Results 1 to 30 of 30
  1. #1
    Join Date
    Mar 2007
    Location
    Cape Cod, Massachusetts
    Posts
    614

    Default Grounding electrode - DWV piping

    Is it OK to use the copper DWV piping as a grounding electrode.? It connects to cast iron soil pipe that exits the foundation. I suspect the joint for copper to cast iron is oakum (sp?) and lead.

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Inspection Referral
    Ken Amelin
    Cape Cod's Best Inspection Services
    www.midcapehomeinspection.com

  2. #2
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Ken Amelin View Post
    Is it OK to use the copper DWV piping as a grounding electrode.? It connects to cast iron soil pipe that exits the foundation. I suspect the joint for copper to cast iron is oakum (sp?) and lead.
    I suspect not for many reasons.

    What are the GEC requirements?
    The GEC material must be located with 5' feet from the point of entrance can be used to INTERCONNECT electrodes that are part of the GE system. (Approved earth connection).

    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  3. #3
    Join Date
    Aug 2008
    Location
    Maryland
    Posts
    1,970

    Default Re: Grounding electrode - DWV piping

    The NEC allows the connection on the incoming water line, not the exiting water.

    All answers based on unamended National Electrical codes.

  4. #4
    Join Date
    Mar 2007
    Location
    Cape Cod, Massachusetts
    Posts
    614

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jim Port View Post
    The NEC allows the connection on the incoming water line, not the exiting water.
    I've asked this question because the code does allow other metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal water pipe. (250.52 (A)(8). Just not sure if the copper DWV with the connection to cast iron pipe is allowed.

    Ken Amelin
    Cape Cod's Best Inspection Services
    www.midcapehomeinspection.com

  5. #5
    Join Date
    Mar 2007
    Location
    Santa Rosa, CA
    Posts
    3,154

    Default Re: Grounding electrode - DWV piping

    Ken,

    Pipe electrodes are allowed by the NEC and code is not specific as to what the actual function of the pipe is (2011 NEC - 250.52). However, in my area, metal sewer drain piping faded away in the late 1960s. In those homes, once the cast iron sewer drain pipe exited the building, it typically changed to clay or transite. As it fails, older clay & transite sewer drain piping is being replaced with plastic (in my area) as is much of the older metal supply piping. In either case, the metal pipe is required to be in contact with soil for 10 feet and it's difficult to know if it is or not.

    Also, if the grounding electrode is a pipe, plate or rod electrode, it is currently required to have a supplemental electrode. The details of this have changed over the past several code cycles.

    in conclusion, in the case that you described, I would be concerned that the system is not properly grounded and would defer to an electrical contractor.

    Department of Redundancy Department
    Supreme Emperor of Hyperbole
    http://www.FullCircleInspect.com/

  6. #6
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Ken Amelin View Post
    I've asked this question because the code does allow other metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal water pipe. (250.52 (A)(8). Just not sure if the copper DWV with the connection to cast iron pipe is allowed.
    Ken,

    You mentioned 250.52(A)(8) ... you first must start with 250.50 Grounding Electrode System.

    In there you will see that the electrodes listed in 250.52(A)(1) through (A)(7) are referenced as the grounding electrodes and shall all be bonded together. 250.50 then goes on to say that if none of the other grounding electrodes are present, you can use 250.52(A)(4) through (A)(8) ... that is the first place (A)(8) is mentioned.

    Quote Originally Posted by Gunnar Alquist View Post
    ... in the case that you described, I would be concerned that the system is not properly grounded and would defer to an electrical contractor.
    I would chose wording other than "defer to" as "deferring to" someone else does not give you the opportunity to then say 'they may have said that, but it is still wrong because ... '

    In the case of Ken's photo, I would address it something to the affect of: no proper and preferred grounding electrode connection was found; a connection was found to the underground building sewer pipe which was cast iron, cast iron joints may not provide a suitable electrical connection from cast iron pipe section to cast iron pipe section and thus may not serve as a suitable grounding electrode - recommend a qualified and licensed electrical contractor verify that a proper and suitable grounding electrode system is present with a proper connection to it' (wording varies as will your mileage).

