Supplemental Ground Rod Bonding Question

[RFI-EMI-GUY]

I have a house in Florida built in 1980's. There is an underground
service entrance, a meter can and a main disconnect panel which serves
the sub panel in the house as well as a few circuits outside (pool pump
and pool lights). There is a ground rod bonded to the meter can. (main
ground rod)

I recently had a digital satellite antenna installed by Dish. The
installer chose to ground the dish to my pool pump ground rod which
appears to be isolated from the main ground rod.

Due to the poor grounding by the Dish installer, I chose to install a
series or rods around the sides and corner of the house encompassing the
dish installation, pool pump, main electrical service and the
telephone NIC box. (all these items to be bonded together) These ground
rods were spaced about 12 to 16 feet apart and bonded with #6 solid
copper conductor. After installing this supplemental ground system, I
confirmed that several volt differential between the new supplemental
system and the existing main ground rod (of unknown condition). This
test done without bonding the new supplemental system to the existing
main ground system.

It will be far easier for me to bond this new system to the
ground/neutral bus bar inside of the main disconnect panel than to work
inside the meter can. (requiring breaking the seal and working with live
conductors nearby).

Will there be any code violation or concern by attaching this new ground
system to the main panel as described above? Bear in mind, the
ground/neutral bus bar is connected by the neutral conductor to the main
ground in the meter can only a foot away.


--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[Tom Horne]

I have a house in Florida built in 1980's. There is an underground
service entrance, a meter can and a main disconnect panel which serves
the sub panel in the house as well as a few circuits outside (pool pump
and pool lights). There is a ground rod bonded to the meter can. (main
ground rod)

I recently had a digital satellite antenna installed by Dish. The
installer chose to ground the dish to my pool pump ground rod which
appears to be isolated from the main ground rod.

Due to the poor grounding by the Dish installer, I chose to install a
series or rods around the sides and corner of the house encompassing the
dish installation, pool pump, main electrical service and the
telephone NIC box. (all these items to be bonded together) These ground
rods were spaced about 12 to 16 feet apart and bonded with #6 solid
copper conductor. After installing this supplemental ground system, I
confirmed that several volt differential between the new supplemental
system and the existing main ground rod (of unknown condition). This
test done without bonding the new supplemental system to the existing
main ground system.

It will be far easier for me to bond this new system to the
ground/neutral bus bar inside of the main disconnect panel than to work
inside the meter can. (requiring breaking the seal and working with live
conductors nearby).

Will there be any code violation or concern by attaching this new ground
system to the main panel as described above? Bear in mind, the
ground/neutral bus bar is connected by the neutral conductor to the main
ground in the meter can only a foot away.

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.

 

[RFI-EMI-GUY]

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?

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.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

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.

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.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

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.

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.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

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.

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.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

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?


--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[ehsjr]

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

 

[bud--]

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.

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.

 

[RFI-EMI-GUY]

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.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P