Grounding Electrode System Question

[Jerramundi]

Hey all. Hope all is well. Been a minute since I've been on the forum, but alas, I require the collective expertise of this community once again.

A lack of proper grounding came up as part of a customer's home inspection.

The home inspection explicitly calls for "grounding the meter," probably because the inspector is simply used to seeing ground rods at the meter, as am I.
There is also NO GEC to the water main, but that didn't come up in the inspection report.

In this case, the GEC to the water main is EXTREMELY IMPRACTICABLE. Just want clarify that my understanding is correct, that technically, less any explicit requirements from the municipality, two 5/8" ground rods at the meter is sufficient with respect to the NEC.

Standard operating procedure (SOP) in concise verbiage tells me (1) GEC to Water Main, (2) 2 Ground Rods outside at the meter.
It's been SOP for pretty much my entire career.

I understand that if you use the water main, which has a historical basis and serves as a good electrode (if not the best one), it must be supplemented (per code), which is where we arrive at driving a ground rod at the meter, which then has to be further supplemented with a second rod... but that these are not the only approved methods.

 

[tom baker]

Yes you are correct on your SOP, If the water line qualifies as an GE, then it must be used and supplemented with another electrode, which is often a ground rod, or two if the resistance is not less than 25 ohms, or you don't want to test.
Grounding at the meter is not allowed in some areas, as the connection to the GEC must be accessible, when the meter is sealed its not considered accessible.
If the water line does not qualify as an GE, then it still must be bonded if the interior is a metallic water piping system

A simpler way to state your SOP is drive two and go home.

 

[electrofelon]

The only disagreement I have is with your use of the phrase "at the meter". The gec may connect anywhere from the service point up to and including the first disconnecting means. Sometimes the meter is a convenient place to make a g e c connection, sometimes it is not. Some POCOs do not allow a g e c connection there.

 

[Greentagger]

You are required to connect to all available electrodes. If cold water pipingis available and qualifies , you are to use it as an electrode no matter how impractical it is to connect to it

 

[infinity]

The home inspection explicitly calls for "grounding the meter," probably because the inspector is simply used to seeing ground rods at the meter, as am I.
There is also NO GEC to the water main, but that didn't come up in the inspection report.

In this case, the GEC to the water main is EXTREMELY IMPRACTICABLE. Just want clarify that my understanding is correct, that technically, less any explicit requirements from the municipality, two 5/8" ground rods at the meter is sufficient with respect to the NEC.

What exactly is no "grounding at the meter,"? If that's the water meter it would make sense because you stated that there is no GEC to the water pipe. Impracticable or not the water pipe is required to be used as an electrode if it qualifies as one.

 

[Jerramundi]

Yes you are correct on your SOP, If the water line qualifies as an GE, then it must be used and supplemented with another electrode, which is often a ground rod, or two...

Where does it say that the "if the water line qualifies as a GE, then it MUST be used?"
I understand it as one option of many, but common practice for various, good reasons.

Grounding at the meter is not allowed in some areas, as the connection to the GEC must be accessible, when the meter is sealed its not considered

Huh. I've never even heard of this. By that logic, the drop is NOT "accessible" either... and that's still before the splice point.
SOP here. Drive two at the meter and 1/2 done. But understood as, again, one option of many.

If the water line does not qualify as an GE, then it still must be bonded if the interior is a metallic water piping system

Yes, doing the standard jumper at the water heater.. cold-hot-gas trifecta.

I have to ask though, there seems to be a common element which is... "if the waterline DOES / DOES NOT qualify as a GE. Are you referring to the NEC listed qualifiers? And again, where does it say that if it qualifies it MUST be used??

A simpler way to state your SOP is drive two and go home.

Always been SOP for me to do both. Ingrained as a bare minimum.
But good to know that technically, two at the meter is NEC compliant.

 

[James L]

It's best to look at the requirements for the municipality and POCO combined.

 

[Jerramundi]

The only disagreement I have is with your use of the phrase "at the meter". The gec may connect anywhere from the service point up to and including the first disconnecting means. Sometimes the meter is a convenient place to make a g e c connection, sometimes it is not. Some POCOs do not allow a g e c connection there.

I understand. And it's good to point out that "at the meter" is (1) overly simplistic verbiage, but for a reason.. (2) that it's not a required location, but one option out of many.. and (3) that it may not be the easiest/approved of method.

That's why it's good to get some outside perspective.

 

[ActionDave]

And again, where does it say that if it qualifies it MUST be used??

250.50

 

[electrofelon]

I always like to point out that bonding the water piping and using an underground water pipe as a grounding electrode are two different things, although you probably can kill two birds with one stone.

 

[Jerramundi]

You are required to connect to all available electrodes. If cold water pipingis available and qualifies , you are to use it as an electrode no matter how impractical it is to connect to it

If you're referring to 250.50 "All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building... shall be bonded together...

