AHJ Grounding Electrode Requirement

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don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I don?t know what you mean electrically connected.
You said that if you used a meter to read the resistance between the cold and hot water piping and the meter said you had an open circuit, that there would be no requirement for any 250.104(A) bond.
The code panel was very clear that if the system is not a complete metal system then drop down to (B).
I don't read the CMP's comments that way. I read them as saying you still have a system that is covered by 250.104(A), and you have other water piping that is covered by 250.104(B).

Something about the laws of physics says that if the system is a complete metal system then there would be continuity from any point on the system to any other point on the system. Should there not be continuity from any point on the system to any other point on the system there must be something nonmetallic in there somewhere and this would then be an integrated system. ...
You just told me your previous post that if we don't have continuity between the hot and cold piping that we don't have a water piping system. Now you say we have an "integrated" system. I have no idea what that means.
 

kwired

Electron manager
Location
NE Nebraska

I have been trying to stay out of the debate of the "water systems". I do understand what that label says, and have understood that concept before ever reading that. That said you can have all the isolation you want at the water heater, but if the entire hot and cold piping (dare I add "systems") are metallic and there is also metallic mixing devices, like maybe a shower valve they are bonded together anyway via points like that. Just my $.02 worth, some still don't think that is sufficient enough to ensure that there is a bond around a dielectric union:angel:.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
I have been trying to stay out of the debate of the "water systems". I do understand what that label says, and have understood that concept before ever reading that. That said you can have all the isolation you want at the water heater, but if the entire hot and cold piping (dare I add "systems") are metallic and there is also metallic mixing devices, like maybe a shower valve they are bonded together anyway via points like that. Just my $.02 worth, some still don't think that is sufficient enough to ensure that there is a bond around a dielectric union:angel:.

Glad you're getting your feet 'wet'. Think of a shower as an 'outlet' and the piping as 'wiring'.

I agree that a shower may conduct electricity but is is approved as a bonding device? Can I use drywall screws for bonding they are metal?
 

jwelectric

Senior Member
Location
North Carolina
You said that if you used a meter to read the resistance between the cold and hot water piping and the meter said you had an open circuit, that there would be no requirement for any 250.104(A) bond.
I don't read the CMP's comments that way. I read them as saying you still have a system that is covered by 250.104(A), and you have other water piping that is covered by 250.104(B).
No what they say in their statement is a complete metal water system.


You just told me your previous post that if we don't have continuity between the hot and cold piping that we don't have a water piping system. Now you say we have an "integrated" system. I have no idea what that means.
You are really close on that quote but you left out a word that fits in there somewhere;
if we don't have continuity between the hot and cold piping that we don't have a water piping system.
When this is what I said;
if we don't have continuity between the hot and cold piping that we don't have a metal water piping system.

Instead of a metal water piping system we have an intergated system or a system with more than one piping method used.

When this debate came up some time back the question kept being asked at what length would it be called a system.

On a side note; Just how would all this foolish bonding be done should I make a plumbing code compliant installation of small insta-hot heaters located at each fixture. It would be possible to have a bunch of these different systems being bonded by table 250.66
 

jwelectric

Senior Member
Location
North Carolina
So do we need to decide if this is a system divided or two systems?
Every time I run into an inspector that is on my job trying to sell me on the idea that there are two water systems there I always ask them a couple of simple questions and then the discussion usually ends.

Is the water that enters this water heater potable water?
Is the water that leaves this water heater the same potable water that flowed into this water heater just a little warmer?

I agree that the plumbing code has a little different rules for the hot water lines in some cases but these different rules does not change the water that flows through the pipes, it is all potable water and it is all part of the potable water system.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
Every time I run into an inspector that is on my job trying to sell me on the idea that there are two water systems there I always ask them a couple of simple questions and then the discussion usually ends.

Is the water that enters this water heater potable water?
Is the water that leaves this water heater the same potable water that flowed into this water heater just a little warmer?

I agree that the plumbing code has a little different rules for the hot water lines in some cases but these different rules does not change the water that flows through the pipes, it is all potable water and it is all part of the potable water system.

Let's say that I call it one complete system. Is it possible to bond the first 5' install a water softener then just forget bonding the rest of the water lines? Assuming metal water lines what would you do, if anything, here?

central-water-install-diagr.jpg
http://www.kenmorewater.com/website...ter/central-water-filtration-installation.htm
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
...
You are really close on that quote but you left out a word that fits in there somewhere;
if we don't have continuity between the hot and cold piping that we don't have a water piping system.
When this is what I said;
if we don't have continuity between the hot and cold piping that we don't have a metal water piping system.

Instead of a metal water piping system we have an intergated system or a system with more than one piping method used.

When this debate came up some time back the question kept being asked at what length would it be called a system.

On a side note; Just how would all this foolish bonding be done should I make a plumbing code compliant installation of small insta-hot heaters located at each fixture. It would be possible to have a bunch of these different systems being bonded by table 250.66
Well, that is not the way it is around here. If you have metal water pipe and even if there are sections that are electrically isolated, you will not pass inspection unless you have a 250.66 sized bond to the metal piping. They do not require that small isolated sections be bonded, but they do require bonding between the hot and cold water systems if they are isolated. This interpretation is supported by most, if not all, of the inspector associations in Illinois.

