电缆的构造 The construction of cable 电缆按其构造及作用不同可分为电力电缆、控制电缆、电话电缆、射频同轴电缆、移动式软电缆等。 According to its structure and function, cables can be divided into power cables, control cables, telephone cables, radio frequency coaxial cables, mobile flexible cables, etc. 电缆的基本结构主要由三部分组成：导电线芯用于传输电能；绝缘层保证电能沿线芯传输，在电气上使线芯与外界隔离；保护层起保护密封作用，使绝缘层不被潮气浸入，不受外界损伤，保持绝缘性能。电缆结构如图10-10所示。 The basic structure of the cable is mainly composed of three parts: the conductive wire core is used to transmit electric energy; the insulation layer ensures the transmission of the electric energy along the core and isolating the core from the outside; the protective layer protects the seal from being immersed in the tidal gas without being damaged by the outside and keeps the edge performance. The cable structure is shown in Figure 10-10. 1.电缆按电压等级分类 1. cable is classified by voltage level 电力电缆一般是按一定电压等级制造的，电压等级依次为0.5kV、1、3、6、10、20、35、60、110、220、330kV。其中1kV电压等级电力电缆使用最多。3～35kV 电压等级的电力电缆在大中型建筑内主要供电线路常有采用。60～330kV 电压等级的电力电缆使用在不宜采用架空导线的送电线路以及过江、海底敷设等场合。按电压粗分可分为低压电缆(小于1kV)和高压电缆(大于1kV)。从施工技术要求、电缆接头、电缆终端头结构特征及运行维护等方面考虑，也分为低电压电力电缆、中电压电力电缆(1～10kV)、高电压电力电缆。 The power cables are generally manufactured according to a certain voltage level. The voltage levels are 0.5kV, 1, 3, 6, 10, 20, 35, 60, 110, 220, and 330kV respectively. Among them, the 1kV voltage grade power cable is the most used. 3 ~ 35kV voltage cables are often used in large and medium sized buildings. The 60 ~ 330kV voltage level power cables are used in the transmission lines that are not suitable for overhead conductors and for laying on the river and under the sea. The voltage can be divided into low voltage cables (less than 1kV) and high voltage cables (greater than 1kV). It is also divided into low voltage power cable, medium voltage power cable (1 ~ 10kV) and high voltage power cable from the aspects of construction technical requirements, cable joint, cable terminal head structure features and operation and maintenance. 2.电缆按电线芯截面积分类 2. classification of cable core section area 电力电缆的导电芯线是按照一定等级的标称截面积制造的，便于制造和设计与施工选型。我国电力电缆的标称截面积系列为2.5、4、6、10、16、25、35、50 、70、95、120、150、185、240、300、400、500、600mm2，共19种。 高压充油电缆标称截面积系列规格为100、240、400、600、700、845mm2共6种。多芯电缆都是以其中截面最大的相线为准。 The conductor core of the power cable is manufactured according to the nominal cross sectional area of a certain grade, which is convenient for manufacturing and design and construction selection. The nominal sectional area of power cables in our country is 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 185, 240, and 600mm2. The nominal sectional area of high voltage oil filled cables is 100, 240, 400, 600, 700 and 845mm2 6. Multi core cables are based on the maximum phase lines. 3.按导线芯数分类 3. classification by wire core number 电力电缆导电芯线有1～5芯5种。单芯电缆用于传送单相交流电、 直流电及特殊场合（高压电机引出线）。60kV及其以上电压等级的充油、充气高压电缆多为单芯。二芯电缆多用于传送单相交流电或直流电。三芯电缆用于三相交流电网中，广泛用于35kV以下的电缆线路。四芯电缆用于低压配电线路、中性点接地的TT方式和TN-C方式供电系统。五芯电缆用于低压配电线路、中性点接地的TN-S方式供电系统。二芯和四芯都是低压1kV以下的电缆。 The electric cable has 1~5 cores and 5 cores. Single core cable is used to transmit single-phase alternating current, direct current and special occasions (high voltage motor leads). Oil filled and inflatable high voltage cables with 60kV and above voltage levels are mostly single core. The two core cable is used to transmit single phase alternating current or direct current. The three core cable is used in three-phase AC network, and is widely used for cable lines less than 35kV. The four core cable is used for low-voltage distribution lines, neutral point grounding TT mode and TN-C mode power supply system. The five core cable is used for low voltage distribution line and neutral point grounding TN-S power supply system. The two core and four core are all cables under low pressure 1kV.