Grounding on services

[jerm]

Bare copper #6 wire is ran continuous(meaning NO SPLICES)

The GEC only has to be continuous to the first rod.

I thought you could splice as long as it was "non-reversible?"

Where in 250 does it say that you can/can't splice and when/how? No one citing any Code here.

 

[brother]

I thought you could splice as long as it was "non-reversible?"

Where in 250 does it say that you can/can't splice and when/how? No one citing any Code here.

Ok Im quoting most for my LOCAL area. This is where you can find where you can/cant splice the Grounding Electrode.

In the 2008 code its 250.64 (C) continuous. They did DELETE/modify some of the execptions.

In 2005 code its 250.64 (C) continuous

 

[brother]

Most residential service panels do not have separate ground and neutral busses so the GEC's would both terminate on the same buss.

Most of the 200 amp service panels ive seen for the residential here (especially the Homeline specials/pakage deals with breakers at Home cheapo) do have a NEUTRAL and GROUND buss, with the BONDING jumper already installed. And believe it or not some of the Inspectors are PICKY and they want that #6 from the ground rods ON the GROUND buss and that #4 from the WATER PIPE on the NEUTRAL buss. Not that it make much difference cause they are BONDED together in the main SERVICE panel (neutral and ground buss).

There will no EGC required between the meter and the service panel. What EGC are you referencing?

The reason i call it an EGC (the #6 from the ground rods) because its attached to the Ground buss (Like i said they are picky) and it APPEARS to be SIZED in accordace with 250.122 which is talking about EQUIPMENT GROUNDING CONDUCTORS For raceway and Equipment. The reason I say this even though its a SUPPLEMENTAL ELECTRODE for the metal water pipe is because according to 250.53 (E) it shall NOT be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire even for 200 amp service.

They (inspectors here from what im told) look at it mostly as a 'ground' and thats why they dont like it when people land it on the neutral buss even though the stuff is bonded anyway. So hence i say EGC (#6), even though it does NOT really clear a fault.

Just look at the 2008 code for the 'other buildings' (ie garages)250.32. If you have to drive 2 ground rods you have to ATTACH that Gec (#6 from the rods) to the Ground buss NOT the neutral buss at garage. No neutral /ground bonding there alowed.

I hope this helps clear up any statements made previously.

 

[don_resqcapt19]

Brother,
The conductor from a ground rod is a grounding electrode conductor and not an EGC. It would be sized per 250.66(A) and not from Table 250.66. As far as its connection at the panel it is required to be connected to the neutral. If your panel meets the rule in 250.24(A)(4) the grounding electrode conductors are permitted to be connected to the EGC bar.
Don

 

[wbalsam1]

Brother,
The conductor from a ground rod is a grounding electrode conductor and not an EGC. It would be sized per 250.66(A) and not from Table 250.66. As far as its connection at the panel it is required to be connected to the neutral. If your panel meets the rule in 250.24(A)(4) the grounding electrode conductors are permitted to be connected to the EGC bar.
Don

Don, did you make a "typo" here? I think you meant .122 :smile:

 

[roger]

Wbalsam1, Don did not have a typo, notice he said 250.66(A) not from Table 250.66.


Roger

 

[keesha]

Just wondering if you guys could give me a hand on grounding electrodes for a service residential and commercial. Everyone I ask gives me a different answer and after reading some stuff here most of them have not a clue, or they just like to be told what to do and not learn anything. I am from MA and I'm really not sure even after reading art 250. Just curious about if ground rods have to be in or outside or both, do you have to connect to the meter or can you go ground rods to water pipe to panel etc. I'm just wondering how some of you guys do it thanks for any information you can give me, I really enjoy reading posts etc from electricians that take pride in what they do. Happy New Year.

DD: (edit- residential)

Mass requires a grounding electrode and a supplemental grounding electrode _IF_ the water pipe is used (see NEC 250.53(D)(2)). Two ground rods at least 6 feet apart equals one electrode in this state do to low soil conductivity. Your resistance to ground must be 25ohms or less. If 25ohms is not achievable with 2 rods, additional rods may be required get to an exceptable resistance level. Any of the methods listed in NEC 250.52(A)(1 thru 7) are exceptable. By the way, a metal underground gas pipe is not allowed to be used as a grounding electrode. It must be bonded to the grounding system but not used as the electrode. Also see NEC 250.54, 250.56 and 250.58 for installation requirements.

AS far as bond in or out of the meter can. Only the AHJ can call that.
Old days we whent in the M-can, now just the panel,where it can be inspected.

