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  #1  
Old 7/22/07, 6:39 PM
Frank L. Bartlo Frank L. Bartlo is offline
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Default Grounding rod connection from meter box

In my last inspection the house had a grounding rod connection from the grounded lug of the meter box, not from the main panel (which had an incomplete water pipe grounding connection, with no jumper across the water meter).

Hoe effective is such a grounding electrode, compared with a grounding rod connection from the main service panel?
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Old 7/22/07, 6:42 PM
Speedy Petey Speedy Petey is offline
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Default Re: Grounding rod connection from meter box

It is just as effective. The GEC can be connected anywhere from the service point at the weatherhead to the main panel/disconnect.

There is a perfect graphic out there. I'll try and find it.
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Old 7/22/07, 6:45 PM
Speedy Petey Speedy Petey is offline
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Default Re: Grounding rod connection from meter box

Check out this image:

http://www.mikeholt.com/onlinetraini...13854601_2.jpg

The service disconnect in the image can also be the main panel.
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Old 7/22/07, 11:45 PM
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Default Re: Grounding rod connection from meter box

Quote:
Originally Posted by fbartlo
with no jumper across the water meter.
There is no requirement for the water meter to have a jumper if the interior water pipes are bonded elsewhere or if the interior water pipes are not total metal pipes.
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Old 7/23/07, 3:00 AM
Frank L. Bartlo Frank L. Bartlo is offline
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Default Re: Grounding rod connection from meter box

Thanks. It makes sense.

Regarding the supplementary grounding connection, and lack of a jumper, I had heard that there could be greater resistance across a water meter than along the pipe, though it does not make sense to me if the meter housing is brass. Obviously not as big a deal if there is a grounding rod comnnection, but I have seen grounding wires cut due to sloppy yard work.

Last edited by fbartlo; 7/24/07 at 12:58 AM..
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Old 7/23/07, 10:24 PM
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Paul W. Abernathy, CMI Paul W. Abernathy, CMI is offline
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Default Re: Grounding rod connection from meter box

Now IF that water meter is PART of the required use of the water piping supply to the house.....in the ground 10' and metal then it has to be the main GE for the system...if they improperly terminated on the supply side of the water meter and it is removable...then it would indeed need a bonding jumper....now if they installed it on the line side of the water meter then it is fine if the system is bonded somewhere else to the interior system as Mike stated...

But lets not forget IF you are adding that ground rod as supplimentals demanded by the NEC® and a water pipe system ( metal ) is suppying the house and meets the requirements it must be your main GES and the rods are supplimental to that.



Paul W. Abernathy
Manager, Electrical Codes & Standards
Encore Wire Corporation

“Promise me you'll always remember: You're braver than you believe, and stronger than you seem, and smarter than you think.” -RIP Dad, Love You!....10/10/2014

Disclaimer - All my posts on this forum are of my own personal opinion and in no way represent the opinions of Encore Wire, or other associations, organizations or affiliations.
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Old 7/23/07, 10:29 PM
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Paul W. Abernathy, CMI Paul W. Abernathy, CMI is offline
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Default Re: Grounding rod connection from meter box

Oh...sorry.....different topic......yes, it is fine to connect to the GES from the meter can ( if the POCO allows it....) some argue it is not accessible when the TAG is on it...but I say if you have a pair of "SNIPS"...anything is accessible when it pertains to meters for the POCO...

Fact is...I put tie wraps on ALL my disconnects to HVAC units and so on....so no one gets their ( little ones )hands inside them...if they need access...."SNIP".......access granted....



Paul W. Abernathy
Manager, Electrical Codes & Standards
Encore Wire Corporation

“Promise me you'll always remember: You're braver than you believe, and stronger than you seem, and smarter than you think.” -RIP Dad, Love You!....10/10/2014

Disclaimer - All my posts on this forum are of my own personal opinion and in no way represent the opinions of Encore Wire, or other associations, organizations or affiliations.
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Old 7/24/07, 1:02 AM
Frank L. Bartlo Frank L. Bartlo is offline
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Default Re: Grounding rod connection from meter box

In this case the supplemental ground was clamped well downstream of the meter, so it would be disconnected if the meter were disconnected.

