Supplemental Ground Rod Bonding Question

By code they MUST be bonded together. You are seeing the charming consequence of "wye" distribution and a very high impedence grounding media. Your service ground rod is a current carrying conductor and the best you can do is to rediuce gradients with more bonding. I am surprised you have a ground rod at the pool. What kind of pool is it?

It is perfectly acceptable to run the new Grounding Electrode Conductor (GEC) to the existing ground rod by adding an additional acorn clamp to that rod. I strongly recommend that you do not run the new GEC inside your home in order to terminate it. You are much better off if you keep the GEC outside your home. Don't make lightning energy pass through your service equipment enclosure on the way to earth.

I do intend to bond them together. The question is whether (assuming the main ground rod is up to code)using the ground/neutral bus bar inside the main disconnect panel (to bond a supplemental ground system) is OK per NEC as opposed to bonding within the meter can. For sake of argument, I can bond the conductors outside the meter can and the main disconnect panel as well. I just prefer not to bond the supplemental ground system inside the meter can as it requires working within live conductors. (Please re-read my original post for clarity)

The pool ground rod is for the pool pump casing. The pool and pump were added after the house was built.

The new GEC would be bonded inside the main disconnect panel which is outside the house next to the meter can. There will be very little conductor (inductance) between the existing main GEC and the new supplemental GEC. I am not trusting of the 28 year old conductor from the meter can to the existing main GEC and so would not like to rely entirely on direct bonding of that existing ground rod*. Thus I have another conductor I wish to bring inside the main disconnect panel to bond the ground/neutral bus bar.

*If I have work done in future that requires opening the meter can, I may want to replace the old conductor and at that time, I will have the utility company make the connections.

The new GEC would be bonded inside the main disconnect panel which is outside the house next to the meter can. There will be very little conductor (inductance) between the existing main GEC and the new supplemental GEC. I am not trusting of the 28 year old conductor from the meter can to the existing main GEC and so would not like to rely entirely on direct bonding of that existing ground rod*. Thus I have another conductor I wish to bring inside the main disconnect panel to bond the ground/neutral bus bar.

*If I have work done in future that requires opening the meter can, I may want to replace the old conductor and at that time, I will have the utility company make the connections.

The new GEC would be bonded inside the main disconnect panel which is outside the house next to the meter can. There will be very little conductor (inductance) between the existing main GEC and the new supplemental GEC. I am not trusting of the 28 year old conductor from the meter can to the existing main GEC and so would not like to rely entirely on direct bonding of that existing ground rod*. Thus I have another conductor I wish to bring inside the main disconnect panel to bond the ground/neutral bus bar.

*If I have work done in future that requires opening the meter can, I may want to replace the old conductor and at that time, I will have the utility company make the connections.

Putting this into an even simpler context and assuming that I have a single point ground system (albeit many rods), is there anything in the NEC that prevents me from connecting the ground system at two points. 1) within the meter can at the neutral (as existing) and 2) within a short distance away, connecting to the ground.neutral bus bar inside the main disconnect panel.

I can see a case where this may exist to the extreme:

A pole mounted meter can, and some distance away, a house mounted main disconnect panel. Would it not be prudent to have a ground rod at each of those locations?

Bond ALL your grounding electrodes to create your "grounding electrode system". Connect the grounding electrode system via the "grounding electrode conductor" to the service per 250.24. From the 2005 NEC: "(A) System Grounding Connections. A premises wiring system supplied by a grounded ac service shall have a grounding electrode conductor connected to the grounded service conductor, at each service, in accordance with 250.24(A)(1) through (A)(5).

(1) General. The connection shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected at the service disconnecting means."

There is a single grounding electrode conductor - I got the impression that you might be thinking of bringing multiple conductors from the various electrodes into the panel and bonding them there. That's the wrong way - you can't have multiple GEC's.

Ed

Connecting inside the meter can would be more fun. Have someone standing appropriately far away taking pictures to post.

My 1st choice would be to split-bolt the #6 bond wire to the grounding electrode conductor (GEC) in the vicinity of the meter. You sound like you wouldn't like that idea.

The permissible connection locations are in 810.21(F) They include:

- any point on the grounding electrode system (as above)

- metal service raceway (like a ground clamp on EMT above the meter; below the meter more than normal bonding of the pipe is required)

- grounded interior metal water pipe within 5 ft of the building entrance (10 ft min underground metal water service pipe should already be an electrode; else metal interior water pipe should already be bonded)

- the meter enclosure or service disconnect enclosure.

The ground/neutral bar of the service disconnect is not specifically included, but is substantially the same as the last item above (even though the GEC does not land on the bar).

Ask the AHJ?

The bonding wire should run in "as straight a line as practicable" and can be inside or outside.

If the NEC is enforced for dish installs, the installer should have made this bonding run.

I have pretty much satisfied myself that I will have: 1) a single point grounding system. The original ground rods and supplemental ground rods will all be bonded together at ground level and, 2) A redundant ground conductor which will terminate inside the main disconnect panel at the ground bus. I really don't trust the original ground conductor at the meter can and using a split bolt right at the meter can to bond the redundant conductor does not preclude the possibility of the main conductor loosening inside the meter can.