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Thread: Grounding electrode 250.64(D)

  1. #31
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    Quote Originally Posted by jap View Post
    I also have bolted every lug on every transformer that required it my whole career.
    Not once did one come with the logs already installed.

    Jap>
    Hey jap it's more then two threads right

    Sent from my SM-G950U using Tapatalk

  2. #32
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    Quote Originally Posted by jap View Post
    I think saying the bolt and nut not being part of listed equipment is a little too much attention to literature myself.
    In my opinion, the Code language of how a GEC has to be continuous is really curious.

    I get that I'm looking closely at the words of 250.64 . . .

    This is not about the general use and fastening of lugs, but rather what a "continuous" GEC is in this rule.
    Another Al in Minnesota

  3. #33
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    Quote Originally Posted by al hildenbrand View Post
    In my opinion, the Code language of how a GEC has to be continuous is really curious.

    I get that I'm looking closely at the words of 250.64 . . .

    This is not about the general use and fastening of lugs, but rather what a "continuous" GEC is in this rule.
    The GEC(s) end at the busbar. The wires going to each panel are common grounding electrode conductor taps. The transition is not required to be continuous and irreversible when using listed connectors.

    BTW, bolted connections fall under 250.8(A)(5).
    Last edited by Smart $; 09-13-17 at 12:15 AM.
    I will have achieved my life's goal if I die with a smile on my face.

  4. #34
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    Quote Originally Posted by nickelec View Post
    Hey jap it's more then two threads right

    Sent from my SM-G950U using Tapatalk
    I couldn't tell you if it is or not.
    However there was a conversation on that topic a while back also.

    Lets see,,,, I have screw but I'm not sure how many threads per inch it is,,,, and this metal is 14 guage,,,,,not sure if it's going to catch 2 threads or not,,,

    You don't have time in the field to sit and try and figure out if 2 threads will catch, while the rest of your crew knocks out a 100ft run of pipe.

    That's why it's always good to have these conversations while everyone is sitting at a desk behind a computer.

    That way when you take it to the field you simply react and install it with some level of confidence.


    JAP>

  5. #35
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    Agreed and we'll said

    Sent from my SM-G950U using Tapatalk

  6. #36
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    Quote Originally Posted by Smart $ View Post
    The GEC(s) end at the busbar. The wires going to each panel are common grounding electrode conductor taps. The transition is not required to be continuous and irreversible when using listed connectors.

    BTW, bolted connections fall under 250.8(A)(5).
    Yes. This is what is said in the Code, in your words. . . but look at the phrasing of 250.64(D)(1)(3) especially the highlighted green:

    2017 NEC
    250.64 Grounding Electrode Conductor Installation
    250.64(D) Building or Structure with Multiple Disconnecting Means in Separate Enclosures
    250.64(D)(1) Common Grounding Electrode Conductor and Taps

    A grounding electrode conductor tap shall extend to the inside of each disconnecting means enclosure. The grounding electrode conductor taps shall be sized in accordance with 250.66 for the largest service-entrance or feeder conductor serving the individual enclosure. The tap conductors shall be connected to the common grounding electrode conductor by one of the following methods in such a manner that the common grounding electrode conductor remains without a splice or joint:
    (1) Exothermic welding.
    (2) Connectors listed as grounding and bonding equipment.
    (3) Connections to an aluminum or copper busbar not less than 6 mm thick × 50 mm wide (1⁄4 in. thick × 2 in. wide) and of sufficient length to accommodate the number of terminations necessary for the installation. The busbar shall be securely fastened and shall be installed in an accessible location. Connections shall be made by a listed connector or by the exothermic welding process. If aluminum busbars are used, the installation shall comply with 250.64(A).
    As written the busbar does not have to be listed. But the connection to the busbar does have to be listed. In the photo in this thread, the green #6 Grounding Electrode Conductor is connected to the LUG (which is listed). The lug, in turn is connected to the busbar.

    It is the second connection, the connection of the listed lug to the busbar that is, in my opinion, included in 250.64(D)(1)(3) as a "Connections to an . . . busbar . . . "

    Clearly, for an effective low impedance electrical path to be accomplished, the LUG must be connected to the "busbar" (a busbar constructed as physically described in 250.64(D)(1)(3)) and I can't see that the language allows an unlisted mechanical bolt and nut, screw or other fastener grabbed off the truck to do the "connection to an . . . busbar . . ."

    The connection to the busbar must be by a "listed connector."

    If the lug was supplied with a fastener that was part of the listing of the lug, you know, like the screws that come with an EGC terminal strip, or the MBJ screw that is included with a panel suitable as Service Equipment, then I believe the NEC rule is satisfied. But the photo in this thread shows generic listed lugs held with generic unlisted fasteners.
    Last edited by al hildenbrand; 09-13-17 at 11:56 AM.
    Another Al in Minnesota

  7. #37
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    Quote Originally Posted by al hildenbrand View Post
    Yes. This is what is said in the Code, in your words. . . but look at the phrasing of 250.64(D)(1)(3) especially the highlighted green:



    As written the busbar does not have to be listed. But the connection to the busbar does have to be listed. In the photo in this thread, the green #6 Grounding Electrode Conductor is connected to the LUG (which is listed). The lug, in turn is connected to the busbar.