Now in NH, I have run into the Utility wanting the supplemental in the M-can and the other 1 in the panel.

 

[augie47]

ddubbs,
You see now why you get confusing answers :grin:

 

[haskindm]

Keesha,
Is the 25-ohms a MA ammendment? The NEC does not require 25-ohms or less resistance, just an additional electrode if one rod does not provide a resistance of 25-ohms or less. If MA requires ALL electrodes to be 25-ohms or less I can see some poor apprentice driving allot of rods! If that is the requirement in MA, they need to send someone to a grounding class so that they understand what grounding does and does not do!

 

[brother]

Brother,
The conductor from a ground rod is a grounding electrode conductor and not an EGC. It would be sized per 250.66(A) and not from Table 250.66.

I thought i made that plain in my post. The key word here is APPEARS, NOT that it acually is an egc. I DID say it is a SUPPLEMENTAL ELETRODE, I just call it an EGC cause from what ive seen and been told they (Inspectors)want that #6 landed on the Ground buss bar since the Ground buss bar is bonded to the service enclosure (equipment). Look at my post again.

The reason i call it an EGC (the #6 from the ground rods) because its attached to the Ground buss (Like i said they are picky) and it APPEARS to be SIZED in accordace with 250.122 which is talking about EQUIPMENT GROUNDING CONDUCTORS For raceway and Equipment. The reason I say this even though its a SUPPLEMENTAL ELECTRODE for the metal water pipe is because according to 250.53 (E) it shall NOT be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire even for 200 amp service

As far as its connection at the panel it is required to be connected to the neutral. Don

Generally speaking you are correct, but since the egc is attached to the service enclosure(as pratice we ground the metal enclosure) and the SUPPLEMENTAL ELECTRODE is ALLOWED to be attached to the service enclosure as well, Have a look at 250.53(2) supplemetal Electrode Required

".....The SUPPLEMENTAL ELECTRODE shall be permitted to be bonded to the grounding electrode conductor, the grounded service-entrance conductor, the nonflexible grounded service raceway, or ANY GROUNDED SERVICE ENCLOSURE "

If your panel meets the rule in 250.24(A)(4) the grounding electrode conductors are permitted to be connected to the EGC bar.
Don

I agree with you. 250.24(A)(4) of the 2008 code says

"Main bonding Jumper as Wire or Busbar. Where the main bonding jumper specified in 250.28 is a wire or busbar and is installed from the GROUNDED conductor(NEUTRAL) terminal bar or bus to the EQUIPMENT GROUNDING terminal bar or bus in the SERVICE equipment, the GROUNDING ELECTRODE CONDUCTOR shall be permitted to be connected to the (GROUND BUS), EQUIPMENT GROUNDING terminal bar, or bus to which the main bonding jumper is connected. "

You just made ANOTHER point of MINE, why we placed the #6 from the rods to the Ground bus. CLEARLY the neutral is bonded to the Ground buss at the SERVICE enclosure/panel in residential HOUSE.


Also did you read the last part of my post about the 'other buidlings' ie garage example, under the 2008 Code.

Just look at the 2008 code for the 'other buildings' (ie garages)250.32. If you have to drive 2 ground rods you have to ATTACH that Gec (#6 from the rods) to the Ground buss NOT the neutral buss at garage. No neutral /ground bonding there alowed.

This is one of the reason i say it APPEARS to be more of an Egc even though TECHNICALLY it is NOT. IT IS TECHNICALLY a Gec as that is what i CALLED it here in my Garage example. And besides this is the way the inpectors want it.

So it was not my intent to cause confusion over the Egc, GEC, or neutral termonology. I will keep that in mind in the future.

I do have A question for you , What is the definition of AUXILLIARY Grounding Electrodes (250.54) and SUPPLEMENTAL Electrodes or the real deference between the 2??

 

[keesha]

Keesha,
Is the 25-ohms a MA ammendment? The NEC does not require 25-ohms or less resistance, just an additional electrode if one rod does not provide a resistance of 25-ohms or less. If MA requires ALL electrodes to be 25-ohms or less I can see some poor apprentice driving allot of rods! If that is the requirement in MA, they need to send someone to a grounding class so that they understand what grounding does and does not do!

We require 2 rods,min 6' apart. The rest is the NEC. But now that you call me on it... I can't find the MEC rule....

DOHHHHHHH!!!

 

[iwire]

As far as I know there is no change in MA from the NEC in this section.

