haven't failed for distance apart, but did fail one because the rods were driven to grade.(maybe slightly below)

 

[renosteinke]

"The farther apart the better"

Just a minor quibble here ...

I am not objecting to placing the rods farther apart, and you are certainly allowed to do so .... but that statement misrepresents the data presented in the "American Electricians' Handbook."

A look at the data shows that the second ground rod does work better, the farther it is apart from the first - but that there is very little improvement after six feet of spacing. You've pretty much reached the point of dimishing returns, if not an absolute 'limit.'

I draw our attention to this detail, lest some 'more is better' mindset be inspired to attempt to legislate a different distance.

This distance, btw, is for electrodes bonded together as part of the SAME system. For example, the water pipe entering a house, and the ground rod at the panel. It does not apply to DIFFERENT systems- like, say, the ground rod for the house and the ground rod of the neighbor's house, or the utility pole between them.

 

[infinity]

This distance, btw, is for electrodes bonded together as part of the SAME system. For example, the water pipe entering a house, and the ground rod at the panel. It does not apply to DIFFERENT systems- like, say, the ground rod for the house and the ground rod of the neighbor's house, or the utility pole between them.

Where does it say that?

 

[Fulthrotl]

My helper said he was useing up the little pieces of #6 on the truck. Thier was enough in the extra bent over to go 6'1". So that's what we ended up doing.
Still don't know where the inspector got the ideal it was the wrong rod. His quote " Use the correct type of rods"

ok... there are some local codes, like huntington beach for example...

stainless steel ground rods, 8' long x 5/8" min. about $80.
no city around HB requires stainless steel ground rods...
and hb requires stainless, but they don't specify "type 304"
or whatever... so the home desperates here sell "stainless"
that has enough nickel in it, to make it shiny.

but, "correct type"? perhaps if you fashioned it into a hoop,
it could be a circular type?

 

[renosteinke]

"Where does it say that?"

Does it really have to be spelled out? It 'says' that in the way the measurements were made.

Again, look at the data upon which the code is based. The American Electricians' handbook details the change in ground resistance when a rod is added to an existing rod; by definition they need to be connected. If there is no connection, there is no way that one rod could affect another.

Or, look at it this way: when the cable guy banged in his puny little rod on the opposite side of the house from the electrical service ... and made no connection to the existing ground rod .... was he actually making it better. by having it so far from the existing rod? That's absurd, on the face of it.

Yet another way to consider things ... let's assume, for illustration, that the rod for the house is located right next to the rod for the PoCo transformer on the pole ... and that the soil is very conductive. Have we made the ground path better - or worse? I would assert that for the different systems, things are improved by proximity - while, as shown in the AEH, rods in the same system do better with greater spacing. If this seems confusing, just remember: "lost" electricity only wants to go "home" to its' transformer.

 

[KVA]

shall not be less than 1.83 m
(6 ft) from any other electrode


You cant be under 6' apart. I never understood why people put rods at exactly 6 ft apart? Just do 8 ft. that way you won't be too close.

A lot of people read this wrong and think 6ft apart is the MAX spacing.

 

[infinity]

"Where does it say that?"

Does it really have to be spelled out? It 'says' that in the way the measurements were made.

Again, look at the data upon which the code is based. The American Electricians' handbook details the change in ground resistance when a rod is added to an existing rod; by definition they need to be connected. If there is no connection, there is no way that one rod could affect another.

Or, look at it this way: when the cable guy banged in his puny little rod on the opposite side of the house from the electrical service ... and made no connection to the existing ground rod .... was he actually making it better. by having it so far from the existing rod? That's absurd, on the face of it.

Yet another way to consider things ... let's assume, for illustration, that the rod for the house is located right next to the rod for the PoCo transformer on the pole ... and that the soil is very conductive. Have we made the ground path better - or worse? I would assert that for the different systems, things are improved by proximity - while, as shown in the AEH, rods in the same system do better with greater spacing. If this seems confusing, just remember: "lost" electricity only wants to go "home" to its' transformer.

