电缆.电流定额的计算.第3-3部分:运行条件的章节.横越外部热源的电缆

[中文适用范围]： IEC 60287的这一部分描述了一种计算涉及外部热源交叉的所有电压电缆的连续电流额定系数的方法。该方法适用于任何类型的电缆。该方法假设一根或多根电缆周围的整个区域具有均匀的热特性并且适用叠加原理。叠加原理并不严格适用于接触电缆，因此本标准规定的计算方法如果应用于接触电缆将产生乐观的结果。 [外文原描述]： Describes a method for calculating the continuous current rating factor for cables of all voltages where crossings of external heat sources are involved. The method is applicable to any type of cable. The method assumes that the entire region surrounding a cable, or cables, has uniform thermal characteristics and that the principle of superposition applies. The principle of superposition does not strictly apply to touching cables and hence the calculation method set out in this standard will produce an optimistic result if applied to touching cables