1、 ANSI/NEMA GR 1-2007 GROUNDING ROD ELECTRODES AND GROUNDING ROD ELECTRODE COUPLINGS Approved as an American National Standard ANSI Approval Date: July 17, 2007 NEMA Standards Publication GR 1-2007 Grounding Rod Electrodes and Grounding Rod Electrode Couplings Published by: National Electrical Manufa
2、cturers Association 1300 North 17th Street, Suite 1752 Rosslyn, VA 22209 www.nema.org Copyright 2007 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection
3、 of Literary and Artistic Works, and the International and Pan American Copyright Conventions. Copyright 2007 by the National Electrical Manufacturers Association. NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the de
4、velopment and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. The National Electrical Manufacturers Association (NEMA) standards and guideline publicatio
5、ns, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the proces
6、s and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications.
7、 NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no gua
8、ranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the performance of any
9、individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed b
10、y any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topi
11、c covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA does not certif
12、y, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safetyrelated information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the
13、statement. GR 1-2007 Page i Copyright 2007 by the National Electrical Manufacturers Association. CONTENTS Page Foreword . iv Section 1 GENERAL . 1 1.1 Scope. 1 1.2 Normative References. 1 1.3 Units of Measurement . 2 1.4 Definitions 2 Section 2 COPPER BONDED GROUND ROD ELECTRODES. 3 2.1 Steel Core P
14、roperties 3 2.2 Copper Thickness 3 2.3 Length 3 2.4 Ground Rod Electrode Diameters . 3 2.5 Threads 3 2.6 End Configurations 4 2.7 Adhesion 5 2.7.1 Test Method 5 2.7.2 Evaluation 5 2.8 Ductility 5 2.8.1 Test Method 5 2.8.2 Evaluation 5 2.9 Finish . 5 2.10 Straightness. 5 2.10.1 Test Method 5 2.10.2 E
15、valuation 6 2.11 Markings 6 Section 3 ZINC COATED GROUND ROD ELECTRODES 7 3.1 Steel Core Properties 7 3.2 Zinc Coating 7 3.2.1 Coating Method. 7 3.2.2 Thickness 7 3.2.3 Measurement 7 3.3 Length 7 3.4 Ground Rod Electrode Diameters . 7 3.5 Adhesion 7 3.5.1 Test Method 8 3.5.2 Evaluation 8 3.6 Finish
16、. 8 3.7 Straightness. 8 3.7.1 Test Method 8 3.7.2 Evaluation 8 3.8 End Configurations 8 3.9 Markings 9 Section 4 STAINLESS STEEL GROUND ROD ELECTRODES 10 4.1 Steel Properties . 10 4.2 Length 10 4.3 Ground Rod Electrode Diameters . 10 4.4 Finish . 10 4.5 Straightness. 10 4.5.1 Test Method 10 4.5.2 Ev
17、aluation 11 4.6 Markings 11 GR 1-2007 Page ii Copyright 2007 by the National Electrical Manufacturers Association. Section 5 COUPLINGS FOR COPPER BONDED GROUND ROD ELECTRODES . 12 5.1 Physical Properties 12 5.1.1 Surface Condition 12 5.1.2 Material 12 5.2 Construction 12 5.2.1 Length . 12 5.2.2 Appl
18、ication Diameter . 12 5.3 Performance 13 5.3.1 Conductivity. 13 5.3.2 Impact 13 5.3.3 Pullout . 13 5.3.4 Bend 13 5.3.5 Mechanical Strength . 14 5.4 Markings 14 Section 6 COUPLINGS FOR ZINC-COATED GROUND ROD ELECTRODES 15 6.1 Physical Properties 15 6.1.1 Surface Condition 15 6.1.2 Material 15 6.2 Con
19、struction 15 6.2.1 Length . 15 6.2.2 Threadless Ground Rod Electrode Couplings 15 6.3 Performance 15 6.3.1 Conductivity. 15 6.3.2 Impact 16 6.3.3 Bend 16 6.3.4 Mechanical Strength . 16 6.4 Markings 16 Section 7 COUPLINGS FOR STAINLESS STEEL GROUND ROD ELECTRODES. 17 7.1 Physical Properties 17 7.1.1
20、Surface Condition 17 7.1.2 Material 17 7.2 Construction 17 7.2.1 Length . 17 7.2.2 Application Diameter . 17 7.2.3 Threadless Ground Rod Electrode Couplings 17 7.3 Performance 18 7.3.1 Conductivity. 18 7.3.2 Impact 18 7.3.3 Bend 18 7.3.4 Mechanical Strength . 19 7.4 Markings 19 Tables 2-1 Finished D
21、iameter Ranges for Copper Bonded Ground Rod Electrodes . 3 2-2 Thread Specifications 4 2-3 End Point Configurations. 4 3-1 Finished Diameter Ranges for Zinc Coated Ground Rod Electrodes . 7 3-2 End Point Configurations. 9 4-1 Finished Diameter Ranges for Solid Stainless Steel Ground Rod Electrodes 1