I don't see a code section in your post to backup what you're saying. If the different electrodes are from the same system they do not require 6' of separation. Is a CEE usually more than 6' from the water pipe?

 

[Buck Parrish]

My problem was Lowes sells 1/2" rods marked as 5/8 ths". You can hardly tell it unless you have a 5/8 ths rod to compare it to. They are the copper clad silvery looking rod.
They called the manufacture, they say thier 5/8 ths. I'll go by thier today to try to get more info.

 

[renosteinke]

Infinity, are you trying to stir the pot? Maybe take a moment to actually read ....

Not in the NEC ... well, golly, maybe because I identified, several times, my source as the "American Electricians' Handbook." That's an actual book title, and not a slang term for the NEC.

Though, speaking of the NEC ... oddly enough, the 6 ft. spacing is mentioned specifically in reference to ground rods. This sort of makes clear that they're not discussing ground plates, ground rings, Ufers, or any other sort of electrode. Note that ground rods are the only type of electrode with the 25 ohm requirement.

Are you really going to claim that you 'understood' my remarks about electrodes on the same system as referring to a ground rod / ufer combination? Now, there's a unicorn! One need not meet the 25 Ohm criteria with a ufer, so what's the point of the ground rod?

Still, let's speculate ... what if you had a ufer, and your metal water pipe was (as it would almost have to be) within the six ft. distance? Let's look at the data in the AEH .... what does that tell us? It tells us that there is less improvement in the ground resistance the closer the two electrodes are ... not that they're ineffective, just that they're not improving things.

Assume for a moment that your Ufer measured more than 25 ohms. Bonding the water pipe that passes right through the ufer would result in zero change to that 25 ohm figure. What if that water pipe went on for miles? Well, we're beyond the six foot mark then, are we not?

Though .... looking at Mr. Ufers' data ..... I expect that even miles of water pipe would not improve things a bit, until that pipe entered some conductive soil. It's THAT hard to improve upon the Ufer.

Net result is that, whatever the type of electrode, you're not able to count it as 'another' electrode in your attempt to meet the 25 ohm requirement unless it's six ft. away. You're back to having to either document the resistance as being less than 25 ohms, or having to use another type of electrode. Since your CEE is another type of electrode, the 25 ohm requirement does not apply.

 

[infinity]

Infinity, are you trying to stir the pot? Maybe take a moment to actually read ....

Not in the NEC ... well, golly, maybe because I identified, several times, my source as the "American Electricians' Handbook." That's an actual book title, and not a slang term for the NEC.

Though, speaking of the NEC ... oddly enough, the 6 ft. spacing is mentioned specifically in reference to ground rods. This sort of makes clear that they're not discussing ground plates, ground rings, Ufers, or any other sort of electrode. Note that ground rods are the only type of electrode with the 25 ohm requirement.

Are you really going to claim that you 'understood' my remarks about electrodes on the same system as referring to a ground rod / ufer combination? Now, there's a unicorn! One need not meet the 25 Ohm criteria with a ufer, so what's the point of the ground rod?

Still, let's speculate ... what if you had a ufer, and your metal water pipe was (as it would almost have to be) within the six ft. distance? Let's look at the data in the AEH .... what does that tell us? It tells us that there is less improvement in the ground resistance the closer the two electrodes are ... not that they're ineffective, just that they're not improving things.

Assume for a moment that your Ufer measured more than 25 ohms. Bonding the water pipe that passes right through the ufer would result in zero change to that 25 ohm figure. What if that water pipe went on for miles? Well, we're beyond the six foot mark then, are we not?

Though .... looking at Mr. Ufers' data ..... I expect that even miles of water pipe would not improve things a bit, until that pipe entered some conductive soil. It's THAT hard to improve upon the Ufer.

