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Thread: NC Dept of Insurance Official Interpretations

  1. #11
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    Quote Originally Posted by ptonsparky View Post
    I thought we’re werent supposed to worry about future ‘what ifs’ ? We would never get done.
    The NCDOI can interpret the code and make a formal decision as to how something is interpreted. You are correct that we should use what iof scenarios but that may be just a reason as to why their interpretation makes sense.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  2. #12
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    Quote Originally Posted by Dennis Alwon View Post
    The install is correct but there seems to be a disagreement as to the explanation. Is that how you see it.
    How does a single rod without a resistance of 25 ohms or less qualify as an electrode?
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  3. #13
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    Quote Originally Posted by infinity View Post
    How does a single rod without a resistance of 25 ohms or less qualify as an electrode?
    Where does it say that?

    Question 1:
    If only ground rods are used as an electrode system for a single family dwelling, are two required?

    Answer 1:
    Single electrodes made of rod, pipe, or steel plates must have a resistance to ground of 25 ohms or less, or must be augmented by an additional electrode of a type specified by section 250.52(A)(2) through (A)(7). The installer is required to assure the system meets this requirement and submit proof that is acceptable to the local electrical inspector.
    Note: In extensive testing throughout North Carolina soil conditions have found to be of types prohibiting conductivity meeting the 25 ohms or less requirement for resistance.

    Question 2:
    If a metal underground water pipe is used as part of an electrode system and is supplemented with a ground rod, is another grounding electrode required to supplement the supplemented ground rod?

    Answer 2:
    No. The requirement of section 250.53(D)(2) requires one supplement electrode of a type chosen from sections 250.52(A)(2) through (A)(8), in which a rod is listed in section 250.52(A)(5).
    Both the water pipe and the rod must comply with the installation requirements of section 250.53(A). Because the water pipe and the rod make two electrodes, each supplement the other; thus, 250.53(A)(2) is satisfied.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  4. #14
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    I disagree with their answer for the for the following reasons section 250.53 D(2) requires the supplemental grounding electrode but also states a rod, pipe or plate must comply with 250.53A and there it states a single rod must be supplemented by an additional electrode, excluding water pipe, or meet the 25 ohm requirement.
    250.53 Grounding Electrode System Installation.
    A (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
    Exception: If a single rod, pipe, or plate grounding electrode
    has a resistance to earth of 25 ohms or less, the
    supplemental electrode shall not be required.

    (D) Metal Underground Water Pipe. If used as a grounding
    electrode, metal underground water pipe shall meet the
    requirements of 250.53(D)(1) and (D)(2).
    (2) Supplemental Electrode Required. A metal underground
    water pipe shall be supplemented by an additional
    electrode of a type specified in 250.52(A)(2) through
    (A)(8). If the supplemental electrode is of the rod, pipe, or
    plate type, it shall comply with 250.53(A).
    supplemental electrode shall not be required.
    Rick Napier
    Inspector and Instructor

  5. #15
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    I am not seeing what is wrong. You can have 2 rods or if there is a water pipe (assuming that it is an electrode, of course) you must bond it and then add an additional electrode which is usually a rod.

    Is that not what is being said?
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  6. #16
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    Quote Originally Posted by infinity View Post
    How does a single rod without a resistance of 25 ohms or less qualify as an electrode?


    Quote Originally Posted by Dennis Alwon View Post
    Where does it say that?

    I'm referring to question #2 in your post not question #1. The response to question #2 allows a single rod to supplement the water pipe and the water pipe to supplement the single rod. A single rod is not considered an electrode unless you supplement it or can prove it's 25 ohms or less.

    Rick summed up the code sections nicely.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  7. #17
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    Quote Originally Posted by infinity View Post
    I'm referring to question #2 in your post not question #1. The response to question #2 allows a single rod to supplement the water pipe and the water pipe to supplement the single rod. A single rod is not considered an electrode unless you supplement it or can prove it's 25 ohms or less.
    Yes that was the point I was trying to make.
    Rick Napier
    Inspector and Instructor

  8. #18
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    Around here, when we perform an upgrade, unless there is a way to make certain the water pipe has the required ground contact, we must use two rods.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  9. #19
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    Quote Originally Posted by infinity View Post




    I'm referring to question #2 in your post not question #1. The response to question #2 allows a single rod to supplement the water pipe and the water pipe to supplement the single rod. A single rod is not considered an electrode unless you supplement it or can prove it's 25 ohms or less.

    Rick summed up the code sections nicely.

    So what is it the terminology? If the water pipe and the rod are both bonded then it is compliant. What is the issue other than wording.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  10. #20
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    Quote Originally Posted by Dennis Alwon View Post
    So what is it the terminology? If the water pipe and the rod are both bonded then it is compliant. What is the issue other than wording.
    Here is what I see as the problem in the response to question #2:

    Because the water pipe and the rod make two electrodes, each supplement the other; thus, 250.53(A)(2) is satisfied.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

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