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电缆培训讲义一、概述（一）电缆的定义和分类用以传输电(磁)能、信息和实现电磁能转换的线材产品统称为电线电缆，广义的电线电缆亦简称为电缆，狭义的电缆指绝缘电缆。
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，以及它们各自组成可能具有的包覆层，总保护层及外护套层，电缆亦可以有附加的没有绝缘的导体。
按用途不同可以将电线电缆分为五大类：1、裸电线仅有导体而无绝缘层的产品，如钢芯铝绞线、铝绞线、铜绞线。
2、绕组线（电磁线）以绕组的形式在磁场中切割磁力线感应产生电流，或通以电流产生磁场作用的电线，如漆包线。
3、电力电缆在电力系统的主干线路中用以传输和分配大功率电能的电缆产品，如交联聚乙烯绝缘电力电缆等。
4、通信电缆和测量电缆及光缆传输电话、电报、电视、广播、传真、数据和其他电信信息的电缆产品。
5、电气装备电线电缆从电力系统的配电点把电能直接传送到各种用电设备、器具的电源连接线路用电线电缆，如控制电缆、布电线等。
（二）电线电缆的基本结构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。
2、绝缘将绝缘材料按其耐受电压程度的要求，以不同的厚度包复在导体外面而成。
3、保护层保护电缆的部分。
（三）电线电缆的的型号组成：类别或用途导体（一般省略）绝缘层（内）外层外护层如：YJV223×150mm2表示为铜导体交联聚乙烯绝缘聚氯乙烯护套钢带铠装电力电缆由三根导体截面为150mm2的电缆芯组成KVVP 7×1.5mm2 表示为铜导体聚氯乙烯绝缘铜丝编织屏蔽聚氯乙烯护套控制电缆由7根导体截面为1.5mm2的电缆芯组成DJYP2VP22×2×1.0mm2 表示为铜导体聚乙烯绝缘铜带绕包组屏蔽铜带绕包总屏蔽聚氯乙烯护套计算机电缆由2对2根导体截面为1.0mm2的电缆芯组成线对组成（四）常用电缆的型号字母的说明二、核级电缆（一）核级电缆的分类根据RCC-E的规定以电缆所处的环境条件可分为K1、K2、K3(质量鉴定级别) K1类电缆是在安全壳内使用的电缆K2类电缆是连接安全壳内和安全壳外使用的电缆K3类电缆是在安全壳外使用的电缆根据核级电缆使用的功能可分为：1、核级电力电缆2、核级控制电缆3、核级测量电缆(仪表电缆、补偿电缆)4、核级通信电缆（通信电缆、同轴电缆）（二）核级电缆的型号组成目前国际上没有核电站用核级电缆的通用标准或规范，并且中国国家电线电缆标准-关于核电站用核级电缆的相关标准和规范尚在编制过程中，并未发行公布。
电线电缆培训教材电线电缆分类电线电缆分为：1．电力电缆- - -传输电能2．通迅电缆- - -传输电信号3．电气装备用电缆- - -电气装备用的连接线4．光纤光缆- - -传输光信号一.电气装备用电缆AWM电子线---Appliance Wiring Material●电源线●电脑周边线1．常规电脑线2．音频线（AUDIO CABLE）3．视频线(VIDEO CABLE)4．USB电缆5．IEEE1394电缆6．SATA电缆二.通迅电缆系列●局域网络电缆- - -（LAN CABLE）●电话线- - -2C ,3C, 4C, 6C ,8C●同轴线STYLE NO.编号规则STYLE NO. 是按照电缆芯数(单芯或多芯)，绝缘及内外护套材料(热塑性，热固性)来进行编号的。
1- - -单芯线,热塑性绝缘2- - -多芯线,热塑性绝缘3- - -单芯线,热固性绝缘4- - -多芯线,热固性绝缘5- - -单芯或多芯,特种要求10- - -延续结构代号120- - -延续结构代号2STYLE PAGE中描述内容：每种结构对应一个代号(STYLE NO.)，在每个STYLE PAGE 中具体描述结构代号，电线名称，温度及电压等级，绝缘材料及厚度，导体材料及尺寸，有无屏蔽，燃烧性能要求，电缆线芯结构，外护层材料及厚度，电线的使用场合。
*为什么同一种线可以用不同的STYLE NO.？主要根据电线结构，使用场合，温度，电压等级等选择.安规方面产品认证●性能认证- - -通常性能认证的前提是获得安全认证，性能认证一般主要针对电气性能。
●安全认证- - -物理机械性能及燃烧性能等●印字内容- - -有些印字内容根据客户要求，如OEM类。
名词术语:导体：Conductor；绝缘：Insulation；芯线：Core；斜包：Spiral；对绞：Pair twist；编织：Braid；内护层：Inner jacket；外被：Jacket；填充：Filler；地线：Drain wire铝箔：Al-mylar；纸带：Paper tape；聚酯带：PET；外径：Outer Diameter裸铜：Bare Copper；镀锡铜：Tinned Copper；例：{（3C+S+IN）+1P+4C}+AL+D+B+Jacket OD=9.0mm电线电缆生产工艺一.下面以USB为例，分别介绍电线生产的工艺流程，生产设备●工序---导体绞合，绝缘押出，芯线对绞，成缆，编织，外被押出。
在我們深入討論CABLE MODEM之前﹐有必先和大家聊一聊寬帶網絡的概念。
從貝爾博士發明電話到1992年WWW因特網的流行﹐再到今天的寬帶網風云漸起﹐網絡的概念已經越來越多地出現在我們面前。
所謂寬帶﹐目前對筆者而言﹐超于傳統56KMODEM傳輸速率的都可以歸入寬帶的范圍。
眾所周知﹐電話的工作原理是將聲音信號轉換成電信號﹐借助電話線來傳送﹐然后在接收端將電信號再還原成原來的聲音信號。
在電腦發明之后﹐聰明的科學家于是想到了所謂DAC 數字模擬轉換器這種設備﹐如果把它加在電話機之前﹐先將數字信號轉成模擬信號﹐然后再利用電話線來傳送﹐最后再將模擬信號轉成數字信號不就可以完成數據傳送了嗎﹐于是MODEM也就應運而生。
從這個意義上分析﹐無論是目前廣泛應用的普通撥號連接的MODEM還是CABLE MODEM ﹐都不例外。
只不過傳統的MODEM使用的是雙絞線﹐而CABLE MODEM使用的則是同軸電纜。
話又說回來﹐盡管可以利用電話線來傳送信號﹐但電話線能承載的數據量比較小﹐那么為什么不用承載量比較大的線路來進行這種數據的傳輸呢﹖通過電力系統網絡顯然不太可能﹐因為那是用來傳送能量極大的電流﹐因此不易進行轉換。
那么接下來最可能實現這種傳輸的就應該算是有線電視網的線路了。
因此﹐在1993年初﹐美國的几個大型的調制解調器制造商開始研發CABLE MODEM﹐并且在1995年正是推出各種機型﹐而美國的有線電視業者當然也不會閑著﹐紛紛將機房內的設備升級成HFE網絡﹐而CABLE MODEM的用戶也越來越多﹐儼然成為寬帶接入因特網的主流連線設備之一。
Cable Modem 與ADSL Modem 之迷:在現在寬頻大戰的情況下, 在香港及台灣地區寬頻服務的收費比起一般撥號上網的確沒有相差多少. 很自然用家就會想用寬頻取代一般的撥號上網. 同時亦會問Cable Modem 這一類要共享的寬頻服務會否比ADSL Modem 來得慢嗎?其實這個問題根本就是沒有答案. 因為ADSL 寬頻所講的獨享其實是指由電話機樓(Central Office) 至用戶家中這一段以獨立電話線或光纖所連接的部份. 至於Cable Modem 方面又是如何呢? 以i-Cable 為例就是透過有線電視的HFC 光纖網絡系統由一個Fiber node 接點到多個用戶(Homepass). 由於是使用這種一對多點的傳送及廣播方式. 因此在同一區的用戶就會共享某一個特定的頻寬, 以i-Cable 為例就是38Mbps. 而ADSL 的賣點就在於不用共享, 但其速度一般比較低. 至於Cable Modem 則反之或者你會以為共享頻寬是以下列的數學方式計算:以頻寬為10Mbps 為例, 當十個用戶使用時每一個用戶所取得的頻寬為1Mbps. 而在有一百名用戶的情況下速度就會下降至100kbps. 但在實際運作的情況下不是如此, 因為Cable Modem 這一類有共享性的網絡都會有爆發Burst 的功能.這種特性令到用戶可以只在一段很短的時間內先行佔用全部的頻寬去完成一個傳送. 這種特性令在有大量用戶同時上網的情況下速度都不會有明顯的下降, 因為一般瀏覽網頁或者ICQ 只須要使用很少的頻寬. 除非在同一時間有大量的用戶一起下載一些大型檔案, 其速度的下降便會相當明顯.速度除了取決於用戶端之外, 更重要的是在於寬頻服務供應商在對外及對內頻寬跟用戶人數的比例. 如果用戶人數以倍數上升, 而對外則沒有相對地增加頻寬. 結果只會是不論Cable Modem 或者ADSL Modem 用戶速度都會相對下降.在理論上有線寬頻是可以透過加開頻譜以增加可供使用的頻寬或者是將Fibe node 所連接的用戶人數減少以達至加快速度的目的.CABLE MODEM的几個概念要了解CABLE MODEM 的原理﹐首先要對CABLE MODEM 的一些有所了解。
FABmaster 教育訓練教材iGerberFABmaster ASIA2003.12.22一．iGerber所需要之檔案iGerber Data Inputs and Outputs如上圖所示,iGerber軟體所需要之資料,可以分成下列幾種,1.Gerber Files<例>*%FSLAX23Y23*%*%MOIN*%G01*D12*X10382Y7902D02*X10429D01* Array Y7772D02*X10382D01*X10615Y7843D02*Y7890D01*Y10149D02*Y10197D01*X10429Y10209D02*Gerber File為CAD Layout軟體Design出一塊PCB板子後,附帶轉出之相關圖檔,主要用途在於可以將Gerber File繪出底片,再以底片為主製造出PCB板子出來。
Gerber Fie檔案內的內容主要為座標格式，依其格式可分為RS-274-D與RS-274-X兩種。
★RS-274-D :這種為較舊之Gerber File格式，因為每個座標均需要D-Code，故此種格式之D-Code需要另外一個檔案來說明D-Code，而那種檔案統稱為Aperture Files。
