1.1 本规范涵盖了由圆形铜线制成的裸组合单面绞合导线，其未涂覆或涂有锡或铅合金，用于电气用途的绝缘导线。这些导线应由两层螺旋敷设的导线包围的中心芯线构成，其外径等于压缩绞合等效导线。（见说明 注1 和 注释2 .) 注1: 在本规范中，组合unilay导线的定义如下:一根中心芯线，由一层六根直径与芯线相同的螺旋敷设导线包围，外层螺旋敷设，其中六根较小的导线在六根直径与下面一层导线相同的导线之间交替排列。两层都有一个共同的铺层长度和方向（参见 图1 ). 图1 导线横截面 1.2 就本规范而言，普通导线分类（AA、A、B、C类）不适用，因为这些导线用于后续绝缘。 应使用描述性术语组合unilay绞合代替导线分类。 1.3 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.3.1 对于AWG或kcmil指定的导线尺寸，以国际单位制表示的要求已从以英寸-磅单位表示或推导的相应值进行数字转换。 1.3.2 对于仅由国际单位制指定的导线尺寸，要求以国际单位制表示或推导。 1.3.3 对于密度、电阻率和温度，以国际单位制表示的值应视为标准值。 1.4 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。 1.5 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 This specification covers bare combination unilay-stranded conductors made from round copper wires, either uncoated or coated with tin or lead alloy for insulated conductors for electrical purposes. These conductors shall be constructed with a central core wire surrounded by two layers of helically laid wires, resulting in an outer diameter equal to the compressed-stranded equivalent conductor. (See Explanatory Note 1 and Note 2 .) Note 1: For the purpose of this specification, combination unilay conductor is defined as follows: a central core wire surrounded by a layer of six helically laid wires of the same diameter as the core wire with a helically laid outer layer containing six smaller wires alternated between six wires of the same diameter as the wires in the layer underneath. Both layers have a common length and direction of lay (see Fig. 1 ). FIG. 1 Cross Section of Conductor 1.2 For the purpose of this specification, normal conductor classification (Class AA, A, B, C) is not applicable as these conductors are intended for subsequent insulation. The descriptive term combination unilay-stranded shall be used in place of conductor classification. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.3.1 For conductor sizes designated by AWG or kcmil, the requirements in SI units have been numerically converted from corresponding values, stated or derived, in inch-pound units. 1.3.2 For conductor sizes designated by SI units only, the requirements are stated or derived in SI units. 1.3.3 For density, resistivity, and temperature, the values stated in SI units are to be regarded as standard. 1.4 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. 1.5 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.