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Steel Conduit and Electrical Metallic Tubing


The Steel Conduit and Electrical Metallic Tubing Section develops technical standards and guidelines for its products.

Scope

  • Rigid steel conduit, including elbows, threaded couplings, and nipples customarily furnished on or with rigid steel conduit.
  • Steel electrical metallic tubing, including elbows customarily furnished with steel electrical metallic tubing.
  • Steel intermediate metal conduit including elbows, threaded coupling, and nipples customarily furnished on or with steel intermediate metal conduit.

Click here for detailed product scope information.

Learn more about Section Activities & Services by clicking on any of the following links:

Technical Activities Government Affairs
Market Economics Membership
Related Standards Upcoming Meetings & Events
Section Committees Section Partners
Section Forum Electrical Circuit Protective Systems

Technical Activities

Standards play a vital part in the design, production, and distribution of products destined for both national and international com­merce. Sound technical standards benefit the user, as well as the manufacturer, by improving safety, bringing about economies in product, eliminating misunderstandings between manufacturer and purchaser, and assisting the pur­chaser in selecting and obtaining the proper product for his particular need.

NEMA devotes much of its time, effort, and resources to voluntary standardization activities. NEMA standards are offered and recommended to become American National Standards under the procedures of the American National Standards Institute, usually under the canvass method. This decision rests with the particular subdivision or subdivisions concerned. NEMA standards are also often submitted for consideration as IEC standards components or references. It is the intent of the association to continue its support of these, and many more, activities as the best method to continue providing sound and safe electrical products for the use of all.

Key technical activities include:

  • Revising and maintaining the following NEMA standards:
    • NEMA RN 1, Polyvinyl Chloride (PVC) Externally Coated Galvanized Rigid Steel Conduit and Intermediate Metal Conduit;
    • NEMA RN 2, Packaging of Master Bundles for Steel Rigid Conduit, Intermediate Metal Conduit (IMC) and Electrical Metallic Tubing (EMT); and
    • NEMA RN 3, Product Identification Numbers for Metallic Tubular Conduit Products for Use with Bar Coding and Electronic Data Interchange Applications.
  • Participation in the Revising and Maintaining through participation in ASC C80 on the following American National Standards:
    • ANSI C80.1, Electric Rigid Steel Conduit (ERSC);
    • ANSI C80.3, Electrical Metallic Tubing (EMT-S);
    • ANSI C80.5, Elecrical Rigid Aluminum Conduit-Aluminum (ERMC-A);
    • ANSI C80.6, Intermediate Metal Conduit (EIMC).
  • Maintaining work of CANENA Technical Harmonization Subcommittee 23A
    • UL 797; C22.2 NO. 83.1; and NMX-J-536-ANCE
    • UL 6A; C22.2 NO. 45.2; and NMX-J-576-ANCE
  • Maintaining the following NEMA Technical Bulletins:
    • TTGR-N; The Grounding System That Works—Steel Conduit (Electrical Metallic Tubing, Intermediate Metal Conduit and Galvanized Rigid);
    • 2189: User Guide to Product Specifications for Metal Electrical Conduit and Tubing;
    • Annular Space Protection; Annular Space Protection of Openings Created by Penetrations of Tublular Steel Conduit - A Review of UL Special Services Investigation File NC546 Project 90NK11650
    • Bulletin No. 96; UL and NEC Requirements for Corrosion Protection of Galvanized Steel Conduit and Electrical Metallic Tubing
    • Bulletin No. 97; Rigid Metal Conduit, Intermediate Metal Conduit and Electrical Metallic Tubing: Proven to Meet the NEC® Requirements for Equipment Grounding
  • Maintaining the following White Papers:
    • Hexavalent Chrome on Steel Conduit;
    • Lead in Steel Conduit
  • Maintaining the following NEMA Field Represetative Presentations:
    • Grounding; Evaluation of Steel Conduit and EMT as Equipment Grounding Conductors
    • Corrosion Protection; UL & NEC Requirements for Corrosion Protection of RMC, IMC, EMT
  • Maintaining active involvement in the National Electrical Code® process.