★RS-274-X :此為近年來才發展之格式，與RS-274-D最大之不同，在於它將Aperture Files整合在Gerber Files中，故檔案之種類較為單純，在Input 時較不易出錯。
2.Aperture Files<例>D11 ROUNDED 3.937 3.937 0.000 MULTI D12 ROUNDED 5.000 5.000 0.000 MULTI D13 ROUNDED 5.906 5.906 0.000 MULTI D14 ROUNDED 6.000 6.000 0.000 MULTI D15 ROUNDED 7.000 7.000 0.000 MULTI D16 ROUNDED 7.087 7.087 0.000 MULTID17 ROUNDED 7.333 7.333 0.000 MULTIGerber Files決定座標，而Aperture Files則決定形狀與大小。
Lesson ThirteenPower Cable (Ⅰ)In the power system, power cable and overhead conductor are all used in the energy transmission and distribution line. The construction cost of cable line is generally higher than that of overhead line, but in some particular cases, some projects, such as power transmission across large river or strait and direct introduction of super tension line into the center of city and industrial area, can only be fulfilled by using cable line, while it is not easy or completely impossible to fulfil these projects by overhead line. With the development of industry, the use of cable is increasing year by year in proportion to whole transmission line. The popularity of cable reflects not only the speed and depth of the development of power industry but also the degree of modernization of city construction. With the rapid development of national economy, the use of power cable is growing in popularity.When compared with the overhead line, the cable possesses the following features:1)It can be generally buried underground or installed indoors, in duct and tunnel, short distance between cables, without using the tower, taking up little space, without occupying space above ground.2)It is less effected by weather condition and surrounding environment. Stable transmission property and reliability.3)It can be developed toward super tension and large capacity on more favorable condition, such as cryogenic and super conductive cable.Therefore, the power cables are often used in urban underground network, leading-out line of power station, power supply within industrial and mining enterprises and underwater power transmission across the river and strait.The main construction elements of power cable are: conductor, insulation and sheath. The power cable should be provided with the shield, except 1-3 kV product. Various kinds of intermediate joints, terminations and the other accessories are also mounted in the cable line.The cable and its accessories should fulfil the following requirements:1)They can sustain long term operating voltage in the network and various overvoltage, such as operating overvoltage, atmospheric overvoltage and fault overvoltage, which frequently happen in operation.2)They can reliably transmit necessary power.3)They have good mechanical strength, bending property and anti-corrosion property.4)They have long service life.There are many kinds of power cable. The middle and low voltage cable (35kV and below): Mass-impregnated paper insulated cableNon-draining cablePVC insulated cablePE insulated cableXLPE insulated cableNatural rubber insulated cableEPR insulated cableHigh voltage cable (110 kV and above):Self-contained oil-filled cablePipe-type oil-filled cablePE insulated cableXLPE insulated cableIn the development of cable, it is the following important innovations in the construction, that made it possible for the cable to grow up from low voltage to high voltage. Firstly, in 1914, the shielded cable construction was put forward in Germany to improve the distribution of electric field inside cable. Secondly, in 1924, the construction of oil-filled cable was advanced in Italy. In this kind of construction, the insulating oil in cable and the oil tank were connected together to maintain the pressure in cable and remove the gas gap, in such case, the partial discharge in insulation was suppressed to enable the operating voltage of cable to rise to above 110 kV. Thirdly, since the seventies of the twentieth century, the extruded insulation cable has been developed to high voltage grade due to the application of triple extrusion and dry type crosslinking as well as the production of super clean insulation material.In 1958, our country began trial-producing the oil-filled cable. In 1964, the 66 kV oil-filled cable was made and put into operation at Dalian Second Power Plant, then the 110 kV, 220 kV