1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI C80.3-2015Electrical Metallic TubingSteel (EMT-S)ANSI C80.3-2015 American National Standard for Electrical Metallic TubingSteel (EMT-S) Secretariat: National Electrical Manufacturers Association Approved: December 14, 2015 A
2、merican National Standards Institute, Inc. ANSI C80.3-2015 Page ii NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessari
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18、irm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute, Inc. Published by National Electrical Manufacturers Association 1300 North 17thStreet, Suite 900 Rosslyn
19、, VA 22209 2015 National Electrical Manufacturers Association All rights reserved including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Co
20、nventions. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Printed in the United States of America ANSI C80.3-2015 Page ii 2015 National Electrical Manufacturers Association ANSI C80.3-2
21、015 Page iii 2015 National Electrical Manufacturers Association CONTENTS Page 1 Scope 1 2 Normative References . 1 3 Definitions 2 4 Units of Measurements . 2 5 General Requirements. 2 5.1 Circular cross section . 2 5.2 Wall Thickness 2 5.3 Interior surface 2 5.4 Welding . 2 5.5 Cleaning 2 5.6 Prote
22、ctive coating for corrosion resistance 2 5.7 Surface treatment . 2 6 Detailed Requirements 3 6.1 Exterior coating . 3 6.1.1 Zinc Coating 3 6.1.2 Alternate corrosion resistant coating (ACRC) . 3 6.2 Interior coating 3 6.3 Chamfering . 3 6.4 Identification 3 6.5 Dimensions . 3 6.6 Elbows 3 7 Test Proc
23、edures . 3 7.1 Bending properties 3 7.1.1 Ductility of steel . 3 7.1.2 Ductility of coatings at ambient temperature . 3 7.2 Thickness of zinc coating . 4 7.3 Alternate corrosion resistant coatings (ACRC) . 4 7.4 Performance requirement of organic coating for use on interior surface . 4 8 Examination
24、 of Product. 4 8.1 Place of inspection 4 8.2 Visual inspection of tubing 4 8.3 Visual inspection of elbows 4 8.4 Retest . 5 9 Markings . 5 9.1 General . 5 9.2 Nonmetallic alternate corrosion resistant coating temperature marking 5 ANSI C80.3-2015 Page iv 2015 National Electrical Manufacturers Associ
25、ation 9.3 Supplementary coating marking . 5 TABLES Table 1 Dimensions and weights for EMT-S . 6 Table 2 Minimum dimensions for 90-degree elbows 7 ANSI C80.3-2015 Page v 2015 National Electrical Manufacturers Association Foreword (This foreword is not part of American National Standard C80.3-2015.) T
26、his standard was developed by the Accredited Standards Committee on Raceways for Electrical Wiring Systems, C80. The objective of the committee is to produce a comprehensive specification that would establish uniform dimensions and standard construction requirements for electrical rigid steel condui
27、t, steel electrical metallic tubing, electrical intermediate metal conduit, and electrical aluminum rigid conduit raceway products and their associated components. The standard was originally approved in 1950 and revised in 1953, 1959, 1963, 1966, 1977, 1983, 1991, 1994, 2005, and 2015. Suggestions
28、for improvement of this standard will be welcomed. They should be sent to the National Electrical Manufacturers Association, 1300 North 17th Street, Suite 900, Rosslyn, Virginia 22209. This standard was processed and approved for submittal to ANSI by the Accredited Standards Committee (ASC) on Racew
29、ays for Electrical Wiring Systems, ASC C80. Committee approval of the standard does not necessarily imply that all committee members voted for its approval. At the time it approved this standard, the C80 Committee comprised the following members: M. J. Brett, Jr., Chair J. G. Solis, Secretary Organi
30、zations Represented Name of Representative Western Tube & Conduit Corporation J. Bloom Republic Conduit P. Douglas Wheatland Tube Company M. J. Brett, Jr. International Association of Electrical Inspectors D. Humphrey International Brotherhood of Electrical Workers P. Hickman National Electrical Con
31、tractors Association M. Johnston Appleton Group S. Blais Allied Tube & Conduit, a part of Atkore International E. Thompson Allied Tube & Conduit, a part of Atkore International R. Horner R & N Associates R. Loyd SAPA Extrusion North America H. E. Harper, Jr. The following members of the NEMA Steel C
32、onduit & Electrical Metallic TubingCodes/Communications/Technical Committee worked on this standard prior to its publication: J. Burris, Co-Chair R. Horner, Co-Chair J. G. Solis, Secretary J. Andre J. Bloom M. Brett P. Douglas L. Easter D. Kendall C. Leonardo-Javier R. Loyd D. Markus R. Szkola E. Th
33、ompson C. Wood M. Ziegler ANSI C80.3-2015 Page vi 2015 National Electrical Manufacturers Association ANSI C80.3-2015 Page 1 2015 National Electrical Manufacturers Association 1 Scope This standard covers the requirements for steel electrical metallic tubing, for use as a raceway for wires or cables