    It is the second connection, the connection of the listed lug to the busbar that is, in my opinion, included in 250.64(D)(1)(3) as a "Connections to an . . . busbar . . . "

    Clearly, for an effective low impedance electrical path to be accomplished, the LUG must be connected to the "busbar" (a busbar constructed as physically described in 250.64(D)(1)(3)) and I can't see that the language allows an unlisted mechanical bolt and nut, screw or other fastener grabbed off the truck to do the "connection to an . . . busbar . . ."

    The connection to the busbar must be by a "listed connector."

    If the lug was supplied with a fastener that was part of the listing of the lug, you know, like the screws that come with an EGC terminal strip, or the MBJ screw that is included with a panel suitable as Service Equipment, then I believe the NEC rule is satisfied. But the photo in this thread shows generic listed lugs held with generic unlisted fasteners.
    I believe you are just being too nit picky. 'Attachment' of a lug with a machine bolt is the conventionally accepted method of electrical connection. The bolt itself is not the sole connection. Mating surfaces actually provide for most of the connection. Additionally, I have already pointed you to 250.8. You've indicated that you accept the lug as being listed for the purpose. I cannot provide you with additional support or argumentative material. You either accept it as convention does or you can continue to object. If the latter, I'll spectate. But that's all.
    I will have achieved my life's goal if I die with a smile on my face.

  8. #38
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    Quote Originally Posted by Smart $ View Post
    I cannot provide you with additional support or argumentative material.
    My words stand on their own.
    Another Al in Minnesota

  9. #39
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    Quote Originally Posted by al hildenbrand View Post
    Yes. This is what is said in the Code, in your words. . . but look at the phrasing of 250.64(D)(1)(3) especially the highlighted green:



    As written the busbar does not have to be listed. But the connection to the busbar does have to be listed. In the photo in this thread, the green #6 Grounding Electrode Conductor is connected to the LUG (which is listed). The lug, in turn is connected to the busbar.

    It is the second connection, the connection of the listed lug to the busbar that is, in my opinion, included in 250.64(D)(1)(3) as a "Connections to an . . . busbar . . . "

    Clearly, for an effective low impedance electrical path to be accomplished, the LUG must be connected to the "busbar" (a busbar constructed as physically described in 250.64(D)(1)(3)) and I can't see that the language allows an unlisted mechanical bolt and nut, screw or other fastener grabbed off the truck to do the "connection to an . . . busbar . . ."

    The connection to the busbar must be by a "listed connector."

    If the lug was supplied with a fastener that was part of the listing of the lug, you know, like the screws that come with an EGC terminal strip, or the MBJ screw that is included with a panel suitable as Service Equipment, then I believe the NEC rule is satisfied. But the photo in this thread shows generic listed lugs held with generic unlisted fasteners.
    I disagree.
    To me, the bolt and nut have very little to do with the actual connection of the lug to the bar itself.
    The bolt probably doesn't even contact the inside diameter of the drilled hole in the bar.
    It's doing nothing more than keeping pressure held between the listed lug to the listed buss bar.

    If you crimp on a listed 2 hole crimp lug, (which don't come with a bolt and nut), which is what most ground bar hole patterns are drilled for, how would you ever connect the crimp lug to the bussbar without using standard bolts and nuts?

    The buss bar doesn't come with nuts and bolts and neither does the crimp lug.

    Every buss bar I've ever installed comes with holes drilled in it and that's it.
    if there is an option for "listed" nuts and bolts I've never been made aware of it.

    Unless they could prove that the bolts and nuts that they send separately were required to maintain the listing of the lug I don't see how they would be any different than nuts and bolt you'd buy anywhere else.

    They may have a guide on the size, length, and torque setting possibly that are needed.

    Even If the bolts and nuts to bolt the crimp lug onto the bussbar came as an option in a separate bag that you have to install yourself, I don't see how that could be considered to be part of the listed items for the lug or the bussbar seeing as how they aren't bolted to the bar or come with the lug to begin with.

    I may be wrong, but, to me it would be the same type of normal nuts and bolts you could buy anywhere.

    JAP>

  10. #40
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    Quote Originally Posted by Smart $ View Post
    I believe you are just being too nit picky. 'Attachment' of a lug with a machine bolt is the conventionally accepted method of electrical connection. The bolt itself is not the sole connection. Mating surfaces actually provide for most of the connection. Additionally, I have already pointed you to 250.8. You've indicated that you accept the lug as being listed for the purpose. I cannot provide you with additional support or argumentative material. You either accept it as convention does or you can continue to object. If the latter, I'll spectate. But that's all.
    Dang you smart,,, your beat me to it.

    Must have been typing at the same time, I'm just loner winded I guess.

    JAP>

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