    You have now explained what and why, and if the contractor comes back and says that is okay (unlikely) ... you can still have your reservations on it - if the contractor comes back and says they installed two ground rods ... the contractor addressed the issue (whether or not the contractor addressed the issue by installing two ground rods in the proper and correct manner is not something you are involved in, that is the electrical contractor who is responsible for that.

    I just never "deferred" anything to anyone - I did "recommend" a lot of things to a lot of people.

    Maybe that's being nit-picky about wording, if it is, so be it.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  7. #7
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    Ken,

    You mentioned 250.52(A)(8) ... you first must start with 250.50 Grounding Electrode System.

    In there you will see that the electrodes listed in 250.52(A)(1) through (A)(7) are referenced as the grounding electrodes and shall all be bonded together. 250.50 then goes on to say that if none of the other grounding electrodes are present, you can use 250.52(A)(4) through (A)(8) ... that is the first place (A)(8) is mentioned... .Maybe that's being nit-picky about wording, if it is, so be it.
    Jerry, may I offer you a nit:

    250.50 does NOT say that if the first four types of electrode are not available you can use those mentioned in 250.52(A)(4) through (A)(8). It may well be that they meant that, but what they said is nastily different. They say that if the first four types of electrode are not available you can *install* those mentioned in 250.52(A)(4) through (A)(8). Now obviously you install a galvanized 3/4 inch pipe electrode to serve as an electrode. However, I misdoubt that you install an underground structure to serve as an electrode. Shoot, go Ufer.

    Meanwhile, what should your colleagues do as HIs? What do I do as an electrician who's used to HIs referring clients to him? Common sense says that the CMP meant what you said, and if you quote the Code wording, the customer has all the info. The alternative I see, call it cya or call it fiduciary responsibility from a non-attorney, is to say this is not standard, and is legally questionable as to continuity unless someone tests it--a test that is not commonly worth performing, compared to simply adding a new, non-deteriorated, solidly-connected, ground rod or two.

    I grabbed the 1937 NEC and found that (Section 2571) "A continuous underground metal water piping system shall always be used as the grounding electrode where such system is available."
    However, Section 2572 said that where it is not, "Any one or combination of the following may be used: . . .(c) A local metallic underground piping system, well casing, and the like."
    Skip to the 1959, and besides driven pipe, the alternatives in what was now 250.82 (c) becomes "Other local metallic underground systems, such as piping, tanks, and the like."
    Even back then, this section was followed by 250.83 allowing the use of made electrodes IFF none of these were available.
    My point is that in the past, the wording was clear in saying that underground structures were not created to serve as electrodes. So the nit I picked is really an argument about sloppy wording and not about what's legal.


  8. #8
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    Jerry, may I offer you a nit:

    250.50 does NOT say that if the first four types of electrode are not available you can use those mentioned in 250.52(A)(4) through (A)(8). It may well be that they meant that, but what they said is nastily different. They say that if the first four types of electrode are not available you can *install* those mentioned in 250.52(A)(4) through (A)(8). Now obviously you install a galvanized 3/4 inch pipe electrode to serve as an electrode. However, I misdoubt that you install an underground structure to serve as an electrode. Shoot, go Ufer.
    David,

    Actually, the picking at that nit shows the actual wording to be:
    250.50 Grounding Electrode System. 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 those grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.

    250.50 does not state "when" the other electrodes "shall be installed", but if one of those other electrodes turns out to be installed (at whatever point in time), 250.50 does state that the "shall be ... and used".

    Thus the nit's nit is "when" "shall" it be installed? If it is present, the presumption has to be that it was "installed" as all are man-made items and not found to be naturally occurring in nature.