Side note: in my reports I always caution people about maintaining grounding continuity when updating plumbing if there is a water pipe grounding connection to a galvanized pipe well away from the water meter.
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Old 7/24/07, 6:49 AM
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Default Re: Grounding rod connection from meter box

HAD TO EDIT.....because I think I misunderstood your question...

1.) The connection to the supplimental ground rod should take place within that 5' of the point of entrance of the main GES which would be the water pipe I guess in this case ( or you can run a direct line to the rods as well if you so choose also ).....so they could go from the water pipe to the ground rods for the supplimental but it has to take place within the first 5' otherwise it is not allowed....

Just be sure it was sized correctly to the water pipe.....before it actually goes to the ground rods as well...as # 6 AWG Bare is fine to the ground rod...but not to the water pipe electrode.



Paul W. Abernathy
Manager, Electrical Codes & Standards
Encore Wire Corporation

“Promise me you'll always remember: You're braver than you believe, and stronger than you seem, and smarter than you think.” -RIP Dad, Love You!....10/10/2014

Disclaimer - All my posts on this forum are of my own personal opinion and in no way represent the opinions of Encore Wire, or other associations, organizations or affiliations.

Last edited by pabernathy; 7/24/07 at 8:11 AM..
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  #10  
Old 7/24/07, 8:39 AM
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Default Re: Grounding rod connection from meter box

Let me open this post with the statement of;
I am only trying to ensure a full understanding of what is required when dealing with metal water pipes.
Having been called to check the grounding of metal water pipes I have seen many different scenarios which were code compliant but hard to find.

250.52(A)(1) requires that any metal water pipe in contact with earth for 10 feet or more to be used as the grounding electrode and the point of connection must be made within the first five feet from the point of entry.

240.104(A)(1) requires that any complete metal water piping system installed on or in a building be bonded to the service. This bond in not part of the grounding electrode system and shall be bonded to the service equipment, the grounded (neutral) conductor, the grounding electrode conductor where of sufficient size, or to the grounding electrode.

The bonding jumper mentioned in 250.53(D) (around the meter) is the required bonding jumper in 250.104(A)(1) and is connecting to the grounding electrode (the underground water pipe). It is convenience that lands the bonding jumper on both sides of the meter not a requirement. What is required is that one end land on the grounding electrode (the first five feet) and the other end could land at any accessible point on the metal water pipe up to and including the far end to the hot water pipe.

If I have the grounding electrode conductor installed within the first five feet of the point of entry then I can install another bonding conductor to any point on the interior water pipe back to the panel and still be code compliant.

If there is not 10 feet of metal water pipe in contact with earth then the grounding electrode conductor is not required.
For example; a metal pipe extends only nine feet from the house and non-metallic pipe is installed from that point to the water supply no grounding electrode conductor is required.

How to bond the interior metal water pipes has been the subject of many debates. Just what is to be bonded on the interior and when is it required?
If the metal water pipes are not 100% metal water pipes then the bonding requirement moves to 250.104(B) and the equipment grounding conductor for the circuit likely to energize the pipes can be the bonding conductor.

If there is less than 10 feet of metal water pipe in contact with earth and the interior is not 100% metal water pipe then there is no requirement to connect any conductor to the pipe itself. Any piece of electrical equipment that is connected to the water system will have an equipment grounding conductor that will fulfill the requirements of 250.104(B). If the circuit supplying any equipment connected to the partial metal water pipe does not have an equipment grounding conductor then the requirement to bond would be required.

I will be more than happy to answer any questions on this matter and give references to my opinion. If you would like send me a PM and we can discuss it future through email complete with illustrations.
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Old 7/24/07, 8:45 AM
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Paul W. Abernathy, CMI Paul W. Abernathy, CMI is offline
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Default Re: Grounding rod connection from meter box

Excellent Post Mike....I will only add that 250.68(B) needs to also be considered IF the connection to the water pipe electrode is done incorrectly and at the wrong point....kinda the only portion of my statements I have been talking about...so I wanted to make it clear again...that bonding jumper IS required by 250.68(B) if terminated to the wrong location ( ie: AFTER the water meter if inside the house....)