and 330 kV oil-filled cables were manufactured one after another and used at Liu Jia Xia Power Station and so on. Finally, the high tension cables entered the city as the underground power transmission line. Developed in the early eighties of the twentieth century, the 500 kV oil-filled cable was used in Jin Zhou-Liao Yang 500 kV line for connecting the transformer and overhead line and approved by state authorities. In recent 10 years, there has been rapid development in the production of XLPE cable in our country and about twenty dry type XLPE crosslinking lines have been introduced from abroad, thus making possible the production of 220 kV XLPE cable.With the development of power industry, it is required of power cable, that its operating voltage will be getting higher and higher and the transmission capacity will be getting more and more. The highest operating voltage of power cable is 500 kV. The construction type of cable is as follows:Self-contained oil-filled cablePipe-type oil-filled cableXLPE insulated cableGas compression cableCryogenic cableSuperconductive cableThe wood fiber paper and PPLP paper are used as insulation of oil-filled cable, impregnated in synthetic oil (Dodecyl benzene). Now, the 500 kV XLPE insulated cable and gas compression cable are only used as leading-out line at power station. The trial production of 750 kV cable was carried on with success and the long term ageing test was qualified at 1100 kV voltage grade abroad.PPLP is the polypropylene and wood fiber laminated paper with the thickness ratio of polypropylene between 30%-50%. When used as insulation of super tension oil-filled cable, PPLP possesses the following advantage in comparison with wood fiber high voltage cable paper: low dielectric loss, high dielectric strength, stable thermal and mechanical properties, so it is a new and promising material. The voltage grade of PPLP insulated oil-filled cable has reached 500 kV, long term test has predicted its service life over 40 years.Lesson FourteenPower Cable (Ⅱ)Mass-impregnated paper insulated cableMass-impregnated paper insulated cable has been used nearly for a century. It is an important chapter of the development history of power cable. It undertook an arduous task of power transmission and distribution from low voltage to high voltage. The use of mass-impregnated paper insulated cable has the longest history and its consumption is the largest of all cables. It was famous for its advantage of having the long service life and high thermal stability. But, with the lapse of time and the continual appearance of original materials, its disadvantage, such as complicated manufacturing technology, long production cycle and large equipment investment, were thoroughly exposed, therefore it gradually faded out from the cable market in the voltage range below 35KV. Now, except a few state-owned cable factories, which used to produce a great number of paper insulated cables, continue to have its manufacturing equipment, some present leading cable factories, which have been established since the policy of reform and opening of our country to the outside world, have no such equipment at all.But, it should not be interpreted as a signal that the paper insulated cable has already been eliminated completely. Nor should it hastily conclude that such cable lost its use value long ago. It is still far too early to predict that such cable will soon quit the historical stage. Because in the high voltage area, such as 110KV, 220KV, 330KV, and much more 500KV, the paper insulated oil-filled cable still has a piece of land. Just in the middle of the nineties of last century, the Hong Kong China Light & Power Company, limited had installed a great number of paper insulated oil-filled cables at New Airport on the Lantao Island, a considerable part of them were supplied by mainland with good operation so far. At that time, the Hong Kong China Light & Power Company, Limited was faced with two alternatives, either to use the paper insulated oil-filled cable having good thermal stability, but complicated maintenance, or the XLPE insulated cable with mature technology and easy maintenance. After weighing the advantages and disadvantages, they finally made their decision to use the oil-filled cable. The action taken by such an