You could use one rod but per the NEC you would have to prove the 25 ohms or less with a ground resistance test. If you install two rods you do not have to test at all.

 

[don_resqcapt19]

Brother,
I didn't read you post close enough, but the code does not support the inspectors requirements. The conductor from the supplemental grounding electrode can be landed on the grounded (neutral) conductor terminal bar as well as the locations that you cited.
As far as the other buildings rule in the 2008 code that has nothing to do with the conenction of the grounding electrode conductors in the service panel. Under the 2008 code a grounding connection to the grounded conductor is no longer permitted, but grounding electrodes are required so the conductors from those grounding electrodes must be connected to the equipment grounding bus at the remote building.

I do have A question for you , What is the definition of AUXILLIARY Grounding Electrodes (250.54) and SUPPLEMENTAL Electrodes or the real deference between the 2??

The auxilliary grounding electrode (previously known as the supplementry grounding electrode) is an electrode that is not required by the code. It is only installed because you or the design engineer wants it. The supplemental electrode is required to be installed by the code rules.

 

[keesha]

As far as I know there is no change in MA from the NEC in this section.

You could use one rod but per the NEC you would have to prove the 25 ohms or less with a ground resistance test. If you install two rods you do not have to test at all.

Thanks Bob. Sometimes I think we mix General/standard practice with the ammendments!

Been doing that way so long, I swore I read it somewhere.

Oh well, Just wanted to add to the confusion for the OP!:grin:

edit:#requires a grounding electrode and a supplemental grounding electrode _IF_ the water pipe is used (see NEC 250.53(D)(2)). # This was the main point I was initialy after.

 

[infinity]

The auxilliary grounding electrode (previously known as the supplementry grounding electrode) is an electrode that is not required by the code. It is only installed because you or the design engineer wants it. The supplemental electrode is required to be installed by the code rules.

Is this a 2008 code change? Did someone think that we're too stupid to know the difference between supplemental and supplementary?

 

[iwire]

Is this a 2008 code change? Did someone think that we're too stupid to know the difference between supplemental and supplementary?

Yeah and I think their name is George...


FWIW I thought the use of supplemental and supplementary was confusing and should have been addressed. No reason to make 250 harder then it is.

 

[brother]

Brother,
I didn't read you post close enough, but the code does not support the inspectors requirements. .

I kinda figured you didn't read close enough, no harm done. That is true the NEC doesnt necessarily support the inspectors requirements, But like i said, this is how they want it done. I cant find anything in the LOCAL amendments either to support this requirement. But im sure they have some 'reason' they want it done that way. Maybe to get people into the habit of trying to understand the difference of the ELECTRODES from the water pipe and the ground rods in residential. Who knows.

As far as the other buildings rule in the 2008 code that has nothing to do with the conenction of the grounding electrode conductors in the service panel. .

Im aware of that too. I just used that EXAMPLE to help give an idea of WHY some of us look at gec as an egc in RESIDENTIAL even though its NOT. Also this view is being compounded by the requirements of the inspectors in the service panel as stated above.

Under the 2008 code a grounding connection to the grounded conductor is no longer permitted, but grounding electrodes are required so the conductors from those grounding electrodes must be connected to the equipment grounding bus at the remote building. .

I thought I SAID that. (is there an echo in here?? LOL) sounds like we are on the same page.

Just look at the 2008 code for the 'other buildings' (ie garages)250.32. If you have to drive 2 ground rods you have to ATTACH that Gec (#6 from the rods) to the Ground buss NOT the neutral buss at garage. No neutral /ground bonding there alowed..

The auxilliary grounding electrode (previously known as the supplementry grounding electrode) is an electrode that is not required by the code. It is only installed because you or the design engineer wants it. The supplemental electrode is required to be installed by the code rules.

Thanks for answering the question.

 

[roger]

FWIW I thought the use of supplemental and supplementary was confusing and should have been addressed. No reason to make 250 harder then it is.

I agree, everytime I'd hear supplementary I'd have to stop and think "now is that part of the GES", Auxilliary makes it easy to recognize that this is a non-required electrode verses the required "supplemental" electrode.

Roger

 

[don_resqcapt19]

Trevor,

Is this a 2008 code change? Did someone think that we're too stupid to know the difference between supplemental and supplementary?

Yes, as I recall that was the substantiation for the proposal.
Don

 

[don_resqcapt19]

Brother,

But im sure they have some 'reason' they want it done that way.

It really doesn't matter if they have a reason unless that reason is backed up by the code or a local amendment. A red tag for a non-violation is malicious prosecution.
Don