Here is an image of what I am refering too.....
Attached Thumbnails
grounding-rod-connection-meter-box-250.gif  



Paul W. Abernathy
Manager, Electrical Codes & Standards
Encore Wire Corporation

“Promise me you'll always remember: You're braver than you believe, and stronger than you seem, and smarter than you think.” -RIP Dad, Love You!....10/10/2014

Disclaimer - All my posts on this forum are of my own personal opinion and in no way represent the opinions of Encore Wire, or other associations, organizations or affiliations.

Last edited by pabernathy; 7/24/07 at 8:51 AM..
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Old 7/24/07, 10:24 AM
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Default Re: Grounding rod connection from meter box

I agree Paul that you slide is correct but I think that it is important that it be understood that the bonding jumper can land elsewhere on the system and is not required to be on either side of the water meter.

In this slide the top half shows a metal water pipe that is not being used as an electrode. There is not 10 feet of metal water pipe in contact with earth so there is no requirement for 250.51(A)(1) nor 250.53.

In the bottom half of the slide there is 10 feet in contact with earth so 250.51(A)(1) is required and the bonding jumper required by 250.104(A)(1) and installed by 250.53 is in compliance although it reaches deep into the piping system.

I have been called out on several systems where there was a filtration and softener system installed and the electrical contractor choose to reach past all these systems to install the jumper outlined in 250.53 from the 10 of metal water pipe in contact with earth (the electrode) and the interior metal water piping system outlined in 250.104(A)(1). By making the connection deep into the piping system they have insured that the permanent and effective grounding path as outlined in 250.68 will not be broken in the event that the filter needs changing or maintainence is needed on the softener system.

I have found that some of the slides that are out there today are misleading a lot of people in the electrical trade including electrical inspectors and home inspectors in so much as they think that the interior end of the bonding jumper is required to land just on the other side of the meter itself.

Case in point;
My neighbor had a new well drilled and called for inspection of the new circuit installed to the new well. The electrical inspector insisted that a bonding jumper be installed around the filter and another jumper be installed around the water softener. The new water line from the well was non-metallic and the interior copper water pipes had been repaired and had a lot of PEX installed.

When I talked with the electrical inspector he pulled out a diagram of the bonding jumpers around a meter and was using this as his example on how the bonding was required by 250.53 of the NEC.

After several minutes talking with the electrical inspector he agreed that there was no requirement for any bonding of any type required be the NEC.

I think that it is very important that there be a better understanding of how the installation of the grounding electrode conductor, which is installed for the event of lightning or power surges, and the bonding, which is in the event that the electrical system energizes the pipes, are to be installed.
There seems to be a lot of confusion between the two.
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Old 7/24/07, 11:38 AM
Frank L. Bartlo Frank L. Bartlo is offline
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Default Re: Grounding rod connection from meter box

Good point about the grounding vs. bonding distinction. I should add language about the bonding of the water pipes in case they become energized in my reports.

I was definitely talking about the supplemental grounding electrode here in reference to the water pipe connection, because I have seen grounding rod connections hacked by sloppy yard work, as mentioned above.
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Old 7/24/07, 6:13 PM
mmuehleisen mmuehleisen is offline
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Default Re: Grounding rod connection from meter box

I see homes with the meter can grounded to a driven ground rod and the service panel grounded at the water service entry. The panel is wired correctly. I wanted to verify that this is satisfactory. Thanks for sharing your knowledge.
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Old 7/24/07, 8:52 PM
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Default Re: Grounding rod connection from meter box

Quote:
Originally Posted by mmuehleisen
I see homes with the meter can grounded to a driven ground rod and the service panel grounded at the water service entry. The panel is wired correctly. I wanted to verify that this is satisfactory. Thanks for sharing your knowledge.
This would be a compliant installation and the way that I do 99.9% of my residential installations.
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