authoritative power company, showed that it was a wise decision to use the oil-filled cable in the high voltage area, if in the light of stability. There is no doubt that oil-filled cable can certainly help a lot in the projects, such as large power station, dam and power transmission within big city. Even in the area below 35KV, despite the fact that the plastic extruded cable has already dominated the market, the paper insulated non-draining cable can still find favor in customers’eyes, because it is peculiarly suitable for use in vertical installation and tropical area.The mass-impregnated paper insulated cables can be divided into two types: common type and non-draining type (MIND). They are identical in their construction, but with different impregnants. They were popularly used at voltage of 35KV and below. The multiple–core cable with voltage of 10KV and below often shares a common metal sheath(lead or AL), it is so-called belted cable; for the cable with voltage of 20KV~35KV, if each insulated core has a lead (AL) sheath, it is so-called separated lead (AL) sheathed cable; if each insulated core is provided with a separate screen, but with a common metal(lead or AL) sheath, it is so-called individually screened cable.The common mass impregnant is a mixture of colophony and low voltage cable oil. The non-draining impregnant is often a mixture of low voltage cable oil and some plastics (such as polyethylene powder, polyisobutylene compound) as well as earth wax. The petroleum product or the synthetic oil are used as the low voltage cable oil.The common mass impregnant will flow even at low operating temperature. When the cable is installed at the position with high level difference, the impregnant will flow down from the top end, which results in drying up of paper insulation, decrease in insulation level and possible breakdown of insulation. At the same time, the impregnant continues to silt up at the lower end, which causes the expansion and cracking of lead sheath. The viscosity of common mass impregnant is decreasing, when temperature is increasing. The higher the temperature, the easier the impregnant flows. Therefore, its permissible working temperature is quite low as specified. The impregnant non-draining cable will not flow at its temperature of dropping point, so its permissible working temperature can be specified higher and the current capacity of cable can be increased.Lesson FifteenPower Cable (Ⅲ)Rubber insulated power cable (Ⅰ)The rubber insulated power cable is mainly used as connection cable in the power station, substation and within factory and enterprise. The cable is characterized by its outstanding softness and flexibility, so that it is peculiarly suitable for movable electric equipment.The rubber insulated power cable is suitable for use in fixedly installed power line at voltage of 6kV and below, which also can be regularly moved. When the cable is used in DC power system, its operating voltage can double the AC voltage.The rubber is an important material, which is popularly used in different departments of national economy. Because of its good physical and mechanical properties, high tensile strength and elongation, softness and flexibility, good electric insulating property, enough sealing property and different special properties of some kinds of rubber (such as oil resistance, solvent resistance, ozone resistance, high temperature resistance and flame retardant property), the rubber is popularized as insulation and sheath of different electric wires and cables with large consumption.1.1 Kind, usage and characteristics of rubberThe rubber is generally divided into two main types: natural rubber and synthetic rubber. The natural rubber is the first insulation and sheath material, used in electric wire and cable and continues to be used in great quantity. There is a rich assortment of synthetic rubbers, each has some special properties. With the rapid development of the petrochemical industry, the kind of rubbers, used in electric wire and cable and its consumption are growing. The kind, usage and characteristics of rubber, often used in cable industry, are separately introduced as follows.1. Natural rubber (NR)Largely thanks to its good properties, the NR enjoys the superiority over most of the synthetic