Net result is that, whatever the type of electrode, you're not able to count it as 'another' electrode in your attempt to meet the 25 ohm requirement unless it's six ft. away. You're back to having to either document the resistance as being less than 25 ohms, or having to use another type of electrode. Since your CEE is another type of electrode, the 25 ohm requirement does not apply.

Not stirring the pot, it's more likely that I misunderstood your previous posts. :slaphead:

I thought that you were saying all different electrodes of the same system require a minimum of 6' of spacing. If you're not saying that then I apologize for not reading more carefully.

 

[Buck Parrish]

This is not Lowes fault, but... My inspection got turned down because Lowes in my area are selling 1/2" grd. rods marked as 5/8ths.
Lowes tried to feed me some baloney about it being listed as 5/8ths. The local inspections guy turned it down. He must have already been familiar with the problem. The only way you can notice that Lowes rods are a half inch is if you get a 5/8ths one from the electrical supply house and put them side by side.

I complained to thier electrical dept. workers. They called the manufacture whom said that they are listed as 5/8ths.
Well, I told them try explaining that to the local inspections office . Mean while I am out of the $22.oo that two rods cost and I have 4 rods in the ground. My question is if thier UL listed as 5/8ths even though thier not. They should be compliant, right ?? :?

 

[infinity]

This is not Lowes fault, but... My inspection got turned down because Lowes in my area are selling 1/2" grd. rods marked as 5/8ths.
Lowes tried to feed me some baloney about it being listed as 5/8ths. The local inspections guy turned it down. He must have already been familiar with the problem. The only way you can notice that Lowes rods are a half inch is if you get a 5/8ths one from the electrical supply house and put them side by side.

I complained to thier electrical dept. workers. They called the manufacture whom said that they are listed as 5/8ths.
Well, I told them try explaining that to the local inspections office . Mean while I am out of the $22.oo that two rods cost and I have 4 rods in the ground. My question is if thier UL listed as 5/8ths even though thier not. They should be compliant, right ?? :?

The rod needs to physically be 5/8 of an inch or larger, if it's only 1/2" it needs to be listed. 5/8" rods or pipe eletrodes do not require listing.

 

[Dennis Alwon]

Sounds like Lowes needs to provide the listing info.

 

[renosteinke]

Rob, I also owe you an apology. My reply was far more curt than it should have been ... I blame it on simple fatigue .... and I grovel abjectly in my shame.

Thank you for being a gent.

 

[Dennis Alwon]

Buck, I went to Lowes and indeed those rods are 1/2" however they are UL listed so whoever turned it down here should not have. There is a UL sticker on the rod however it is about 8" down from the top of the rod.

I complained at Lowes about the fact that they are selling them as 5/8"X8' rods when in fact they are 1/2" rods. We'll see if they do anything about it. They were very appreciative that I brought it to their attention. Unfortunately those labels are made at the Home Offices so they would have to get all stores to change.

FWIW the rods are made by Galvan Industries out of Harrisburg, NC

 

[Dennis Alwon]

Now I have an call into the company since there website does not show a 1/2" x 8' that is listed.

 

[renosteinke]

Not to quibble, Dennis ... BUT ..

Should not the UL marking be deeply stamped into the metal of the rod? I am thinking 'counterfeit' here.

There are undersized rods listed, but they are galvanized, not copper-wrapped.

 

[Dennis Alwon]

Not to quibble, Dennis ... BUT ..

Should not the UL marking be deeply stamped into the metal of the rod? I am thinking 'counterfeit' here.

There are undersized rods listed, but they are galvanized, not copper-wrapped.

The Nec does not state it must be stamped as many UL fixtures have labels. The rods that Galvan sells that are listed and 1/2" are copper coated. I don't see a listed 1/2" gal. rod that is listed.

The person I talked to stated that the Lowes rods are 5/8". They measure 1/2" so I am not sure if this was a mix up or what.