1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI/NEMA C29.7-2015Wet-Process Porcelain Insulators High-Voltage Line Post-TypeANSI/NEMA C29.7-2015 American National Standard for Wet-Process Porcelain Insulators High-Voltage Line Post-Type Secretariat: National Electrical Man
2、ufacturers Association Approved: July 31, 2015 Published: October 2, 2015 American National Standards Institute, Inc. 2015 National Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in t
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12、ment. ANSI/NEMA C29.7-2015 Page i AMERICAN NATIONAL STANDARD Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgm
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18、 by National Electrical Manufacturers Association 1300 North 17th Street, Suite 900, Rosslyn, Virginia 22209 2015 National Electrical Manufacturers Association All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Prot
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20、NSI/NEMA C29.7-2015 Page ii 2015 National Electrical Manufacturers Association Foreword (This Foreword is not part of American National Standard C29.7-2015) The principal differences between this edition and the previous (1996) edition are revisions to the color and marking requirements, addition of
21、 more specific requirements for conductor groove dimensions, and a change in the acceptance criteria for the cantilever-strength test. The figures have been revised for clarity. Suggestions for improvement of this standard are welcome. They should be sent by the date of its next scheduled revision (
22、December 31, 2020) to: Senior Technical Director, Operations National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, VA 22209 This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Insulators for Electric Power Lines, C29.
23、 Committee approval of the standard does not necessarily imply that all committee members voted for approval. At the time it approved this standard, the ASC C29 Committee had the following members: A. Jagtiani, Chairman G. Winstanley, Secretary Organization Represented: Name of Representative: Ediso
24、n Electric Institute E. Cleckley B. Freimark M. Garrels R. Kluge K. Reese M. Gray (alt) D. Mar (alt) T. Rao (alt) A. Shkuratkov (alt) Institute of Electrical and Electronic Engineers T. Grisham N. DeSantis A. Jagtiani J. Kuffel T. Shaw J. George (alt) J. Varner (alt) National Electrical Manufacturer
25、s Association A. Baker R. Bernstorf A. Schwalm T. Van Remmen G. Stewart E. Niedospial (alt) P. Maloney (alt) ANSI/NEMA C29.7-2015 Page iii Organization Represented: Name of Representative: Bonneville Power Administration D. Liebhaber J. Havel (alt) Tennessee Valley Authority J. Nelson R. Stargel (al
26、t) Western Area Power Administration R. Clark ANSI/NEMA C29.7-2015 Page iv 2015 National Electrical Manufacturers Association Contents Foreword . ii 1 Scope 1 2 Referenced Standards . 1 3 Definitions 1 4 General 1 5 Material . 1 6 Dimensions and Characteristics 2 7 Marking . 2 8 Sampling, Inspection
27、, and Tests 2 8.1 GENERAL . 2 8.2 DESIGN TESTS 2 8.2.1 Low-Frequency Dry Flashover Test 2 8.2.2 Low-Frequency Wet Flashover Test . 2 8.2.3 Critical Impulse Flashover TestPositive 2 8.2.4 Radio-Influence Voltage Test 2 8.2.5 Thermal Shock Test 3 8.3 QUALITY CONFORMANCE TESTS. 3 8.3.1 Visual and Dimen
28、sional Tests . 3 8.3.2 Porosity Test . 3 8.3.3 Galvanizing Test 3 8.3.4 Cantilever-Strength Test . 3 8.4 ROUTINE TESTS . 4 8.4.1 Routine Flashover Test . 4 8.4.2 Routine Cantilever Test . 4 Appendix . 17 Figures Figure 1 Vertical Tie-Top InsulatorType, F Neck . 7 Figure 2 Vertical Tie-Top InsulatorT
29、ype, N Neck 8 Figure 3 Vertical Clamp Top InsulatorType . 9 Figure 4 Horizontal Clamp Top InsulatorType, Threaded-Base Type . 10 Figure 5 Horizontal Clamp Top Gain Base InsulatorType . 11 Figure 6 ertical Clamp Top Insulator, Cap Dimensions . 12 Figure 7 Horizontal Clamp Top Insulator, Cap Dimension
30、s 13 Figure 8 Cap “GO” and “NO-GO” Gauges . 14 Figure 9 Base Recess and Thread Dimensions 15 Figure 10 Gain Base Details 16 Tables Table 1 Dimensions and Characteristics of Line Post Insulators . 5 Table 2 Neck Designations and Dimensions for Tie-Top Insulators 6 ANSI/NEMA C29.7-2015 Page 1 1 Scope
31、This standard covers high-voltage line post-type insulators made of wet-process porcelain and used in the transmission and distribution of electrical energy. 2 Referenced Standards This standard is intended to be used in conjunction with the latest approved revisions of the following standards: ANSI
32、 C29.1 Test Methods for Electrical Power Insulators ASTM D 1535 Standard Practice for Specifying Color by the Munsell System ASTM A153/A153M Specification for Zinc Coating (Hot Dip) on Iron and Steel Hardware 3 Definitions See Section 2 of ANSI C29.1-1988 for definitions of terms. 4 General 4.1 Insu
33、lators shall conform in all respects to the requirements of this standard. The text and figures supplement each other and shall be considered part of this standard. 4.2 Manufacturers drawings, if furnished, shall show the outline of the insulators, together with all pertinent dimensions. Any variati