    I agree, the wording, like almost every section in every code, could be written to be more specific, however, trying to write a code to be specific and clear for 'every conceivable event, and allow for events not even thought of because 'common sense' indicates that 'no one would do such a thing' ... would result in a code which would need to be carried in the trailer of a tractor-trailer rig ... just not practical.

    So I forgive such simple 'non-specific' wording in stating what it is stating (or at least stating what *I* think it is stating ... therein lies the difference in the use of 'non-specific' wording - everyone reads it slightly differently.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  9. #9
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    So I forgive such simple 'non-specific' wording in stating what it is stating (or at least stating what *I* think it is stating ... therein lies the difference in the use of 'non-specific' wording - everyone reads it slightly differently.
    I'm with you, Jerry, including your emoticon, but as a logodaedalian I prefer that rulebooks contain language that says what its author thinks s/he's saying. And a minimum of special language, by which I mean language used with different meanings than the novice would expect, i.e. terms of art (and other non-ordinary cultural institutions).

    So thanks to this query I have offered the IAEI solons a proposal for the 2020 NEC. I hope to correct the change made in the 2002 version that mixes underground structures with made electrodes under "install and use," whereas through the 1999 edition these were part of a grouping of "made and other."

    Also, thanks to the recent encouragement of a senior instructor/inspector/CMP sort, I will be re-offering a proposal regarding the NEC's specialized use of the term, "physical damage" by suggesting we define it in Article 100.

    Why all this fuss and nonsense? Partly out of sheer prejudice as a word-lover. Partly, though, because there are a whole lot of people who haven't come up through the electrical industry but need to apply the NEC without benefit of "Of course you and I know what we mean." Some are HIs, some are multihat inspectors, some are PEs, some are inspectors' bosses. Meanwhile, some are apprentices--or DIYs.


  10. #10
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    Would not the position on the DWV exclude it from being a proper ground installation?

    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  11. #11
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by ROBERT YOUNG View Post
    Would not the position on the DWV exclude it from being a proper ground installation?
    I can make an argument for copper drain pipe that leads to the underground pipe functioning as a GEC, but there I'm on shaky grounds, because the NEC specifies them precisely, so unless the copper is 1/4 inch thick that could sink the idea, unless the copper is considered part of the cast-iron system. (Did I just say "grounds"?) I suspect you'd have to run a legally-sized GEC to the pipe near where it emerges from the ground. And I'm pretty sure that's been in the NEC at least 45-50 years.


  12. #12
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    I can make an argument for copper drain pipe that leads to the underground pipe functioning as a GEC, but there I'm on shaky grounds, because the NEC specifies them precisely, so unless the copper is 1/4 inch thick that could sink the idea, unless the copper is considered part of the cast-iron system. (Did I just say "grounds"?) I suspect you'd have to run a legally-sized GEC to the pipe near where it emerges from the ground. And I'm pretty sure that's been in the NEC at least 45-50 years.
    Is the cast iron drain pipe even a qualified grounding electrode? Where is the designed in electrical contact from cast iron pipe section to cast iron pipe section at spigot and hub? There is none? Maybe electrically conductive through the joints, maybe not.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  13. #13
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    Is the cast iron drain pipe even a qualified grounding electrode? Where is the designed in electrical contact from cast iron pipe section to cast iron pipe section at spigot and hub? There is none? Maybe electrically conductive through the joints, maybe not.
    While I agree that it always is best to test or to replace with something certain, I do have some basis (or bs?) for trusting that continuity. Back when I installed hub-type oakum-and-lead cast iron drain/waste pipe, I pounded that lead into firm contact not only with the oakum stop but with the two pipes.

    Now some of the best splices I've seen over the years consisted of long twists that were dipped in solder when the boy with the solder pot came around (and then wrapped with rubber tape and finally friction tape).