rubbers in its tensile strength, elongation, softness and elasticity. Its comprehensive property, processability and thermal stability at 65℃and below are quite good, but it is inferior in its resistance to oil, solvent and atmospheric ageing; besides, it is a flammable material.The natural rubber is used as insulation material of different electric wires and cables at operating temperature at 65℃and below, and also as sheath material of indoor electric wires and cables free from oil and solvent. It is a wide-spread material, used in insulated and flexible wires as well as in general purpose rubber sheathed cables.2. Butadiene-styrene rubberThe butadiene-styrene rubber and the natural rubber bear the similarity in their properties, but the former is better in its heat resistance, while the latter is better in its mechanical property; therefore, both rubbers are often mixed together for use in the cable industry to reinforce the tensile strength and improve the thermal ageingproperty. The mixture of both rubbers is used in the same way as the pure natural rubber. When the butadine-styrene rubber is used alone, it can be used as insulation material with operating temperature of 75℃, it is also flammable.3. Polychloroprene rubber (PCP) or chloroprene rubber or neoprene rubber.Like the NR, the PCP has excellent mechanical properties. Due to the existence of chlorine atom, PCP is flame retardant, resistant to atmospheric ageing and ozone, it is resistant to oil and solvent to a certain extent, but its electric property is quite poor. It is mainly used as sheath material of shipboard, mining and outdoor electric wires and cables, also as insulation material of low voltage electric wires.4. Butyl rubberIts electric property and thermal ageing property are outstanding, the resistance to ozone, corona, chemical solvent and gas-tight property are also good, but its mechanical property and elasticity are low, it is flammable, not resistance to mineral oil and has poor processability (for example, it is not easy to be mixed and vulcanized). It can be modified by means of blending with polyethylene or halogenation. It is mainly used as insulation material of electric wire and cable at operating temperature of 80~85℃and 6kV above middle voltage shipboard cable, power cable and high voltage cable lead wire.5. Ethylene-propylene rubber (EPR or EPM) and Ethylene-propylene diene monomer (EPDM or EPT)The ethylene-propylene rubber (general name) has a slight advantage over the butyl rubber in properties and its processablity is much better, therefore, when high technical properties are required, it has a wide scope of application among electric wires and cables, for example, power cable, DC high voltage cable, motor lead wire, shipboard cable, 1kV mining cable and submarine cable. It is also a flammable material. It can be used as insulation and sheath.6. Nitrile-butadiene rubber (NBR)NBR has the advantage of being oil resistant, but not as good as expensive polysulfide rubbers, chloro-ether rubber and fluoro rubber. Its heat resistance is between EPR and butyl rubber. Its electric property is not so good, and it is also flammable. With the increase of propylene nitrile content in the rubber, its oil resistance, hardness and Gehman modulus are also improved, but its electric property, gas-tight property, chemicals resistance and cold resistance are worsened.It is mainly applicable for sheath material of electric wires and cables in direct contact with oil, such as oil and gas well wire and cable, motor lead wire and locomotive cable.The NBR and PVC compound, having the common characteristics of both materials, can improve NBR's oil resistance, ozone resistance, flame retardant property and electric property, therefore, it has found wide application in general insulated wire, flexible wire and motor lead wire.7. Chloro-ether rubberIt has excellent ozone resistance, oil resistance, cold resistance and thermal ageing property, but poor flexibility at low temperature, processability and highdensity. When its chlorine content reaches 37%-38%(CHR Type), it is flame retardant. It can be used as sheath material of submersible oil well pump cable and other oil resistant and high temperature cables.8. Chlorosulfonated Polyethylene rubber (CSP). Its trade name is