Grounding Electrode Conductor-Continuous

[Trey4U]

250.64(C) requires the grounding electrode conductor(s) to be installed in one continuous length without a splice or joint....

If the resistance to ground of the single electrode is less than 25 ohms it shall be augmented by one additional electrode. If a second electrode is required, does 250.64(C) still apply? I'm arguing the point that only the first electrode is required to have a grounding electrode conductor that is unspliced and that you don't have to replace the first conductor with one that goes all the way from the panel to the second electrode. I'm thinking the conductor to the second electrode from the first is a bonding jumper and not a grounding electrode conductor. I'm in Afghanistan so we're using the 2008 NEC. Any comments?

 

[augie47]

I have seen it enforced and argued both ways. Most inspectors with whom I am acquainted feel the second rod is a second electrode and allow the two to be connected by a conductor that is not continuous with the original conductor as long as the terminations are made properly.

 

[Canton]

I have seen it enforced and argued both ways. Most inspectors with whom I am acquainted feel the second rod is a second electrode and allow the two to be connected by a conductor that is not continuous with the original conductor as long as the terminations are made properly.

i wish you were here i just got busted on this today....i had to go back and pull a continuos #6

 

[infinity]

I agree with Mike on this one:

 

[jumper]

i wish you were here i just got busted on this today....i had to go back and pull a continuos #6

Your inspector was incorrect IMHO.

 

[ceb58]

i wish you were here i just got busted on this today....i had to go back and pull a continuos #6

I have one inspector that see's it the same. Even when you show him the articles that back up the fact the second connection is a bonding jumper. So I know what he wants and I will do the one continuous wire. On a personal note I would rather have the one continuous wire, plus is saves the cost of an extra acorn clamp.

 

[Smart $]

And how do you "bonding conductor" proponents get around 250.68(C)?

(C) Grounding Electrode Connections. Grounding electrode
conductors and bonding jumpers shall be permitted to
be connected at the following locations and used to extend
the connection to an electrode(s):

(1) Interior metal water piping located not more than 1.52 m
(5 ft) from the point of entrance to the building shall be
permitted to be used as a conductor to interconnect electrodes
that are part of the grounding electrode system.

Exception: In industrial, commercial, and institutional buildings
or structures, if conditions of maintenance and supervision
ensure that only qualified persons service the installation,
interior metal water piping located more than 1.52 m (5 ft)
from the point of entrance to the building shall be permitted as
a bonding conductor to interconnect electrodes that are part
of the grounding electrode system, or as a grounding electrode
conductor, if the entire length, other than short sections passing
perpendicularly through walls, floors, or ceilings, of the
interior metal water pipe that is being used for the conductor
is exposed.

(2) The metal structural frame of a building shall be permitted
to be used as a conductor to interconnect electrodes
that are part of the grounding electrode system,
or as a grounding electrode conductor.

(3) A concrete-encased electrode of either the conductor
type, reinforcing rod or bar installed in accordance with
250.52(A)(3) extended from its location within the concrete
to an accessible location above the concrete shall
be permitted.

 

[DrSparks]

Bonding vs grounding

Bonding vs grounding

The purpose of bonding is to equalize potential of electrically-connected metal parts, the grounded conductor, and the structure of the building. The purpose of the GEC is to provide a low-resistance path to ground. They serve very different purposes. Code interpretation set aside, the connection between two ground rods is part of the GEC and a mechanical connection, rather than a continuous wire or being exothermically fused, offers much higher resistance, imho.

 

[George Stolz]

And how do you "bonding conductor" proponents get around 250.68(C)?

What's the problem? :?

 

[George Stolz]

Code interpretation set aside, the connection between two ground rods is part of the GEC and a mechanical connection, rather than a continuous wire or being exothermically fused, offers much higher resistance, imho.

Care to prove that? Mechanical connections are listed for grounding electrode connections, so they must be good enough, no?

 

[Smart $]

What's the problem? :?

I don't see ground rod mentioned as a location from which connection to an electrode can be extended...

 

[augie47]

And how do you "bonding conductor" proponents get around 250.68(C)?

How about 250.64(F)

 

[George Stolz]

I don't see ground rod mentioned as a location from which connection to an electrode can be extended...

You're not "extending a connection", you're connecting directly to an electrode. There has been no controversy about that connection for a long time.

 

[Smart $]

How about 250.64(F)

See below...

You're not "extending a connection", you're connecting directly to an electrode. There has been no controversy about that connection for a long time.

I know that, but does that make it correct? I feel like you're giving me the "we've always done it that way" reply... :huh:

Please refer to Article 100 definitions of Grounding Electrode Conductor and Bonding Conductor or Jumper.

If bonding jumpers are permitted to connect any one grounding electrode to another, what is the purpose of 250.64(C) and 250.68(C)?

Grounding requirements are complex. Could be why Article 250 is the largest in the Code. In some cases, we take one little part of a section, say that applies exclusively, and be compliant. In other cases, several sections may apply and we can't (or shouldn't) just take one section and say it applies exclusively.

 

[don_resqcapt19]

The code could use some work in this area, but it appears to me that where you have multiple grounding electrodes, there is only one grounding electrode conductor that runs between the service equipment and a grounding electrode. The additional grounding electrodes are connected using bonding jumpers.
This is idea is supported by the following code rule.

250.64(F) Installation to Electrode(s). Grounding electrode conductor(s) and bonding jumpers interconnecting grounding electrodes shall be installed in accordance with (1), (2), or (3). The grounding electrode conductor shall be sized for the largest grounding electrode conductor required among all the electrodes connected to it.
(1) The grounding electrode conductor shall be permitted to be run to any convenient grounding electrode available in the grounding electrode system where the other electrode(s), if any, is connected by bonding jumpers that are installed in accordance with 250.53(C).

 

[Smart $]

The code could use some work in this area, but it appears to me that where you have multiple grounding electrodes, there is only one grounding electrode conductor that runs between the service equipment and a grounding electrode. The additional grounding electrodes are connected using bonding jumpers.
This is idea is supported by the following code rule.

I guess I'll go with that... but it seems rather moot to have 250.68(C) if you can interconnect any electrode to another with a bonding jumper, don't you think?

 

[don_resqcapt19]

I guess I'll go with that... but it seems rather moot to have 250.68(C) if you can interconnect any electrode to another with a bonding jumper, don't you think?

I see no real reason for 250.68(C) to even be in the code. It is my opinion that the EGC is much more important to electrical safety than is the GEC and the code does does not require the EGC to be continuous.

 

[George Stolz]

The purpose for 250.68(C) is to offer places to connect GECs and bonding jumpers in close proximity (but not directly) to the business end of electrodes listed in 250.52(A). If you're not connected to a water pipe in the dirt, or a CEE inside the concrete, you missed. 250.68(C) lists "close enough misses."

 

[Smart $]

The purpose for 250.68(C) is to offer places to connect GECs and bonding jumpers in close proximity (but not directly) to the business end of electrodes listed in 250.52(A). If you're not connected to a water pipe in the dirt, or a CEE inside the concrete, you missed. 250.68(C) lists "close enough misses."

I'll accept that explanation