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  • CHAPTER38
    WIRING METHODS

    SECTIONE3801
    GENERAL REQUIREMENTS

    E3801.1 Scope.

    This chapter covers the wiring methods for services, feeders and branch circuits for electrical power and distribution. (300.1)

    E3801.2 Allowable wiring methods.

    The allowable wiring methods for electrical installations shall be those listed in Table E3801.2. Single conductors shall be used only where part of one of the recognized wiring methods listed in Table E3801.2. As used in this code, abbreviations of the wiring-method types shall be as indicated in Table E3801.2. [110.8, 300.3(A)]

    TABLE E3801.2

    ALLOWABLE WIRING METHODS

    ALLOWABLE WIRING METHODDESIGNATED ABBREVIATION
    Armored cableAC
    Electrical metallic tubingEMT
    Electrical nonmetallic tubingENT
    Flexible metal conduitFMC
    Intermediate metal conduitIMC
    Liquidtight flexible conduitLFC
    Metal-clad cableMC
    Nonmetallic sheathed cableNM
    Rigid polyvinyl chloride conduit (Type PVC)RNC
    Rigid metallic conduitRMC
    Service entrance cableSE
    Surface racewaysSR
    Underground feeder cableUF
    Underground service cableUSE

    E3801.3 Circuit conductors.

    All conductors of a circuit, including equipment grounding conductors and bonding conductors, shall be contained in the same raceway, trench, cable or cord. [300.3(B)]

    E3801.4 Wiring method applications.

    Wiring methods shall be applied in accordance with Table E3801.4. (Chapter 3 and 300.2)

    TABLE E3801.4 (Chapter 3 and 300.2)

    ALLOWABLE APPLICATIONS FOR WIRING METHODSa, b, c, d, e, f, g, h, i, j, k

    ALLOWABLE APPLICATIONS (application allowed where marked with an “A”)ACEMTENTFMCIMCRMC RNCLFCa, gMCNMSRSEUFUSE
    ServicesAAhAiAAiAAA
    FeedersAAAAAAAAAbAAb
    Branch circuitsAAAAAAAAAAcA
    Inside a buildingAAAAAAAAAAA
    Wet locations exposed to sunlightAAhAAAAAeAe
    Damp locationsAAAdAAAAAA
    Embedded in noncinder concrete in dry locationAAAAj
    In noncinder concrete in contact with gradeAfAAfAj
    Embedded in plaster not exposed to dampnessAAAAAAAAA
    Embedded in masonryAAAfAA
    In masonry voids and cells exposed to dampness or below grade lineAfAAdAfAAAA
    Fished in masonry voidsAAAAAAA
    In masonry voids and cells not exposed to dampnessAAAAAAAAAA
    Run exposedAAAAAAAAAAA
    Run exposed and subject to physical damageAg
    For direct burialAfAfAAfAA

    For SI: 1 foot = 304.8 mm.

    1. a.Liquid-tight flexible nonmetallic conduit without integral reinforcement within the conduit wall shall not exceed 6 feet in length.

    2. b.Type USE cable shall not be used inside buildings.

    3. c.The grounded conductor shall be insulated.

    4. d.Conductors shall be a type approved for wet locations and the installation shall prevent water from entering other raceways.

    5. e.Shall be listed as “Sunlight Resistant.”

    6. f.Metal raceways shall be protected from corrosion and approved for the application. Aluminum RMC requires approved supplementary corrosion protection.

    7. g.RNC shall be Schedule 80.

    8. h.Shall be listed as “Sunlight Resistant” where exposed to the direct rays of the sun.

    9. i.Conduit shall not exceed 6 feet in length.

    10. j.Liquid-tight flexible nonmetallic conduit is permitted to be encased in concrete where listed for direct burial and only straight connectors listed for use with LFNC are used.

    11. k.In wet locations under any of the following conditions:

      1. 1.The metallic covering is impervious to moisture.

      2. 2.A lead sheath or moisture-impervious jacket is provided under the metal covering.

      3. 3.The insulated conductors under the metallic covering are listed for use in wet locations and a corrosion-resistant jacket is provided over the metallic sheath.