Hypalon, produced by DuPont Co.CSP rubber is derived from polyethylene, it belongs to the rubber category because of having the characteristics of rubber material. When compared with PCP, CSP's electric property, resistance to atmospheric ageing, resistance to ozone, flame retardant property, thermal ageing property and resistance to chemicals are better, but the mechanical property is a little lower. It can be used as insulation of different high tension ignition wire and low voltage outdoor wire, and sheath of shipboard cable, mining cable, locomotive cable and lighting cable. If mixed with different rubbers, CSP can improve their ozone and weather resistant properties.9. Chlorinated Polyethylene (CPE)CPE rubber is also derived from Polyethylene, so CPE is similar to CSP in their characteristics. It has good atmospheric ageing resistance, ozone resistance, thermal ageing resistance, oil, chemicals resistance and flame retardance. CPE is used in the cable industry as popularly as CSP.10. Silicone rubber (SiR)SiR is the general name of polyorganosiloxane elastomer. It covers a wide range of properties, especially operating temperatures (-100 to +180℃) with the change of its composition. It is mainly used as insulation material of shipboard control cable, aircraft wire, H class motor leads and special power cable, such as fire-proof cable, also as covering of spaceship wire and cable.11. Fluoro rubberIn 1957, fluoro rubber, trade-named as VITON, was firstly put on the market by US DuPont Co. 26 type fluoro rubber is the most popular one of all fluoro rubbers. Fluoro rubber has the best thermal ageing resistance of all present rubbers, excellent oil, solvent resistance and good flame retardant property. It is mainly used as insulation and sheath of high temperature special wires.(to be continued)Lesson SixteenPower Cable (Ⅳ)Rubber insulated power cable (Ⅱ)Rubber is mainly employed as insulation and sheath material of electric wire and cable as well as filling, semi-conducting and repairing material, therefore, according to its usage, it can be divided into five types: insulation rubber, sheath rubber, filling rubber, semi-conducting rubber and repairing rubber. The main property requirements of different rubbers are briefly described as follows.1. Property requirements of insulation rubber1) Good and long-term stable electric insulation property. This is a basic property requirement. For the products with operating voltage 1kV and above, each has very high requirements of electric property. Such as D.C. high tension flexible cable requires high breakdown strength, high tension ignition wire requires definite surface insulation resistance and voltage-withstand ability. Some products (e.g. aircraft cable or sea geological detecting cable) require very high insulation resistance (25～100MΩ·km).2) Enough mechanical strength and definite flexibility and elasticity. Appropriate mechanical properties of rubber are requested for different kinds of electric wire and cable. The higher mechanical strength and flexibility are requested for the products, which are movable and frequently bended in use. The mining cable should be able to withstand definite impact, extrusion and tear force, applied by coal and rock. But, unlike the sheath rubber, such requirements may not be so important for the insulation rubber.3) Excellent thermal aging property. When used at different operating temperatures, the insulation rubber should keep excellent thermal aging property under the appropriate temperature condition and ensure good electric property at the maximum operating temperature.4) Good processability5) Other property requirements. When used in unsheathed cable, the insulation rubber should concurrently have the appropriate sheath's properties, such as resistance to weather ageing and oil, etc. When used in severe cold area (below -35℃), the insulation rubber should be cold resistant. The insulation rubber, used for high voltage cable, should be resistant to ozone ageing.2. Property requirement of sheath rubber1) Excellent mechanical property. Definite mechanical property are requested for rubber sheath, operating under different environmental conditions, such as it should withstand light outside force, pulling force and bending stress during installation of