22、0 4-2 End Point Configurations. 11 5-1 Coupling Thread Sizes for Threaded Copper Bonded Ground Rod Electrodes 12 GR 1-2007 Page iii Copyright 2007 by the National Electrical Manufacturers Association. 5-2 Application Diameters for Threadless Couplings for Threadless Copper Bonded Ground Rod Electrod
23、es 13 6-1 Application Diameters for Threadless Couplings For Threadless Zinc-Coated Ground Rod Electrodes 15 7-1 Coupling Thread Sizes for Threaded Stainless Steel Ground Rod Electrodes . 17 7-2 Application Diameters for Threadless Couplings for Threadless Stainless Steel Ground Rod Electrodes 18 Fi
24、gures 2-1 Thread Specification 4 2-2 End Configuration 4 2-3 Apparatus for Straightness Test . 6 3-1 End Configuration 8 3-2 Alternative End Configurations 9 4-1 End Configuration 11 GR 1-2007 Page iv Copyright 2007 by the National Electrical Manufacturers Association. Foreword This Standards Public
25、ation provides practical information concerning construction, test, performance, and manufacture of ground rod electrodes and ground rod electrode couplings. This standard is intended for use by the electrical industry to provide guidelines for the manufacture and proper application of these product
26、s, and to promote the benefits of repetitive manufacture and widespread product availability. One of the primary purposes of this Standards Publication is to encourage the manufacture and utilization of products, which, in themselves, function in accordance with these standards. While some sections
27、of this publication are intended to eliminate misunderstandings between manufacturers and users, all sections, when applied properly, contribute to safety in one way or another. The proper manufacture of ground rod electrodes and ground rod electrode couplings is, however, only one consideration in
28、promoting the safe utilization of electricity. Other safety considerations, including environmental conditions, system design, equipment selection and application, installation, operating practices and maintenance, involve the joint efforts of the system designer, the various equipment manufacturers
29、, the installer, and the user. Information is provided herein to assist in proper selection and use. This Standards Publication covers design and performance requirements for ground rod electrodes and ground rod electrode couplings, and provides recommendations for their selection and use under norm
30、al or certain specific conditions. These standards have been promulgated with a view of promoting safety to persons and property when products conforming to them are selected, installed, and maintained in accordance with the National Electrical Codeand/or the National Electrical Safety Code. NEMA St
31、andards Publications are periodically reviewed to meet changing conditions and technical progress, and the latest edition should be utilized. Purchasers will be notified as to when revisions take place and will be provided an opportunity to acquire these when available. Comments from users of this s
32、tandards publication are welcome. They should be sent to: Vice President, Technical Services National Electrical Manufacturers Association 1300 North 17th Street, Suite 1752 Rosslyn, VA 22209 This Standards Publication was developed by the Electrical Connector Section of the National Electrical Manu
33、facturers Association. GR 1-2007 Page 1 Copyright 2007 by the National Electrical Manufacturers Association. Section 1 GENERAL 1.1 SCOPE This Standards Publication applies to ground rod electrodes and ground rod electrode couplings that function in accordance with the National Electrical Code (NFPA
34、70-2005) and/or the National Electrical Safety Code (ANSI C2-2002). Included are materials, construction, and performance of copper bonded ground rod electrodes, zinc-coated ground rod electrodes, and stainless steel clad ground rod electrodes. This standards publication also includes information fo
35、r electrode products that have been successfully used for many years but are not defined within the National Electrical Code or the National Electrical Safety Code. The items described in this Standards Publication are defined in Section 1. 1.2 NORMATIVE REFERENCES This NEMA Standards Publication re
36、presents the results of research and investigation by the members of NEMA, its Sections and Committees. It has been developed through consultation among manufacturers, users, and national engineering societies. This publication references the following standards (all referenced documents use the lat