I still don't read the panel comments the way you do so as always we will not agree on this issue.
 
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hurk27

Senior Member
Glad you're getting your feet 'wet'. Think of a shower as an 'outlet' and the piping as 'wiring'.

I agree that a shower may conduct electricity but is is approved as a bonding device? Can I use drywall screws for bonding they are metal?

and you can ask the same question for every fitting in the plumbing system, what about all the T's and Elbows all soldered in place just like most mixing valves so where are you going to go with this???
 

Finite10

Senior Member
Location
Great NW
I asked a guy who bonded to the cold water pipe to walk it back to where the cold water entered the warehouse with me. He said, "But THEY bonded to that pipe". Anyway, the copper waterpipe was changed to plastic for about 40' before connecting to the copper that entered the building.

For me;
If there's 10' of metal pipe (usually copper) in the dirt - it's a good earth ground. If the interior plumbing is done with Pex pipe, there's no point in bonding hot-to-cold at the water heater.

The grounding system that uses more than one element of a GEC system is best, IMHO, and the #6 Cu to 2 ground rods is weak - especially in larger services or poor AIC conditions where the fault can be bad. Building steel is good if it's a type 1 or 2 structure. Type 3, not so much.

The problem with driving ground rods at a tilt-up warehouse is the very wide footings. You'd have the guy driving rods in the parking lot!

Lightning is not much of an issue here, but that's starting to change lately.
 
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jwelectric

Senior Member
Location
North Carolina
Let's say that I call it one complete system. Is it possible to bond the first 5' install a water softener then just forget bonding the rest of the water lines? Assuming metal water lines what would you do, if anything, here?

View attachment 7233
http://www.kenmorewater.com/website...ter/central-water-filtration-installation.htm

The first five feet after entering the building is to be used for a path to the electrode if there is 10 feet of metal pipe in contact with earth a requirement of 250.68(C)

If the rest of the piping is a complete metal system I will install the 250.104(A)(1) bonding conductor to any convenient point on the system somewhere. It could be at the very end of the piping system. If there is isolation of the interior piping system at all of any kind then the bonding will fall under 250.104(B)

I would not in any way try to make one bond to the cold pipe and then do another bond to the hot pipe and absolutely would not make a non- code compliant installation of bonding with a short conductor from the cold pipe to the hot pipe at the water heater unless someone can show me something in writing where the jurisdiction has adopted something different than what is written in the code.

Again how would you bond pipes if water heaters was installed at each fixture?
 

jwelectric

Senior Member
Location
North Carolina
Well, that is not the way it is around here. If you have metal water pipe and even if there are sections that are electrically isolated, you will not pass inspection unless you have a 250.66 sized bond to the metal piping. They do not require that small isolated sections be bonded, but they do require bonding between the hot and cold water systems if they are isolated. This interpretation is supported by most, if not all, of the inspector associations in Illinois.

I still don't read the panel comments the way you do so as always we will not agree on this issue.

If Illinois has not made some sort of amendment then the bonding across the water heater is a violation of 250.104(A)(1) as this section is clear that the bonding conductor MUST be to the service enclosure, the neutral at the service, one of the ECG, or a grounding electrode. The only part of the metal piping system that fits that definition is the first five feet that enters the building and then only if there is 10 feet in contact with earth.
 
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Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
The first five feet after entering the building is to be used for a path to the electrode if there is 10 feet of metal pipe in contact with earth a requirement of 250.68(C)

If the rest of the piping is a complete metal system I will install the 250.104(A)(1) bonding conductor to any convenient point on the system somewhere. It could be at the very end of the piping system. If there is isolation of the interior piping system at all of any kind then the bonding will fall under 250.104(B)

I would not in any way try to make one bond to the cold pipe and then do another bond to the hot pipe and absolutely would not make a non- code compliant installation of bonding with a short conductor from the cold pipe to the hot pipe at the water heater unless someone can show me something in writing where the jurisdiction has adopted something different than what is written in the code.

Again how would you bond pipes if water heaters was installed at each fixture?

For something that bears no confusion for you, you are confusing the heck out of me. The above comment refers to the sketch. By what you have posted previously in this thread, the "rest of the piping" can't be a complete metal system, because the first 5 feet is isolated from the rest of the system. You already stated that this is not a complete system! So, 250.104(A)(1) wouldn't apply. I will repeat again that this code section bites the big one!
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
If Illinois has not made some sort of amendment then the bonding across the water heater is a violation of 250.104(A)(1) as this section is clear that the bonding conductor MUST be to the service enclosure, the neutral at the service, one of the ECG, or a grounding electrode. The only part of the metal piping system that fits that definition is the first five feet that enters the building and then only if there is 10 feet in contact with earth.