    True, those splices were copper-to-copper, but although cast iron has poorer conductivity, I don't know that lead splicing, even without twist-and-dip, would obviate its service as an Item 8 underground structure. Rubber is quite a different matter: if the copper-to-lead connection were made with rubber, I hope it would have been mentioned.


  14. #14
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    David, Jerry, I think the argument/discussion lay within that the code for the GEC, or grounding electrode conductor, is to be within a certain distance from earth, and be defined an "acceptable material size/gauge."
    250.64 Grounding Electrode Conductor Installation.
    Table:
    Ungrounded Conductoror.....................Copper Grounding
    Area of Parallel Conductors
    .................ElectrodeConductor
    12 through 2AWG.............................................8 AWG
    1 or 1/0AWG.............................................. ........6 AWG
    2/0 or 3/0AWG.............................................. .....4 AWG
    Over 3/0 through 350kcmil.............................2 AWG
    Over 350 through 600kcmil.........................1/0 AWG
    Over 600 through 1,100kcmil......................2/0 AWG
    Over 1,100kcmil........................................ .....3/0 AWG

    (B) Grounding Electrode Conductor Protection. Where exposed, as in the case it is, grounding electrode conductors sized (8 AWG) and smaller must be installed in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.

    Would you consider the copper DWV smaller that 8 Guage? I do.

    Just to be more obscure; (Ferrous metal raceways), if one accepts the cast iron waste vent a raceway, containing the grounding electrode conductors "must be made electrically continuous by bonding each end of the ferrous metal raceway to the grounding electrode conductor" [250.64(E)].

    We are still without a GEC.
    GEC; The grounding electrode must be "connected to earth" and to the electrical equipment in such a manner that establishes a zero difference of potential between earth and the electrical equipment. These zero differences of potential will help stabilize voltage for the electrical system. The grounding electrode conductor connects the grounding electrode to the electrical system.
    Section 250.64 in the 2002 NEC: The grounding electrode must be installed in one continuous length without a splice or a joint, unless spliced by an irreversible compression-type connector listed for the purpose or by an exothermic welding process.
    This eliminates cast iron hub and spigot and copper DWV.

    I think what is being over looked is what requirements determine a (Grounding electrode.)
    Grounding electrode. The grounding electrode must be as near as practicable, and preferably in the same area where the system bonding jumper is installed and be one of the following:

    1) Metal water pipe electrode, within 5 ft of the entry to the building [250.52(A)(1)].
    The OP post is clearly out of the (60") inch or (5') five foot rule.

    2) Metal building frame electrode [250.52(A)(2)].


    Also, lets keep in mind; Per Art. 100, a separately derived system is a wiring system whose power is derived from a source where there’s no direct electrical connection to the supply conductors of another system.










    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  15. #15
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by ROBERT YOUNG View Post

    (B) Grounding Electrode Conductor Protection.
    Just to be more obscure; (Ferrous metal raceways), if one accepts the cast iron waste vent a raceway, containing the grounding electrode conductors "must be made electrically continuous by bonding each end of the ferrous metal raceway to the grounding electrode conductor" [250.64(E)].
    Robert, I'm quite lost.

    I've no idea what diameter or gauge copper your intermediate DWV pipe is;
    If it's a copper busbar, I believe it needs to be >= 1/4 inch;
    I've never heard of a raceway containing itself, so I can't see the GEC-protection raceway rule applying; and
    this is the first time I noticed you talking about this being a separately-derived system. Or was that a metaphor?


  16. #16
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    Robert, I'm quite lost.

    I've no idea what diameter or gauge copper your intermediate DWV pipe is;
    If it's a copper busbar, I believe it needs to be >= 1/4 inch;
    I've never heard of a raceway containing itself, so I can't see the GEC-protection raceway rule applying; and
    this is the first time I noticed you talking about this being a separately-derived system. Or was that a metaphor?
    Sorry for my eccentricity, David.
    It is a satirical look at DWV used as a GEC.
    I enjoyed the comparison of raceway containing itself.
    Yes, I used a metaphor.
    The point to the discussion, Grounding electrode - DWV piping, is moot IMO, but then again I could be wrong.