37、est document date): American Society for Testing and Materials 100 Barr Harbor Drive Conshohocken, PA 19428-2959 ASTM A123/A123M-01 Standard Specification for Zinc (Hot Dip Galvanized) Coatings of Iron and Steel Products ASTM A153/A153M-01 Standard Specification for Zinc Coatings (Hot-Dip) on Iron a
38、nd Steel Hardware ASTM A276-05a Standard Specification for Stainless Bars and Shapes ASTM A370-97a Standard Test Methods and Definitions for Mechanical Testing of Steel Products ASTM E376-96 Standard Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Test Me
39、thods Institute of Electrical and Electronic Engineers 445 Hoes Lane Piscataway, NJ 08854 ANSI/IEEE C2-2002 National Electrical Safety Code National Fire Protection Association, Inc. One Batterymarch Park Quincy, MA 02169 ANSI/NFPA 70-2005 National Electrical CodeUnderwriters Laboratories, Inc. 333
40、Pfingsten Road Northbrook, IL 60062 ANSI/UL 467-1993 Standard for Grounding and Bonding Equipment GR 1-2007 Page 2 Copyright 2007 by the National Electrical Manufacturers Association. 1.3 UNITS OF MEASUREMENT The primary units of measure in this Standards Publication are based on the metric dimensio
41、ns with conventional inch-pound system in parentheses, which is commonly accepted and used by the electrical construction industry. 1.4 DEFINITIONS adhesion: The physical bond between the applied metal and the core metal. copper bond: The physical bond between the copper and the core metal. coupling
42、: A connecting device for mechanically and electrically joining two ground rod electrodes in series. ground rod electrode: A rod type device that establishes an electrical connection to the earth and is capable of being driven. zinc coating: The layer of zinc around the core metal. GR 1-2007 Page 3
43、Copyright 2007 by the National Electrical Manufacturers Association. Section 2 COPPER BONDED GROUND ROD ELECTRODES 2.1 STEEL CORE PROPERTIES Upon inspection of the steel core, there shall be minimal signs of pitting and erosion. There shall be no gashes or cracks that protrude slivers from the surfa
44、ce of the electrode. The steel core, when tested in accordance with ASTM A370, shall have a tensile strength of not less than 552 MPa (80,000 lb per square-inch) and a Rockwell hardness of no less than B80. 2.2 COPPER THICKNESS The copper thickness shall not be less than 0.25 mm (0.010 in.) for grou
45、nd rod electrodes 12.7 mm (0.50 in.) or greater in diameter. The copper thickness shall be measured with a properly calibrated eddy-current (electromagnetic) device. The device shall be used in accordance with the manufacturers instructions, and by following the standard practice for measuring coati
46、ng thickness described in ASTM E376. 2.3 LENGTH Ground rod electrodes shall have a minimum total length of 2.44 m (8 ft). They shall have a length as specified with a 0 tolerance. 2.4 GROUND ROD ELECTRODE DIAMETERS Finished ground rod electrodes for the trade sizes listed in Table 2-1 shall be cold
47、drawn and fall within the specified finished diameter ranges. Table 2-1 FINISHED DIAMETER RANGES FOR COPPER BONDED GROUND ROD ELECTRODES Finished Diameter Range Threaded Threadless Trade Size Minimum Maximum Minimum Maximum Inches mm (in.) mm (in.) mm (in.) mm (in.) 1/2* 12.70 0.500 12.90 0.507 12.7
48、0 0.500 12.90 0.507 5/8 14.10 0.555 14.35 0.565 14.10 0.555 14.35 0.565 3/4 17.09 0.673 17.35 0.683 17.09 0.673 17.35 0.683 1 23.04 0.907 23.29 0.917 23.04 0.907 23.29 0.917 *An L or is typically used to indicate minimum 12.70 mm (0.500 in.) diameter. 2.5 THREADS Threads on copper bonded, sectional
49、type ground rod electrodes shall be rolled onto both ends after copper bonding, and shall conform to the specifications in Figure 2-1 and Table 2-2. GR 1-2007 Page 4 Copyright 2007 by the National Electrical Manufacturers Association. B B A A Figure 2-1 THREAD SPECIFICATION Table 2-2 THREAD SPECIFICATIONS Trade Size Inches Dimension A Thread B Profile mm (+3.2, -1.6) in. (+1/8, -1/16) UNC 1/2* 26.99 1-1/16 9/16-12 5/8 30.16 1-3/16 5/8-11 3/4 31.75 1-1/4 3/4-10 1 42.86 1-11/16 1-8 *An L or is typically used to indicate minimum 12.70 mm (0.500 in.) diameter.