Disagree. This is not "THE" bond, it is a bond. I can run a piece of copper to every water faucet in my house if I want to, just because it looks pretty. No violation of code. If the cold water pipe is copper from the water heater back to the point where it is bonded to the grounding electrode system then the hot water and the gas pipe are effectively and code worthy bonded also. Again no code violation.
 

kwired

Electron manager
Location
NE Nebraska
Glad you're getting your feet 'wet'. Think of a shower as an 'outlet' and the piping as 'wiring'.

I agree that a shower may conduct electricity but is is approved as a bonding device? Can I use drywall screws for bonding they are metal?
Hurk nailed my reply before I could:

and you can ask the same question for every fitting in the plumbing system, what about all the T's and Elbows all soldered in place just like most mixing valves so where are you going to go with this???






I asked a guy who bonded to the cold water pipe to walk it back to where the cold water entered the warehouse with me. He said, "But THEY bonded to that pipe". Anyway, the copper waterpipe was changed to plastic for about 40' before connecting to the copper that entered the building.

For me;
If there's 10' of metal pipe (usually copper) in the dirt - it's a good earth ground. If the interior plumbing is done with Pex pipe, there's no point in bonding hot-to-cold at the water heater.

Here is an example of '2 systems' as far as NEC is concerned: The interior piping that must be bonded, and the underground metal water piping that must be used as a grounding electrode regardless of whether or not it remains a metallic system after it enters the building.

The grounding system that uses more than one element of a GEC system is best, IMHO, and the #6 Cu to 2 ground rods is weak - especially in larger services or poor AIC conditions where the fault can be bad. Building steel is good if it's a type 1 or 2 structure. Type 3, not so much.
Grounding electrode system is not intended to carry ground fault current. There are cases where it can but it is not reqired to be able to do so. If earth is only path back to the source it will almost always be too high of a resistance to carry full available ground fault current.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
You said that if you used a meter to read the resistance between the cold and hot water piping and the meter said you had an open circuit, that there would be no requirement for any 250.104(A) bond.
I don't read the CMP's comments that way. I read them as saying you still have a system that is covered by 250.104(A), and you have other water piping that is covered by 250.104(B).


You just told me your previous post that if we don't have continuity between the hot and cold piping that we don't have a water piping system. Now you say we have an "integrated" system. I have no idea what that means.

This is pretty much how I see this also.

Again, I will say that 250.104(A) should just plain go away! What is the point of it? 250.104(B) protects personnel from electrical shock of any metal piping. Rock of Marne, at least, indicates that the isn't isn't to ensure a path back to the service bond, for say a separately derived system, so just GET RID OF THIS SECTION and save the customer some money.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
and you can ask the same question for every fitting in the plumbing system, what about all the T's and Elbows all soldered in place just like most mixing valves so where are you going to go with this???

Fittings ARE part of the piping. Mixing valves are not.

I would not in any way try to make one bond to the cold pipe and then do another bond to the hot pipe and absolutely would not make a non- code compliant installation of bonding with a short conductor from the cold pipe to the hot pipe at the water heater unless someone can show me something in writing where the jurisdiction has adopted something different than what is written in the code.

Again how would you bond pipes if water heaters was installed at each fixture?

Non-compliant?

You would not have to bond at water heaters at each fixture.

If Illinois has not made some sort of amendment then the bonding across the water heater is a violation of 250.104(A)(1) as this section is clear that the bonding conductor MUST be to the service enclosure, the neutral at the service, one of the ECG, or a grounding electrode. The only part of the metal piping system that fits that definition is the first five feet that enters the building and then only if there is 10 feet in contact with earth.

NO. Since it is ONE system we will use.

(4) Bonding of Electrically Conductive Materials and
Other Equipment. Normally non–current-carrying electrically
conductive materials that are likely to become energized
shall be connected together and to the electrical supply
source in a manner that establishes an effective groundfault
current path.
(5) Effective Ground-Fault Current Path. Electrical equipment
and wiring and other electrically conductive material
likely to become energized shall be installed in a manner that
creates a low-impedance circuit facilitating the operation of
the overcurrent device or ground detector for high-impedance
grounded systems. It shall be capable of safely carrying the
maximum ground-fault current likely to be imposed on it from
any point on the wiring system where a ground fault may
occur to the electrical supply source. The earth shall not be
considered as an effective ground-fault current path

DID you forget about this for the 10' and first 5'?

250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
(1) Metal Underground Water Pipe. A metal underground
water pipe in direct contact with the earth for 3.0 m (10 ft) or
more (including any metal well casing bonded to the pipe) and
electrically continuous (or made electrically continuous by
bonding around insulating joints or insulating pipe) to the
points of connection of the grounding electrode conductor and
the bonding conductor(s) or jumper(s), if installed.
 
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kwired

Electron manager
Location
NE Nebraska
Fittings ARE part of the piping. Mixing valves are not.

Are they better, worse, or about same value of conductor for bonding each side of the valve as a couple bonding clamps and a jumper wire? Does it make sense to bond around something that has no significant resistance?
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
Forgot:

250.53 Grounding Electrode System Installation.
(D)
(1) Continuity. Continuity of the grounding path or the
bonding connection to interior piping shall not rely on water
meters or filtering devices and similar equipment.

This is the one that got me thinking years ago.
 
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