34、ons in these dimensions due to manufacturing tolerances shall be shown. 4.3 When specified in the clauses below, the following re-test procedure applies: If only one insulator or metal part fails, or in case the average value fails to comply with the applicable test, a new sample equal to twice the
35、quantity originally submitted to that test shall be subjected to re-testing. If two or more insulators or metal parts fail to comply, or if any failure occurs during the re-testing, the complete lot is considered as not complying with the requirements of this standard. 5 Material 5.1 The insulators
36、shall be made of commercial-grade wet-process porcelain that meets the mechanical and electrical requirements of this standard. 5.2 The porcelain surface of the shells exposed after the assembly shall be glazed for porcelain insulators. NOTEThe most commonly requested color for porcelain insulators
37、is gray. If gray is required, it shall be in accordance with ASTM D 1535, Standard Practice for Specifying Color by the Munsell System, and shall conform to Munsell notation 5BG 7.0/0.4 within the following tolerances: (1) Hue: 12 (3G to 7B) (2) Value: 0.5 (3) Chroma: -0.2 to +0.6 Other colors are a
38、vailable and can be negotiated between purchaser and supplier. ANSI/NEMA C29.7-2015 Page 2 2015 National Electrical Manufacturers Association 5.3 Metal parts shall be made of a commercial grade of malleable iron, ductile iron, or steel. Ferrous parts, other than stainless steel, shall be galvanized
39、in accordance with ASTM A153. The product designed shall consider the different thermal expansion/contraction rates of the component parts. 6 Dimensions and Characteristics 6.1 Figures 1-5 (see pages 8-12) are drawings of insulator classes. Dimensions and characteristics of the insulators shall be i
40、n accordance with these figures and Table 1. 6.2 When specified, neck designations shall be as shown in Table 2. All surfaces that might come in contact with conductors or tie wires must be rounded to prevent abrasion, cracking, or metal fatigue. For tie-top insulators, the length of the top conduct
41、or groove shall not exceed the maximum neck diameter by more than 0.12 inch. The minimum depth of the top conductor groove shall be 0.5 inch for C neck, 0.6 inch for F neck, and 0.81 inch for N neck insulators. 7 Marking Each insulator shall include markings to identify manufacturer and a time/lot r
42、eference (as a minimum, the month and year that the item was produced). The marking shall be legible and durable. 8 Sampling, Inspection, and Tests 8.1 GENERAL Tests described in 8.2 shall be required only on insulators of new designs. Tests described in 8.3 shall be required on each lot of insulato
43、rs. Tests described in 8.4 shall be made on each insulator. 8.2 DESIGN TESTS 8.2.1 Low-Frequency Dry Flashover Test Three insulators shall be tested in accordance with 4.2 of ANSI C29.1, “Low-Frequency Dry Flashover Test.” Failure of the average dry flashover value of these three insulators to equal
44、 or exceed 95% of the rated dry flashover value, as given in Table 1, shall constitute failure to meet the requirements of this standard. 8.2.2 Low-Frequency Wet Flashover Test Three insulators shall be tested in accordance with 4.3 of ANSI C29.1, “Low-Frequency Wet Flashover Test.” Failure of the a
45、verage wet flashover value of these three insulators to equal or exceed 90% of the rated wet flashover value, as given in Table 1, shall constitute failure to meet the requirements of this standard. 8.2.3 Critical Impulse Flashover TestPositive Three insulators shall be subjected to the critical imp
46、ulse flashover test, positive, and tested in accordance with 4.7 of ANSI C29.1, “Critical Impulse Flashover TestsPositive.” Failure of the average critical impulse flashover value of these three insulators to equal or exceed 92% of the rated critical impulse flashover value, as given in Table 1, sha
47、ll constitute failure to meet the requirements of this standard. 8.2.4 Radio-Influence Voltage Test Three insulators shall be tested in accordance with 4.9 of ANSI C29.1, “Radio-Influence Voltage Test.” If one or more of these insulators fails to meet the requirements given in Table 1, three additio
48、nal insulators ANSI/NEMA C29.7-2015 Page 3 shall be selected and tested. Failure of one or more of these additional insulators shall constitute failure to meet the requirements of this standard. 8.2.5 Thermal Shock Test Three insulators shall be tested for 10 complete cycles in accordance with 5.5 o
49、f ANSI C29.1, “Thermal Shock Test.” The temperature of the hot water bath shall be approximately 150F (66C), and the temperature of the cold water bath shall be approximately 39F (4C). If one or more insulators fails, three additional insulators shall be tested. Failure of one or more of these additional insulators shall constitute failure to meet the requirements of this standard. 8.3 QUALITY CONFORMANCE TESTS1 8.3.1 Visual and Dimensional Tests Conformity with 5.2 may be determined by visual inspection. All insulators not conforming
