• Code Quiz: Sizing the Grounding Conductor for a Single Raceway

    NEC rules for sizing the grounding conductor for a single raceway
    Aug. 7, 2014
    2 min read

    Why is the term “grounded conductor” included in the heading of new Table 250.102(C)(1)?

    A. It is an error and will be corrected in newer printings of the 2014 NEC.

    B. Because the grounded conductor is used as a bonding jumper.

    C. In the case of an installation of a service for a single load installed in a single raceway, such as a 460V, 3-phase motor, which has no calculated neutral load per 220.61, this is a method for calculating the size of the required grounded conductor in accordance with 250.24(C)(1), where supplied by a grounded electric utility system.

    D. Because there was no substantiation to include the term in Table 250.66.

    Find the Answer

    Answer: C

    Bonding requirements are outlined in Part V of Art. 250. Section 250.102(C)(1) notes how to size bonding jumpers and conductors for supply conductors in a single raceway or cable. In the case of an installation of a service for a single load installed in a single raceway, such as a 460V, 3-phase motor, which has no calculated neutral load per 220.61, this is an example of how to comply with the requirement of 250.24(C)(1). This is a method for calculating the size of the required grounded conductor where supplied by an electric utility system that is grounded.

    Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at [email protected].

    About the Author

    Steven Owen

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