cable. Higher flexibility,elasticity and tensile strength are requested for the cable, which is movable in use. If used in mining cable and heavy duty rubber sheathed cable, which withstand frequently outside mechanical force, the sheath should have very high elasticity and resistance to tearing.2) Good weather ageing resistance. Sheath rubber should be able to work for a long time under the general atmospheric condition. Whether the sheath rubber has a good weather ageing resistance or not will directly affect the cable's service life. If the cable is used under special weather condition, the sheath rubber should have sun-light and freezing resistance.3) Thermal ageing property. Generally speaking, the thermal ageing property of sheath rubber can be lower than that of its compatible insulation rubber. But, when the operating temperature of cable is above 85℃, the thermal ageing property is also an important index for the sheath rubber.4) Different special protecting properties. Besides the above-mentioned basic requirements, there are also some special property requirements of sheath rubber for use under different environmental conditions. Such properties, e.g. oil resistance, flame retardance, fungus, mouse and termite resistance, are of vital importance to cable, used under these conditions.3. Property requirements of filling rubber.According to usage, there are two types of filling rubber. One is used to fill interspaces between multi-cores, when the cable is laying up. Not very good mechanical property and ageing resistance are required for this kind of rubber, therefore, low rubber content material or mixture of reclaimed rubber can be used. The other is also used to fill interspaces, besides, it functions as buffer layer between cores to withstand the impact of mechanical force. Enough elasticity and ageing resistance are required for such rubber. It should be made into a reasonable shape.4. Property requirement of semi-conducting rubber. Semi-conducting rubber is used as shielding layer of electric wire and cable. It is characterized by its semi-conducting property, the other properties are similar to insulation rubber. Its insulation resistance range differs according to the requirements in use. When the semi-conducting rubber is used to uniformize the electric field on insulation surface at 6kV and below, its volume resistivity should be about 103Ω*cm. When its function is to uniformize the electric field on the surface of conductor and insulation of H.V. cable, the volume resistance should be 105~107Ω*cm.The semi-conducting rubber should satisfy the requirement to have a stable and uniform insulation resistance. No conducting substance, decomposed out easily.5. Property requirement of repairing rubberThe property requirements of repairing rubber should be the same as for the insulation or sheath to be repaired. The repairing rubber is characterized by its ability to be cured at low or room temperature.( to be continued )Lesson SeventeenPower Cable (V)Rubber insulated power cable (III)Manufacturing process of rubber insulated power cable1. Rubber formulaOnly after a series of technological procedures together with relevant compounding ingredients, the caoutchouc will be turned into the rubber, having the operating properties, needed by the electric wire and cable. The rubber, used by electric wire and cable, is not the pure caoutchouc, but the rubber compound, based on the caoutchouc and processed together with relevant compounding ingredients through plasticizing, mixing and curing procedures. The rubber is named from the caoutchouc on which it is based.The rubber formula is comprised of such items: a kind of caoutchouc the rubber used, different kinds of relevant compounding ingredients and the quantity ratio between all these materials. Besides the properties of caoutchouc, which is used as basic material, the properties and quantity of compounding ingredients used have an important effect upon the properties of rubber, therefore, it is extremely important to reasonably choose the systems, kinds and quantity of compounding ingredients.The following systems can be divided based on the functions the compounding ingredients have in the rubber:1)Curing system. Being the high molecular material, having linear structure before