Inspector rejected grounding installation for single family service.

[bilbuz53]

Our crew upgraded a single family residential service consisitng of 1-200 amp MBP. The water main was inaccessable so they decided to install 2 ground rods at least 6' apart and 2 seperate runs of #6cu from the bonding bar, 1 to each to each rod.
The Inspector rejected the installation stating that we cannot parallel grounding conductors.

We could have simply jumped the rods together but decided since ther were 2 electrodes required we felt they should be seperate runs.

Im Stumped...

 

[Dennis Alwon]

The inspector is wrong, imo. To be parallel they would have to be electrically connected at both ends (art 310.10(H)(1)--

However I don't see how you can avoid not connecting to the water main. The rods are not a substitute for bonding the water pipes

 

[augie47]

:thumbsup:

 

[bilbuz53]

The inspector is wrong, imo. To be parallel they would have to be electrically connected at both ends (art 310.10(H)(1)--

However I don't see how you can avoid not connecting to the water main. The rods are not a substitute for bonding the water pipes

We did bond the water pipe but could not access the point of entry (5ft rule) so could not be considered as an electrode. (250.52 (A)(1)

 

[jumper]

We did bond the water pipe but could not access the point of entry (5ft rule) so could not be considered as an electrode. (250.52 (A)(1)

While I see your point, I see no exception for not using the water pipe as an electrode if it qualifies. Unlike a CEE, the seems to be no relief because it is unaccessible, so I gather an accessible point within 5 ft. of entering the structure must be made and a connection made.

 

[Smart $]

While I see your point, I see no exception for not using the water pipe as an electrode if it qualifies. Unlike a CEE, the seems to be no relief because it is unaccessible, so I gather an accessible point within 5 ft. of entering the structure must be made and a connection made.

Inaccessible is often (but not always) an excuse for inconvenient. :happyyes:

I have to wonder what the circumstances are. Digging down to the water line on the outside could possibly be the easier access.

In pondering the above, I have to wonder about an instance where the water line penetrates a foundation into a crawl space area below grade. Would the foundation penetration be considered the entry, or where the water line emerges and accessible, say an inner wall to a basement portion. If these were service conductors, they'd be considered outside the building... but there doesn't appear to be any consideration of the sort for water lines.

 

[infinity]

The Inspector rejected the installation stating that we cannot parallel grounding conductors.

Where do you find these guys. :roll:

 

[Ponchik]

Where do you find these guys. :roll:

Not to pick on the OP but IMO a qualified installer should always ask for a code reference when his/her job is turned down. If the inspector does not have a code book I should have my book handy.

I do understand some situation are gray in nature and do depend on interpretation, but still there is room to wiggle.

 

[bilbuz53]

Inaccessible is often (but not always) an excuse for inconvenient. :happyyes:

I have to wonder what the circumstances are. Digging down to the water line on the outside could possibly be the easier access.

In pondering the above, I have to wonder about an instance where the water line penetrates a foundation into a crawl space area below grade. Would the foundation penetration be considered the entry, or where the water line emerges and accessible, say an inner wall to a basement portion. If these were service conductors, they'd be considered outside the building... but there doesn't appear to be any consideration of the sort for water lines.

Lets then assume for this discussion that the water service and piping system is non metallic. We are still required to have 2 grounding electrodes. Then if we run one #6 and jump both ground rods together, is that considered to be one electrode or two electrodes and does it meet the intent or letter of the code. If we run 2 separate runs of # 6cu from the bonding bar to 2 separate ground rods, I believe that this clearly satisfies the intent and letter of the code as having 2 separate electrodes bonded together at the bonding bar. Or am I nutz.... Then the inspector comes in and rejects the job for having grounding conductors in parallel....I am usually ready to ask for the art and section number that he is sighting but I was on the other end of the phone dumbfounded.

 

[jumper]

Lets then assume for this discussion that the water service and piping system is non metallic. We are still required to have 2 grounding electrodes. Then if we run one #6 and jump both ground rods together, is that considered to be one electrode or two electrodes and does it meet the intent or letter of the code. If we run 2 separate runs of # 6cu from the bonding bar to 2 separate ground rods, I believe that this clearly satisfies the intent and letter of the code as having 2 separate electrodes bonded together at the bonding bar. Or am I nutz.... Then the inspector comes in and rejects the job for having grounding conductors in parallel....I am usually ready to ask for the art and section number that he is sighting but I was on the other end of the phone dumbfounded.

2 rods are 2 electrodes and you can have one GEC to both or a single GEC to each, both satisfy the NEC.

 

[bilbuz53]

2 rods are 2 electrodes and you can have one GEC to both or a single GEC to each, both satisfy the NEC.

I agree with you and that had been my thought all along until one of my employees who just passed his master exam mentioned that they need to be separate in order to be considered as 2 separate electrodes. Most of the services we do are bonded to the H20 main along with a driven electrode so the question had not come up.
I received my training and license in the 70s and have tried to keep up with the code but as you know it takes great effort and not faced with it until were turned down which is not often. We need to know more than the inspectors anyway.
Thanks,

 

[Smart $]

2 rods are 2 electrodes and you can have one GEC to both or a single GEC to each, both satisfy the NEC.