    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  17. #17
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by ROBERT YOUNG View Post
    I enjoyed the comparison of raceway containing itself.
    If it was a raceway containing itself, then it would need to meet the requirements for raceways, would it not?


    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  18. #18
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    If it was a raceway containing itself, then it would need to meet the requirements for raceways, would it not?
    Wheels within wheels, Tovarich.

    I can imagine this, but not for a GEC. I might use it to avoid a transition to a different type of raceway whilst passing through an environment that the first one is not designed for. An example might be IMC contained within NMRC passing through a chemical-storage room at a pool. But then why not RNMC all the way?


  19. #19
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    Wheels within wheels, Tovarich.

    I can imagine this, but not for a GEC. I might use it to avoid a transition to a different type of raceway whilst passing through an environment that the first one is not designed for. An example might be IMC contained within NMRC passing through a chemical-storage room at a pool. But then why not RNMC all the way?
    I don't have my code handy, but with the inside of a raceway in a wet location being deemed to also be a wet location - wouldn't the inside of the RNMC be the same environment as is outside the RNMC?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  20. #20
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    If it was a raceway containing itself, then it would need to meet the requirements for raceways, would it not?
    I concur.

    That brings me back to the OP's post, "Is it OK to use the copper DWV piping as a grounding electrode?" and my reply on post #2, "I suspect not for many reasons.What are the GEC requirements?"
    Article 250 provides the prescriptive methods or, in other words, the actual methods required for grounding and bonding the electrical system.

    Section 250.64 in the 2002 NEC: The grounding electrode must be installed in one continuous length without a splice or a joint, unless spliced by an irreversible compression-type connector listed for the purpose or by an exothermic welding process.

    Moot point about the DWV doubling up as a grounding electrode but I will await others to chime in.


    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  21. #21
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by ROBERT YOUNG View Post
    Section 250.64 in the 2002 NEC: The grounding electrode must be installed in one continuous length without a splice or a joint, unless spliced by an irreversible compression-type connector listed for the purpose or by an exothermic welding process.
    Actually, that is referring to the GEC, not the grounding electrode.

    This is what it says about "water pipe":
    250.52(A)(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.

    That was why I mentioned the spigot/hub joints of cast iron pipe ... does that count as being "electrically continuous" even with caulked oakum/lead joints? What 'assures' that the joints are "electrically continuous"? We have all seen leaking cast iron joints, that alone cautions against the lead making an "electrically continuous" connection from cast iron section to cast iron section.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  22. #22
    Join Date
    Oct 2010
    Location
    MONTREAL QUEBEC-CANADA
    Posts
    2,075

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    Actually, that is referring to the GEC, not the grounding electrode.

    This is what it says about "water pipe":
    250.52(A)(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.

    That was why I mentioned the spigot/hub joints of cast iron pipe ... does that count as being "electrically continuous" even with caulked oakum/lead joints? What 'assures' that the joints are "electrically continuous"? We have all seen leaking cast iron joints, that alone cautions against the lead making an "electrically continuous" connection from cast iron section to cast iron section.
    Jerry, much thanks for the correction.
    I should have avoided posting. I have a terrible virus and my sinuses are inflamed.
    I should know better.

    Robert Young's Montreal Home Inspection Services Inc.
    Call (514) 489-1887 or (514) 441-3732
    Our Motto; Putting information where you need it most, "In your hands.”

  23. #23
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post

    That was why I mentioned the spigot/hub joints of cast iron pipe ... does that count as being "electrically continuous" even with caulked oakum/lead joints? What 'assures' that the joints are "electrically continuous"? We have all seen leaking cast iron joints, that alone cautions against the lead making an "electrically continuous" connection from cast iron section to cast iron section.
    Jerry, I don't believe that DWV pipe is in the same category as "water pipe," but think that it falls into the imperfectly defined category you noted, (8) other metal underground structures that are not bonded to water . There is no Code requirement that these be proven electrically continuous (an undefined or at least nonmetricated term). Surely leaking versus containing water or other contents has a very variable relation to electrical continuity, defined as conductance or impedance.


