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Article 354

  1. Nonmetallic Underground Conduit with Conductors: Type NUCCPart I. General
    1. Scope. This article covers the use, installation, and construction specifications for nonmetallic underground conduit with conductors (NUCC).
    2. Definition.
    Nonmetallic Underground Conduit with Conductors (NUCC). A factory assembly of conductors or cables inside a nonmetal‐ lic, smooth wall raceway with a circular cross section.
  2. Aboveground, except as prohibited in 354.12, where encased in not less than 50 mm (2 in.) of concrete

354.12 Uses Not Permitted. NUCC shall not be used in the following:

  1. In exposed locations
  2. Inside buildingsException: The conductor or the cable portion of the assembly, where suitable, shall be permitted to extend within the building for termina‐ tion purposes in accordance with 300.3.
  3. In any hazardous (classified) location, except as permit‐ ted by other articles of this Code

354.20 Size.

  1. Minimum. NUCC smaller than metric designator 16 (trade size 1∕2) shall not be used.
  2. Maximum. NUCC larger than metric designator 103 (trade size 4) shall not be used.

Informational Note: See 300.1(C) for the metric designators and trade sizes. These are for identification purposes only and do not relate to actual dimensions.

354.22 Number of Conductors. The number of conductors or cables shall not exceed that permitted by the percentage fill in Table 1, Chapter 9.

354.24 Bends — How Made. Bends shall be manually made so that the conduit will not be damaged and the internal diam‐ eter of the conduit will not be effectively reduced. The radius of the curve of the centerline of such bends shall not be less than shown in Table 354.24.

354.26 Bends — Number in One Run. There shall not be more than the equivalent of four quarter bends (360 degrees total) between termination points.

354.28 Trimming. For termination, the conduit shall be trim‐ med away from the conductors or cables using an approved method that will not damage the conductor or cable insulation or jacket. All conduit ends shall be trimmed inside and out to remove rough edges.

Table 354.24 Minimum Bending Radius for Nonmetallic Underground Conduit with Conductors (NUCC)

354.6 Listing Requirements. NUCC and associated fittings                                                                                                                                

shall be listed.

Part II. Installation

354.10 Uses Permitted. The use of NUCC and fittings shall

Conduit Size Minimum Bending Radius

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Metric

161∕225010
213∕430012

Designator Trade Size mm in.

be permitted in the following:27135014
(1) For direct burial underground installation (For minimum3511∕445018
cover requirements, see Table 300.5 and Table 300.504111∕250020
under Rigid Nonmetallic Conduit.)53265026
(2) Encased or embedded in concrete6321∕290036
(3) In cinder fill783120048
(4) In underground locations subjectto severe corrosive1034150060
image

influences as covered in 300.6 and where subject to chem‐ icals for which the assembly is specifically approved

354.46 ARTICLE 355 — REINFORCED THERMOSETTING RESIN CONDUIT: TYPE RTRC

354.46 Bushings. Where the NUCC enters a box, fitting, or other enclosure, a bushing or adapter shall be provided to protect the conductor or cable from abrasion unless the design of the box, fitting, or enclosure provides equivalent protection.

Informational Note: See 300.4(G) for the protection of conduc‐ tors size 4 AWG or larger.

354.48 Joints. All joints between conduit, fittings, and boxes shall be made by an approved method.

354.50 Conductor Terminations. All terminations between the conductors or cables and equipment shall be made by an approved method for that type of conductor or cable.

354.56 Splices and Taps. Splices and taps shall be made in junction boxes or other enclosures.

354.60 Grounding. Where equipment grounding is required, an assembly containing a separate equipment grounding conductor shall be used.

Part III. Construction Specifications

354.100 Construction.

  1. General. NUCC is an assembly that is provided in contin‐ uous lengths shipped in a coil, reel, or carton.
  2. Nonmetallic Underground Conduit. The nonmetallic underground conduit shall be listed and composed of a mate‐ rial that is resistant to moisture and corrosive agents. It shall also be capable of being supplied on reels without damage or distortion and shall be of sufficient strength to withstand abuse, such as impact or crushing, in handling and during installation without damage to conduit or conductors.
  3. Conductors and Cables. Conductors and cables used in NUCC shall be listed and shall comply with 310.10(C). Conduc‐ tors of different systems shall be installed in accordance with 300.3(C).
  4. Conductor Fill. The maximum number of conductors or cables in NUCC shall not exceed that permitted by the percent‐ age fill in Table 1, Chapter 9.

354.120 Marking. NUCC shall be clearly and durably marked at least every 3.05 m (10 ft) as required by 110.21. The type of conduit material shall also be included in the marking.

Identification of conductors or cables used in the assembly shall be provided on a tag attached to each end of the assembly or to the side of a reel. Enclosed conductors or cables shall be marked in accordance with 310.120.

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