电缆的屏蔽要求是根据不同场合分别采用:对绞组合屏蔽、对绞组成电缆的总屏蔽、对绞组合屏蔽后总屏蔽等方法。屏蔽材料有圆铜线,铜带、铝带/塑料复合带三种。屏蔽对与屏蔽对具有较好的绝缘性能,电缆在使用中若屏蔽对屏蔽对之间出现电位差时,不会影响信号的传输质量。
特种电缆就是有特殊用途、可以在特定场合使用的电缆,比如可以耐高温,耐酸碱,防白蚁,以及在轮船飞机核电站等场合使用的电线电缆。就分类来说,它与电力、控制、计算机电缆等类别不属于同一种分类方法,也就是上列电缆中也包含有特种电缆在内。一般特种电缆都需要制定企业内控标准。
特种电缆是一系列具有独特性能和特殊结构的产品,相对于量大面广的普通电线电缆而言,具有较高技术含量、较严格使用条件、批量较小、较高附加值的特点。往往采用新材料、新结构、新工艺和新的设计计算。
A类阻燃性能优于C类阻燃性能。使用特点额定电压U0/U为450/750V。电缆导体的长期允许工作温度为70℃。电缆的敷设温度不低于0℃。推荐的允许弯曲半径无铠装层的电缆,应不小于电缆外径的6倍。有铠装、铜带屏蔽结构的电缆,应不小于电缆外径的12倍。
矿用电力电缆具有以下列特性:(1)应能长期承受较高、甚至很高、极高的工作电压,电缆应具有非常优良的电气绝缘性能;(2)能传输很大的电流(几百甚至几千安培),为此电缆应有良好的热老化性(耐热性)和散热性;(3)电缆应有多种结构的护层以保护绝缘层,适应各种不同敷设环境(地下、水中、沟管隧道)的需要;(4。

Sheathed control cable insulation resistance: each conductor and the rest of the grounding wire core, control cable is more than 10000 m Ω. Km, more than 3000 m Ω HYAT cable. Km.
“电路改造”和“插座设置”是家装中非常重要的环节,对家装质量和今后的使用影响非常大,一定要好好把关,今天设计本就来为大家讲讲家庭电路改造中一些常见的偷工减料做法,还有插座设置要注意的事项,一起来学习吧。“裸线”埋墙按照规定,电线埋墙时,必须穿保护管。而往往有一些施工队,利用业主的信任与不了解,将电线不套穿线管直接埋入墙内。这是非常典型也是比较容易发现的偷工减料行为,这样做的后果是使得电线容易老化和破损,且无法换线,造成维修的难度加大N倍。
Precautions for installation of power cables: keep 2m distance when the cable is installed in parallel with the thermal pipe, and 0.5m should be maintained when crossing. The cable shall be installed at a distance of 0.5m in parallel or across other pipelines. When the cable is directly buried and installed, the direct buried depth of 1-35kv cable is less than 0.7m. When 10KV and below cables are installed in parallel, the net distance between them shall not be less than 0.1m and 10-35kv shall not be less than 0.25m. The distance of cross installation is not less than 0.5m. Cable laying temperature lower than 0 ℃, bending radius: multi-core cable or 15 (D + D), a single cable 20 or more (D + D), (D for cable diameter, D) for the conductor diameter. ? 6KV and above cable connector:? When installing the terminal head of the cable, the semiconductor electrical shielding layer must be stripped off. During operation, the insulation shall not be damaged. The shield end should be flat and the graphite layer (carbon particles) should be clean. (2) plastic cable end copper tape screened and armor must be good grounding, the short circuit also follow this principle, avoid unbalanced three-phase run ShiGang armoured end produce inductive electromotive force, and even "lighter" and sheath and other accidents. It is required to use my tinplate to braid copper wire for grounding lead. When connecting with the cable copper belt, it should be welded with chromium-iron tin. ? The shield of three-phase copper tape should be connected with ground wire respectively. Note that the shielded ground wire and steel armor ground wire should be separately drawn out and insulated from each other. The position of the welded ground wire should be as low as possible. Basic requirements for cable terminals and intermediate joints: a. good conductor connection; B. The insulation is reliable, and it is recommended to use irradiated cross-linked heat-shrinkable silicone rubber insulation materials; C. good sealing; D. sufficient mechanical strength to meet various operating conditions. The end of the cable must be used to prevent water and other corrosive materials from corroding, in order to prevent the water tree caused by the aging of the insulation layer and breakdown. Crane or forklift should be used for the loading and unloading of cables. It is forbidden to run flat or lay flat. For installation of large cables, cable laying cart should be used to avoid external damage or abrasion caused by manual dragging. If the cable cannot be laid in time for some reason, it should be stored in a dry place to prevent sunlight from exploding and water entering the end of the cable. ? Note: the installation of wire and cable should be familiar with the performance of wire and cable installation personnel or full-time technical personnel, if there are still unclear matters, ball related technical department or technical department of our factory.