34、of an electrical system. Finished tubing is typically furnished in nominal 10-ft (3.05-m) lengths. It is protected on the exterior surface with a metallic zinc coating or alternate corrosion protection coating (see UL 797 for alternate corrosion protection coating requirements) and on the interior s
35、urface with a zinc or organic coating. This standard also covers electrical metallic tubing elbows. Properly assembled systems of EMT-S, manufactured in accordance with this standard, and other identified fittings provide for the electrical continuity required of an equipment grounding conductor. 2
36、Normative References The following standards contain provisions that, through reference in this text, constitute requirements of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on t
37、his American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below unless otherwise specified. ASTM A239 14 Standard Practice for Locating the Thinnest Spot in a Zinc (Galvanized) Coating on Iron or Steel Articles 1, 2 A
38、STM B117 11 Standard Practice for Operating Salt Spray (Fog) Apparatus ASTM B499 96 (2002) Standard Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals ASTM B499 -09 Standard Test Method for Measurement of Coating Thicknesses by th
39、e Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals ASTM D638 14 Standard Test Method for Tensile Properties of Plastics ASTM D1654 08 Standard Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments ASTM D2444 99(2010) Standard Test Method for Dete
40、rmination of the Impact Resistance of Thermoplastic Pipe and Fittings by Means of a Tup (Falling Weight) ASTM D3359 09e2 Standard Test Methods for Measuring Adhesion by Tape Test ASTM G151 10 Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light S
41、ources ASTM G153 13 Standard Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials ASTM G155 13 Standard Practice for Operating Xenon Arc Light Apparatus for Exposure of Nonmetallic Materials UL 797 Electrical Metallic Tubing Steel ANSI C80.3-2015 Page 2 20
42、15 National Electrical Manufacturers Association 3 Definitions 3.1 Electrical metallic tubingsteel (EMT-S): A steel raceway of circular cross section designed for the physical protection and routing of conductors and cables for use as an equipment grounding conductor. 3.2 Elbow: A manufactured curve
43、d section of EMT. 3.3 Alternate corrosion resistant coating (ACRC): A coating, other than one consisting solely of zinc, that, upon evaluation, has demonstrated the ability to provide the level of corrosion resistance required on the exterior of tubing. It is not prohibited that the coatings include
44、 zinc. (See UL 797.) 4 Units of Measurements The values stated in English units are to be regarded as the standard. The metric (SI) units are exact conversions. 5 General Requirements 5.1 Circular cross section EMT-S shall have a circular cross section sufficiently accurate to permit the application
45、 of identified EMT-S fittings. 5.2 Wall thickness The wall thickness shall be uniform throughout. 5.3 Interior surface The interior surface shall be smooth and free from injurious defects that compromise the intended use of the electrical raceway. 5.4 Welding The welding of all seams shall be contin
46、uous and done in a workmanlike manner. 5.5 Cleaning The tubing shall be adequately cleaned before the application of the protective coating. The cleaning process shall leave the exterior and interior surfaces of the tubing in such a condition that the protective coating shall be smooth and adhere fi
47、rmly. 5.6 Protective coating for corrosion resistance 5.6.1 The exterior surface shall be either thoroughly and evenly coated with metallic zinc or protected with an ACRC. 5.6.2 The interior surface shall be protected by a zinc or organic coating. The interior coating shall have a smooth continuous
48、surface. An occasional variation due to uneven flow of coating shall be acceptable. 5.7 Surface treatment Any surface treatment not exceeding 0.00015 inch (0.0038 mm) that is employed as a topcoat or conversion coating is not required to meet the requirements for an ACRC or organic coating. ANSI C80
49、.3-2015 Page 3 2015 National Electrical Manufacturers Association 6 Detailed Requirements 6.1 Exterior coating 6.1.1 Zinc coating The zinc coating thickness on the outside surface shall be equivalent to a minimum thickness of 0.0008 in. (0.02 mm), as tested in accordance with 7.2. 6.1.2 Alternate corrosion resistant coating (ACRC) (See UL 797.) 6.2 Interior coating 6.2.1 The zinc coating shall be tested in accordance with 7.1.2. 6.2.2 The organic coating shall not soften at a temperature of 120F (49C) and shall be sufficiently elastic to c