I agree.

Perhaps inspector is thinking the rods are jumpered... or GEC is a loop.

@bilbuz53

Were acorns completely visible, top and bottom, during inspection?​

 

[bilbuz53]

I agree.

Perhaps inspector is thinking the rods are jumpered... or GEC is a loop.

@bilbuz53

Were acorns completely visible, top and bottom, during inspection?​

Good question. I assume that the acorns were visible with the divot ready to be pushed into the hole. The inspector did not ask if it was a loop which I'm sure it is not.

 

[iwire]

We did bond the water pipe but could not access the point of entry (5ft rule) so could not be considered as an electrode. (250.52 (A)(1)

Here that would be a fail.

They would require us to access it.

 

[infinity]

Lets then assume for this discussion that the water service and piping system is non metallic. We are still required to have 2 grounding electrodes. Then if we run one #6 and jump both ground rods together, is that considered to be one electrode or two electrodes and does it meet the intent or letter of the code. If we run 2 separate runs of # 6cu from the bonding bar to 2 separate ground rods, I believe that this clearly satisfies the intent and letter of the code as having 2 separate electrodes bonded together at the bonding bar. Or am I nutz.... Then the inspector comes in and rejects the job for having grounding conductors in parallel....I am usually ready to ask for the art and section number that he is sighting but I was on the other end of the phone dumbfounded.

If you have non-metallic water piping system why do you need two electrodes? The NEC only requires one. If you're using ground rod(s) a single rod must have a resistance of 25 ohms or less to qualify as an electrode. Supplementing it with another rod negates the 25 ohm requirement.

 

[qcroanoke]

2 rods are 2 electrodes and you can have one GEC to both or a single GEC to each, both satisfy the NEC.

Glad to hear that!
I just had one pass that was two rods, one GEC.

 

[GoldDigger]

Glad to hear that!
I just had one pass that was two rods, one GEC.

Technically, there is actually only one GEC which goes to the nearest rod, and the other wire or extension of the same wire is actually a bonding jumper connecting the second electrode to the GEC.
That is actually important, since it means that the extension to the second rod does not have to be continuous or irreversibly spliced.

 

[kwired]

Though some of this has been mentioned here is some grounding electrode system 101.

Starting with 250.50 which starts out with:"All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system."

(A)(1) through (A)(7) mentions these items:
(1) Metal Underground Water Pipe.
(2) Metal Frame of the Building or Structure.
(3) Concrete-Encased Electrode.
(4) Ground Ring.
(5) Rod and Pipe Electrodes.
(6) Other Listed Electrodes.
(7) Plate Electrodes.
(I left out the details that followed list items)
What that means is if an item in the list exists, you must use it as a grounding electrode.

The next part of 250.50 says: Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used. That basically means if there is no water pipe, no structural steel, and no concrete encased elecrode, then you must use one of the other elecrodes mentioned - and/or item (A)(8) which is Other Local Metal Underground Systems or Structures.

The most common item chosen is ground rods but any item in (A)(4) - (A)(8) is acceptable.

As has been mentioned the ground rod option does have that 25 ohm rule - and is written so that you now must prove there is 25 ohms or less or use the second rod. Most just use the second rod as they have no reliable method to prove the resistance of a rod, and it is simpler and generally cost less anyway. If not using a rod - you don't need to prove electrode resistance.

It is permissible to run a single conductor to each individual electrode, or it is permissible to run the GEC to one electrode, and the conductor run to each additional electrode is called a bonding jumper, and you can "daisy chain" from electrode to electrode.

 

[macmikeman]

I bet your metallic water pipe is not as impossible to access as you think. The 5 foot rule is clearly for interior connections. If you connect your gec to a qualifying metal water pipe on the exterior of the structure you don't have any 5 foot restrictions, regardless of the millions of misinterpretations of the NEC regarding that factor.

 

[jxofaltrds]

Our crew upgraded a single family residential service consisitng of 1-200 amp MBP. The water main was inaccessable so they decided to install 2 ground rods at least 6' apart and 2 seperate runs of #6cu from the bonding bar, 1 to each to each rod.
The Inspector rejected the installation stating that we cannot parallel grounding conductors.

We could have simply jumped the rods together but decided since ther were 2 electrodes required we felt they should be seperate runs.

Im Stumped...

If the 2nd rod is to augment the first he is correct. (I don't have the 2014 - so if it reads different would someone post it).

EDIT - wrong

2011 changes

(2) Supplemental Electrode Required. A single rod, pipe,
or plate electrode shall be supplemented by an additional
electrode of a type specified in 250.52(A)(2) through
(A)(8). The supplemental electrode shall be permitted to be
bonded to one of the following:
(1) Rod, pipe, or plate electrode
(2) Grounding electrode conductor
(3) Grounded service-entrance conductor
(4) Nonflexible grounded service raceway
(5) Any grounded service enclosure