1.1 这些规范涵盖了构成断电电力线路、供电站和设备上使用的临时接地系统的设备。 1.2 保护接地设备的用户通常会编制完整的说明和规定，以详细管理此类设备的正确使用和维护。 1.3 本设备的使用和维护不在本规范范围内。 1.4 使用铜缆的保护接地系统的这些规范分为四个部分，如下所示: 小节 临时保护接地夹具 4 – 16 临时保护接地用套管 17 – 30 临时保护接地电缆 31 – 39 保护接地（带夹具、套圈、，  和电缆） 40 – 52 1.5 这四个部分中的每一个都是其本身的一个实体，但为了完整性和澄清起见，将其列为系统的一部分。 1.6 电流显示在 表1 根据I.M.Onderdonk方程确定的电缆熔化时间，用于不对称值小于20%的情况( X/R ≤ 1.8). 看见 附录X1 . （A） 耐受和极限短路性能基于浪涌不超过20的性能 % 不对称系数（参见 9.1 和 12.3.4.2 ). （B） 屈服意味着没有永久变形，因此夹具不能在其整个应用范围内重复使用。 （C） 极限额定值表示组件或单个组件在规定时间内应承受的对称电流。 （D） 极限值基于将Onderdonk方程应用于规范允许的标称圆形密耳面积的98% B172型 和 B173 . 注1: TPG测试在完整组件上进行。装配额定值假设最低等级部件的等级（参见 43.1.6 ). 1.6.1 电流显示在 表2 基于EPRI项目RP2446计算机程序RTGC“用于计算临时接地电缆额定值的台式计算机程序”的值，并用于不对称值大于20%的情况( X/R ≧ 1.8），见 附录X2 . 注1: 上述电流值基于机电测试值。 注2: 经过这些处理的组件不得重复使用。 注3: 用于电流不对称系数超过20%的情况。 注4: 看见 X2.7.2 了解更多信息。 注5: 对于无法达到上述要求的实验室，可以使用替代测试电路。 看见 附录X2 详细信息。 注1: 表1 表示在此版本之前存在的夹具和组件额定值。 表2 表示高 X/R 情况。 1.6.2 看见 附录X1 和 附录X2 讨论这些主题。 1.7 以牛顿米为单位的数值应视为标准值。括号中的值为英寸-磅单位。 1.8 以下预防性警告与试验方法部分、章节有关 12 和 25 在这些规范中: 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

1.1 These specifications cover the equipment making up the temporary grounding system used on de-energized electric power lines, electric supply stations, and equipment. 1.2 It is common practice for the users of protective grounding equipment to prepare complete instructions and regulations to govern in detail the correct use and maintenance of such equipment. 1.3 The uses and maintenance of this equipment are beyond the scope of these specifications. 1.4 These specifications for a system of protective grounding utilizing copper cables are covered in four parts, as follows: Sections Clamps for Temporary Protective Grounds 4 – 16 Ferrules for Temporary Protective Grounds 17 – 30 Cables for Temporary Protective Grounds 31 – 39 Protective Grounds (Complete Assembly With Clamps, Ferrules,   and Cable) 40 – 52 1.5 Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification. 1.6 Currents presented in Table 1 are based upon cable melting times, as determined from equations by I. M. Onderdonk and are to used in situations involving an asymmetry value less than 20 % ( X/R ≤ 1.8). See Appendix X1 . (A) Withstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry factor (see 9.1 and 12.3.4.2 ). (B) Yield shall mean no permanent deformation such that the clamp cannot be reused throughout its entire range of application. (C) Ultimate rating represents a symmetrical current which the assembly or individual components shall carry for the specified time. (D) Ultimate values are based upon application of Onderdonk's equation to 98 % of nominal circular mil area allowed by Specifications B172 and B173 . Note 1: TPG testing is done on complete assemblies. Assembly ratings assume the grade of lowest graded component (see 43.1.6 ). 1.6.1 Currents presented in Table 2 are based upon the values from EPRI Project RP2446 Computer Program RTGC “A Desktop Computer Program for Calculating Rating of Temporary Grounding Cables” and are to be used in situations involving an asymmetry value greater then 20 % ( X/R ≧ 1.8), see Appendix X2 . Note 1: The above current values are based on electromechanical test values. Note 2: Assemblies that have been subjected to these shall not be re-used. Note 3: For use with currents exceeding 20 % asymmetry factor. Note 4: See X2.7.2 for additional information. Note 5: Alternate testing circuits are available for laboratories that cannot achieve the above requirements. See Appendix X2 for details. Note 1: Table 1 represents the clamp and assembly ratings that existed prior to this revision. Table 2 represents new ratings now required for high X/R situations. 1.6.2 See Appendix X1 and Appendix X2 for a discussion of these topics. 1.7 The values stated in Newton-Meter units are to be regarded as the standard. The values in parentheses are the inch-pound units. 1.8 The following precautionary caveat pertains to the test method portions, Sections 12 and 25 of these specifications: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.