  24. #24
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    Jerry, I don't believe that DWV pipe is in the same category as "water pipe," but think that it falls into the imperfectly defined category you noted, (8) other metal underground structures that are not bonded to water .
    While I am in agreement on that point, the NEC does specify what "water pipe" is.

    The NEC does not even require that the "water pipe" be filled with water, or even contain water, only that the pipe be "water pipe" in purpose and intent.

    While speaking of "intent", I think that "intent" of the code is that it is intending to refer to "water service" pipe.

    Doesn't say that, but I believe that is the code's intent ... and the common application of the code ... which means that this entire discussion has been an exercise in futility.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  25. #25
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    I don't have my code handy, but with the inside of a raceway in a wet location being deemed to also be a wet location - wouldn't the inside of the RNMC be the same environment as is outside the RNMC?
    Good point.

    This is a sticky one. We do recognize some barriers to protect raceways, and others to protect their contents. For instance, EMT can be used in some locations so long as it is protected by paint or suitable wrapping, but conductors inside it have to be rated for wet locations.
    We also recognize some raceways as providing barriers against hazardous environments, more or less . . . but still require sealing compound around the conductors they contain as they exit the environments containing the combustible gases or dusts.

    I would be inclined to accept a continuous length of RNMC from wall to wall as providing a barrier against metal-corrosive but plastic-inert atmospheres, or at least investigate the possibility.


  26. #26
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    I forgot to include this part:

    Quote Originally Posted by david shapiro View Post
    There is no Code requirement that these be proven electrically continuous (an undefined or at least nonmetricated term).
    Correct.

    However, (referring back to the "code") there is a code requirement that water pipe be "electrically continuous" ... and I am sure that you know what happens when something is questioned as meeting the code - the AHJ has the power to say (in nicer words): prove it.

    And it is up to the contractor to "prove it" and at the contractor's expense for the tests necessary to "prove it".

    If the contractor cannot satisfy the AHJ, the code does give the remedy - bonding across the joists ... it is in the code.

    Just sayin'.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  27. #27
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    I forgot to include this part:



    Correct.

    However, (referring back to the "code") there is a code requirement that water pipe be "electrically continuous" ... and I am sure that you know what happens when something is questioned as meeting the code - the AHJ has the power to say (in nicer words): prove it.

    And it is up to the contractor to "prove it" and at the contractor's expense for the tests necessary to "prove it".

    If the contractor cannot satisfy the AHJ, the code does give the remedy - bonding across the joists ... it is in the code.

    Just sayin'.
    Are you saying that while originally you considered DWV pipe potentially acceptable as an electrode under 250.52(A)(8), Other Local Metal Underground Systems or Structures . . .such as piping systems not bonded to a metal water pipe, you now are treating them as though they were metal water pipes? Some inspectors make up code, but those I respect will cite language supporting their challenges, and there's no "continuous" or "jumper" in the language of 2011's Section 250.50 or 250.52(A)(8), just in 250.52(A)(1). I'm not saying it shouldn't be there, but it isn't now and the value of adding it probably wouldn't warrant a t.i.a.


  28. #28
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    Are you saying that while originally you considered DWV pipe potentially acceptable as an electrode under 250.52(A)(8), Other Local Metal Underground Systems or Structures . . .such as piping systems not bonded to a metal water pipe, you now are treating them as though they were metal water pipes?
    I'm not saying that I originally considered the DWV/building sewer pipe potentially acceptable, I went through the discussion with everyone's posts following them and addressing the applicable code as best possible, and showing how the code applied, or did not apply, as the case may be to the discussion as it went on.