heat vulcanization, the caoutchouc has a very high plasticity. Only after the linear structure is turned into the network structure with the addition of some elements, the caoutchouc has become elastic material with the other stable properties. Since the sulphur was firstly used in caoutchouc to accelerate the change from linear structure to network structure, this chemical reaction process is called "Sulphur vulcanization". The materials, used in the curing system, are a kind of important compounding ingredients, affecting the rubber's processability and the other properties.The materials, related to the vulcanization process of rubber, are: curing agent, curing accelerator and activator, used to increase the activation of above-mentioned two materials. The popular curing agents are sulphur (sulphur powder, sublimed sulphur and deposited sulphur), sulphureous compounds (JL-1, TMTD*) and peroxide (dicumin peroxide DCP); organic accelerator M; inorganic activator (zinc oxide, magnesium oxide) and organic activator(stearic acid).2)Protecting system. In the process of storage and normal use, the rubber will be gradually ageing. There are many reasons of ageing, but the most basic and unavoidable one is oxidation.Therefore, the existence of oxygen, especially ozone is a main factor in rubber ageing, while the existence of heat or some metal impurities (such as copper, manganese, iron) will accelerate the oxidation reaction of rubber. The function of materials used in protecting system is to prevent or retard the ageing process of rubber, caused by different factors.According to usage, the materials, used in the protecting system, can be divided into: antiager (including antioxidant, ozone inhibitor), anti-rat agent to eliminate rat pests, anti-ant agent to kill the termite and anti-fungus agent.3)Softening agent. The raw caoutchouc is a plastic material, but it is also a solid; consequently, during mixing different compounding ingredients, added in the caoutchouc, are not easily to be well-dispersed. The function of adding the softening agent is to adjust the caoutchouc's plasticity, improve its flexibility and also help the other compounding ingredients well mix with caoutchouc molecules. The softening agent also has its function to improve rubber's processability and the other properties.The transformer oil, industrial wax, pine tar oil and colophony are used as softening agents.4) Reinforcing-filling system. There are two kinds of compounding ingredients in this system. One is reinforcing agent, which can improve rubber's relevant physical and chemical properties, such as tensile strength, Gehman modulus, abrasion resistance, resistance to tearing and elasticity, when added in rubber. The other is filling agent, which can reduce the content of caoutchouc in the rubber, cheapen the cost and improve rubber's technological properties.A large number of reinforcing agents should be made up in the sheath rubber of electric wire and cable, the most popular one is carbon black, then the clay. There is no clear boundary line between the filling agent and reinforcing agent. The former helps little to the reinforcement of rubber, but it can increase the volume of rubber compound, reduce the cost, improve the technological properties and do no harm to rubber's properties. The popular filling agents, used in electric wire and cable, are: talc and light calcium carbonate.5)Special additive. Special additive is the material, which is added in the product according to the special requirement in use, such as colouring agent, which can make rubber coloured; flame retardant agent, which can make rubber not flammable or flame retardant; conducting agent, which can make rubber semi-conductive shield, etc.The rubbers, used for general electric wire and cable, are all flammable hydrocarbon. With the addition of flame retardant agent, the rubber becomes not flammable and the spreading of flames can be controlled. Containing the flame retardant element—chlorine, the polychloroprene rubber or chlorosulfonated polyethylene have good self-extinction property, but the appropriate flame retardant agent should still be made up in these rubbers in case high flame retardant property is required. The popular flame retardant agents for the rubber are halogen type, such as。