Technical Committee:

  1. Code/Communication/Technical Committee

    Purpose:
    The Code/Communication/Technical Committee develops code proposal for the National Electrical Code, International Code Council and other codes and develops and manages NEMA and UL standards for steel conduit. The Committee also develops marketing and communication activities for the Group.

    Leadership:

    Raymond Horner, Co-Chair
    Allied Tube Conduit
    RHorner@atkore.com

    Jay Burris, Co-Chair
    Wheatland Tube Company
    Jay.Burris@zekelman.com

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Government Affairs

Through NEMA, the section develops industry positions on legislative and regulatory initiatives that may affect member products, markets, and customers. NEMA's work has resulted in contributions to public policy development and in promoting competitiveness, technological progress, and public safety. On the Government Affairs homepage members can search for and e-mail federal representatives to convey opinions regarding energy policy or other issues related to the electroindustry.

NEMA Government Affairs provides specific services to its members and information in the areas of Environment, Health & Safety; Energy; and International Trade & Commerce.

To learn more about the Section's positions, click on White Papers on Hexavalent Chrome in Steel Conduit and Lead in Steel Conduit.

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Membership

Membership in NEMA is open to any firm actively engaged in the manufacture in North America of a product within the NEMA scope and for sale in the open market. Membership of foreign firms is subject to product section policies and NEMA Board of Governors approval.

NEMA operates on a fee-for-service basis. Each product section establishes its projects and activities and approves an annual operating budget. Visit Joining NEMA for more information on membership.

Electrical Circuit Protective Systems

UL recently changed the Guide Information for UL Category FHIT, Electrical Circuit Protective Systems (see Guide Information shown below).  These systems are published in the UL Fire Resistance Directories.  The change applies to the type of systems that are constructed with special fire-resistive cables installed inside steel conduit or raceway.  The change, indicated in yellow, states that “unless specifically stated in the design, all electrical circuit protective system components that come into contact with fire-resistive cables shall have an interior coating free of zinc.  This includes raceways, couplings, connectors, boxes, conduit bodies, and the like.”

Electrical Circuit Protective Systems are very specialized systems used in applications such as fire pumps, emergency systems, fire alarm and tunnels.  It is the cable manufacturer that tests their cables with specific system components in order to achieve a fire-rating for that system. Typically, fire-resistive cable manufacturers have tested their cables in EMT and if their cables passed the test in EMT, they were allowed to be used in IMC or rigid steel conduit as well.

 It is important to note that this change was not due to any quality issue with conduit.  One of the manufacturers of the fire-resistive cables was testing their cables inside of hot-dip galvanized rigid conduit and discovered a compatibility issue between the copper conductors and the zinc on the interior of the rigid steel conduit.  Although the cable manufacturer reported an issue only with a conduit with a hot-dip galvanized interior, UL is taking a conservative stance and is requiring that components used in these systems have zinc-free interior coatings, while they conduct research on the issue.

EMT and IMC manufactured by members of NEMA Section 5RN (Steel Conduit and EMT) are listed to UL 797 and UL 1242 respectively and do not have zinc interior coatings.  The interior coatings are specialized organic coatings that provide a high degree of corrosion protection and easy wire-pulling. 

We understand that UL has initiated a research program and we are hopeful their research results will lead to a less-restrictive requirement on the interiors of fittings and boxes. 

In the meantime, users can contact the manufacturers of the fire resistive cables for information as to the designs of Electrical Circuit Protective Systems they have tested and that have passed the requirements.  These manufacturers are listed in the UL Fire Resistive Directory.

NEMA Section 5RN members may also be contacted for update information.  Contacts are shown below:

 

Related Manufacturers

Related Standards

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