    Could the building sewer be used as a grounding electrode? That would be up to the AHJ based on the code posted and our discussions.

    Is it prohibited from serving as a grounding electrode by the code? The code does not address it as being prohibited.

    Does it meet the requirements of an underground water pipe? I think I pointed out the things which would need to be done even if the AHJ went along with it.

    Quote Originally Posted by david shapiro View Post
    Some inspectors make up code, but those I respect will cite language supporting their challenges, and there's no "continuous" or "jumper" in the language of 2011's Section 250.50 or 250.52(A)(8), just in 250.52(A)(1). I'm not saying it shouldn't be there, but it isn't now and the value of adding it probably wouldn't warrant a t.i.a.
    Did you read the code section I posted? I typed it right out of the 2014 NEC, and it says: (underlining is mine for the reference to this below it)
    Quote Originally Posted by Jerry Peck
    This is what it says about "water pipe":
    250.52(A)(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.


    Quote Originally Posted by david shapiro View Post
    Some inspectors make up code, ...
    And some argue the code without going back and verifying what it says - did you even read the 2011 NEC or are you just stating it from memory?

    The only difference between the 2014 and the 2011 is that the 2014 has the underlined part above added to what was in the 2011 - so the 2011 does state that the water pipe be "
    electrically continuous". And the 2011 does not indicate that it is different than the 2005 ... I even went back to the 1993 NEC and "electrically continuous" is in there - and no indication shown that it was new to the 1993, which means I could have gone back even further ... but the point is that you apparently need to re-read the NEC code sections I posted ... IT IS in there (albeit in 1993 the section numbers were different).

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  29. #29
    Join Date
    Oct 2014
    Location
    Maryland, DC, and Northern Virginia, electrical only
    Posts
    444

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by Jerry Peck View Post
    I'm not saying that I originally considered the DWV/building sewer pipe potentially acceptable, I went through the discussion with everyone's posts following them and addressing the applicable code as best possible, and showing how the code applied, or did not apply, as the case may be to the discussion as it went on.

    Could the building sewer be used as a grounding electrode? That would be up to the AHJ based on the code posted and our discussions.

    Is it prohibited from serving as a grounding electrode by the code? The code does not address it as being prohibited.

    Does it meet the requirements of an underground water pipe? I think I pointed out the things which would need to be done even if the AHJ went along with it.



    Did you read the code section I posted? I typed it right out of the 2014 NEC, and it says: (underlining is mine for the reference to this below it)


    [/COLOR]

    And some argue the code without going back and verifying what it says - did you even read the 2011 NEC or are you just stating it from memory?

    The only difference between the 2014 and the 2011 is that the 2014 has the underlined part above added to what was in the 2011 - so the 2011 does state that the water pipe be "
    electrically continuous". And the 2011 does not indicate that it is different than the 2005 ... I even went back to the 1993 NEC and "electrically continuous" is in there - and no indication shown that it was new to the 1993, which means I could have gone back even further ... but the point is that you apparently need to re-read the NEC code sections I posted ... IT IS in there (albeit in 1993 the section numbers were different).
    It seems that our difference is based on whether a water-type pipe is treated by the NEC as a "water pipe" however it is employed. I say no: sometimes it's a bollard, sometimes it's a protective sleeve, sometimes it's a drain pipe, and in all these cases the code that is specific to water pipe is not referring to it. And yes sir, I did read these code sections, multiple times, to minimize the chance I was missing anything.
    I'm done with this discussion.
    Politesse, toujours
    Our differen


  30. #30
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Grounding electrode - DWV piping

    Quote Originally Posted by david shapiro View Post
    I'm done with this discussion.
    Without even acknowledging that the code section does indeed as "electrical continuity" or again trying to state otherwise ... slipping out without addressing that.

    Water pipe is sometimes a bollard?

    Really?

    It's not "water pipe" if it does not, or is not intended to, carry water.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •