线电缆的定义及分类 Definition and classification of cable cables 广义的电线电缆亦简称为电缆。狭义的电缆是指绝缘电缆。它可定义为：由下列部分组成的集合体，一根或多根绝缘线芯，以及它们各自可能具有的包覆层，总保护层及外护层。电缆亦可有附加的没有绝缘的导体。 A broad wire cable is also referred to as a cable. A narrow cable is an insulated cable. It may be defined as: a set of consists of the following parts, a root or insulated wire core, and they may have a coating layer, the total protective layer and the outer sheath. Cables may also have additional conductors that have no insulation. 我国的电线电缆产品按其用途分成下列五大类： China's cable products are divided into five types: 1.裸电线； 1. The bare wire; 2.绕组线； 2. The winding line; 3.电力电缆； Power cables; 4.通信电缆和通信光缆； Communication cables and communications cables; 5.电气装备用电线电缆。 Electrical equipment USES wire and cable. 电线电缆的基本结构： Basic structure of wire cables: 1.导体：传导电流的物体,电线电缆的规格都以导体的截面表示。 Conductor: an object that conducts electricity, and the specifications of a wire cable are represented by the section of a conductor. 2.绝缘：外层绝缘材料按其耐受电压程度。 Insulation: the outer insulation material is subjected to its tolerance voltage. 工作电流及计算 Working current and calculation 电(线)缆工作电流计算公式： Electrical current calculation formula: 单相 Single phase I=P÷(U×cosΦ) I = P present (U * cos Φ) P-功率(W)；U-电压(220V)；cosΦ-功率因素(0.8)；I-相线电流(A)。 P - power (W); U-voltage (220V); Cos Φ - power factor (0.8); I - phase current (A). 三相 three-phase I=P÷(U×1.732×cosΦ) I = P present (U * 1.732 * cos Φ) P-功率(W)；U-电压(380V)；cosΦ-功率因素(0.8)；I-相线电流(A)。 P - power (W); U-voltage (380V); Cos Φ - power factor (0.8); I - phase current (A). 一般铜导线的安全截流量为5-8A/平方毫米，铝导线的安全截流量为3-5A/平方毫米。 The normal copper wire has a safe flow rate of 5-8a/sq mm, and the aluminum wire has a safe intercept of 3-5a/sq mm. 在单相220V线路中，每1KW功率的电流在4-5A左右，在三相负载平衡的三相电路中，每1KW功率的电流在2A左右。 In the single-phase 220V circuit, the current of every 1KW power is about 4-5a, and in the three-phase circuit of three-phase load balancing, the current of every 1KW is around 2A. 也就是说在单相电路中，每1平方毫米的铜导线可以承受1KW功率荷载；三相平衡电路可以承受2-2.5KW的功率。 That is, in a single-phase circuit, every square millimeter of copper wire can withstand 1KW power loads. A three-phase balancing circuit can withstand two to 2.5 KW power. 但是电缆的工作电流越大，每平方毫米能承受的安全电流就越小。 But the larger the work current of the cable, the smaller the safety current that can be borne by each square millimeter.