I would argue that "bonding" them is NOT the same as "using it as an electrode." I see your point that if it qualifies as an electrode, per 250.50 it needs to be BONDED to the GEC system.... but bonding it can be done at the water heater... turning it into an electrode is different. 250.53(D)(1) kicks in requiring the continuous line jumping the meter at the main.

 

[Jerramundi]

(1) Bonding all GEs together.. is NOT the same thing as.. (2) requiring you to use the water pipe as a GE. At least that's my understanding of it.

 

[Jerramundi]

What exactly is no "grounding at the meter,"?

Don't ask me. Just quoting the inspection. Although to be fair, I'd probably say something similar in trying to get the point across. He's just referencing what is SOP around here. Driving two rods at the electrical meter.

I typically use the term "meter" for the "Electrical Service kW/hr Measurement Device" and "main" for the water main.
But I understand that's a bit sloppy.

 

[infinity]

If you're referring to 250.50 "All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building... shall be bonded together...

I would argue that "bonding" them is NOT the same as "using it as an electrode." I see your point that if it qualifies as an electrode, per 250.50 it needs to be BONDED to the GEC system.... but bonding it can be done at the water heater... turning it into an electrode is different. 250.53(D)(1) kicks in requiring the continuous line jumping the meter at the main.

The requirement for connection when using the water pipe as an electrode is in 250.68(C)(1).

250.68
(C) Grounding Electrode Conductor 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 that is electrically continuous with a metal underground water pipe electrode and is located not more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted to extend the connection to an electrode(s). Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a conductor to interconnect electrodes of the grounding electrode system.

 

[Jerramundi]

The requirement for connection when using the water pipe as an electrode is in 250.68(C)(1).

Key words: "when using the water pipe as an electrode."
253.53(D) Metal Underground Water Pipe starts the same way... "If used as a grounding electrode."

If used as a grounding electrode, I have to run a GEC to the street side of the water main.
If "bonding the metal water pipe to the GECs" I can install a jumper to a local conduit (i.e. at the water heater) per 250.104(A)

The requirement to have a GEC go all the way to the street side of the water main is only when used as an electrode.

250.104(A)(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded to any of the following:
(1) Service equipment enclosure
(2) Grounded conductor at the service
(3) Grounding electrode conductor, if of sufficient size
(4) One or more grounding electrodes used, if the grounding electrode conductor or bonding jumper to the grounding electrode is of sufficient size

The bonding jumper(s) shall be installed in accordance with 250.64(A), 250.64(B), and 250.64(E). The points of attachment of the bonding jumper(s) shall be accessible. The bonding jumper(s) shall be sized in accordance with Table 250.102(C)(1) except that it shall not be required to be larger than 3/0 copper or 250 kcmil aluminum or copper-clad aluminum and except as permitted in 250.104(A)(2) and 250.104(A)⁠(3).

 

[ActionDave]

(1) Bonding all GEs together.. is NOT the same thing as.. (2) requiring you to use the water pipe as a GE. At least that's my understanding of it.

Well if it makes you feel any better to call the water pipe part of the grounding electrode system instead of calling it a grounding electrode then do that. Either way it needs to be bonded within five feet of where it enters the building, not at the water heater.

 

[tom baker]

Re: connection of the GEC in the meter: In Washington, we are not permitted to connect in the meter as its not accessible once the POCO installs the seal. Different areas have different rules from the POCO for what can and can't be done. As far as connecting the GEC to the service drop, its not commonly done, but allowed by the NEC, and since the GEC and GE system is for lightning protection, this is a good place for the connection, as it allows a direct connection to ground instead of inside in the panel.

 

[don_resqcapt19]

If you're referring to 250.50 "All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building... shall be bonded together...

I would argue that "bonding" them is NOT the same as "using it as an electrode." I see your point that if it qualifies as an electrode, per 250.50 it needs to be BONDED to the GEC system.... but bonding it can be done at the water heater... turning it into an electrode is different. 250.53(D)(1) kicks in requiring the continuous line jumping the meter at the main.

It says all that are present must be bonded together to form a grounding electrode system. The language is clear that all of the electrodes that are present must be used and connected together to form the grounding electrode system for the building or structure.

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. 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. 9/quote]

 

[infinity]

Key words: "when using the water pipe as an electrode."
253.53(D) Metal Underground Water Pipe starts the same way... "If used as a grounding electrode."

If used as a grounding electrode, I have to run a GEC to the street side of the water main.
If "bonding the metal water pipe to the GECs" I can install a jumper to a local conduit (i.e. at the water heater) per 250.104(A)

The requirement to have a GEC go all the way to the street side of the water main is only when used as an electrode.

Where are the words "street side of the water main" in the NEC? The requirement is within 5', the water main is not invloved.

 

[ActionDave]

Key words: "when using the water pipe as an electrode."
253.53(D) Metal Underground Water Pipe starts the same way... "If used as a grounding electrode."

I think you are misreading the word "if" to mean you have a choice whether or not to use a qualifying underground water pipe as a grounding electrode. You don't.