航空航天、机车车辆、能源、钢铁、有色金属冶炼、石油开采、电机、建设等领域需用耐高温电线电缆。长期连续工作温度125度、135度、150度、180度、200度、250度及250度以上的耐高温电线电缆,常用的有辐照交联聚烯烃、硅橡胶、氟树脂、聚酰亚胺、云母、氧化镁等电线电缆。现介绍;两种新型耐高温电线电缆。MODBUS2X20AWG屏蔽双绞线
有强电与弱电之分,这里介绍一种强电用低感电缆。此电缆带有热耗散装置,用于各类接触焊机、电弧焊机与气动焊钳间相连接的新型水冷式低感电缆,具有结构简单合理、冷却水流通量大、不会形成堵塞阻断和限流现象、散热效果好、使用寿命长等特点。
3、矿用控制电缆产品型号规格及范围:矿用控制电缆型号规格范围使用场合MKVV,MKVVP,MKVVP20.5-10mm2,2-61芯适用于弱电控制系统或强电磁场干扰区MKVV22,MKVV200.5-10mm2,4-61芯MKVV32,MKVV300.5-10mm2,7-61芯MKVVR0.5-6m。

;MHYV矿用通信电缆、矿用通信电缆MHYA32矿用通信电缆、MHYAV矿用通信电缆、MHY32矿用通信电缆、MHYVR矿用通信电缆、MHYVP矿用通信电缆、MHYVRPMHYV1*2*0.5矿用通信电缆1*2*0.6矿用通信电缆1*2*0.7矿用通信电缆1*2*0.8MHYV1*4*0.5矿用通。
模块化编程实例我们使用AT89C52单片机,在编程软件keil环境下实施一个工程,来说明模块化编程具体操作的方法和步骤。例子要实现的功能:和P1相连的8个LED灯每500ms亮灭交替闪烁,通过串口将数字0-9发送给单片机并显示在一个数码管上。LED闪烁的时间使用定时器0中断方式来控制,T0每50ms溢出产生中断,定义一个计数器,每次T0中断就计数一次,累计计数10次,那么时长为500ms,作为LED闪烁时间间隔。
这种新型低感电缆也包括电缆和电缆端头上固装着的接头,且电缆也是由正极缆芯和负极缆芯同装于外胶管中构成。由于这类低感电缆一般都是用于电压为25-50V、电流在7000-12000A之间的场合,冷却水在电缆中的短路导电现象基本上可忽略不计,所以在此低感电缆中没有使用隔离正极缆芯和负极缆芯的橡胶软管,只是特别设置了一条横断面呈轮辐状(俗称“梅花芯”状)的芯架,其“轮心”和相邻“辐条”间所围成的空间在顺轴线方向上即形成纵向沟槽,芯架上的纵向沟槽与电缆所配置的正极缆芯的总根数相同,其电缆部分就是以正极缆芯和负极缆芯分别搁于芯架的纵向沟槽内装置在外胶管中构成。正极缆芯和负极缆芯的两端头部分别同极集合成束夹固于缆芯夹中,然后固装在接头上,电缆的外胶管的端头部套装在接头的尾端部,并用套装在外胶管外的收紧箍紧密封。
不得使用水、泡沫灭火器灭火。应该使用干黄沙和二氧化碳、干粉灭火器进行灭火。防止身体、手、足、或者使用的消防灭火器等直接与有电部分接触或有电部分过于接近造成触电事故。带电灭火时,还应该带绝缘橡胶手套。充油设备的灭火扑灭充油设备内部火灾时,应该注意以下几点:充油设备外部着火时,可用二氧化碳、121干粉等灭火器灭火;如果火势较大,应立即切断电源,用水灭火。如果是充油设备内部起火,应立即切断电源,灭火是使用喷雾水枪,必要时可用砂子、泥土等灭火。
4、绝缘:聚氯乙烯(PVC)、阻燃聚氯乙烯(ZR-PVC)、聚乙烯(PE)、阻燃聚乙烯(ZR-PE)、低烟无卤阻燃(WDZ)。可以采用任何一种方式敷设,更适用于岩石地区的直埋敷设。计算机信号电缆-DJYVP;DJYPV;DJYPVP;DJYJVRP;DJYPVP22。