天津市监控公司

First, the principle of elevator interference

1、电梯井内通常布置了动力、照明、风扇、控制、通信等线缆，各种电缆都会产生电磁辐射；假如使用同轴电缆传输，与天线接收原理相同，同轴电缆也会“接收”这些干扰，即干扰电磁场在电缆上产生干扰感应电流，这个干扰感应电流也就会在电缆外导体（编织网）纵向电阻上产生干扰感应电压（电动势），这个干扰感应电压刚好串联在视频信号传输回路“长长的地线”中，形成干扰；

1, elevator wells usually arranged power, lighting, fan, control and communication cables, cables will produce electromagnetic radiation; if using coaxial cable transmission and receiving antenna, the same principle, the coaxial cable will receive the interference, the interference of electromagnetic field interference induced current in cables, the interference of induction the current will conductors in the cable (net) interference induced voltage on longitudinal resistance (electromotive force), the interference induced voltage just in series of video signal transmission circuit of the long "ground", the formation of interference;

2、更重要的是这些随行电缆都是与视频电缆并行，且近距离捆扎在一起。这就形成了接近“最佳最有效的”干扰耦合关系。在一般工程中可以采用穿金属管或走金属槽的屏蔽干扰办法，但在电梯随动的环境中，这种方法无能为力。所以电梯环境下的抗干扰难度很大，只能选择较好的设计和施工方法；

2, more importantly, all the accompanying cables are in parallel with the video cable and are tied up in close range. This leads to the formation of the "best and most effective" interference coupling relationship. In general engineering, metal pipes or metal grooves can be used for shielding interference, but in the environment of the elevator, this method is powerless. Therefore, the anti-interference of the elevator environment is very difficult, so it can only choose better design and construction methods.

3、了解干扰产生基本原理，对完善抗干扰设计和施工十分重要。

3. It is very important to understand the basic principles of interference and to improve the design and construction of anti-interference.

二、电梯干扰的几种形式

Two. Several forms of elevator interference

1、横向条纹上下滚动

1. Rolling up and down the transverse stripe

这种现象表现为条纹不停的上或下滚动，条纹比较宽。看起来是干扰，其实并不是外界电磁波所为，如果抛开条纹，图像是清晰的。这种现象基本占所为图像干扰的80%以上，这种现象可以肯定的说是接地电位的问题，是指前端设备的地与中控室之间的地存在电位差，这个问题是万用表无法测试的，如果测得的数字是零，也并不代表它不存在电位差。唯一的办法是把它的回路给断开，也就是说两端的地断开一个(最好选择前端)。如果两端的地都不想断，怕影响防雷。那加个地隔离器来解决，这种设备为无源设备，只要串联在同轴电缆的任何一端，安装方便、效果好，完全可以消除这种条纹现象。

This phenomenon shows that the stripes are rolling up or down, and the stripes are wide. It seems to be a disturbance, but it's not the external electromagnetic wave. If the stripes are thrown away, the image is clear. This phenomenon is basically accounted for more than 80% of the image interference, this phenomenon can be sure that the ground potential problems, is refers to between the front-end equipment and control room of the potential difference, the problem is to test the multimeter, if the measured number is zero, it does not mean it has no potential difference. The only way to do it is to disconnect its loop, that is, to break one at the two ends (the best choice is the front end). If both ends of the ground do not want to break, fear of lightning protection. Add the ground isolator to solve the problem. This device is passive device. As long as it is connected to any end of the coaxial cable, it is easy to install and effective. It can eliminate the stripes.

2、网状干扰

2, network interference

这种现象图像质量很差，基本上看不到任何物体，图像时有时无，还有画面死机。这种现象是由于线缆的线芯和屏蔽断、短的缘故。这种情况大多数出现在接头上，个别也有在布线时没施工好。由于焊接的问题或接头件质量差引起的干扰在工程中也占多。

This phenomenon is very poor in image quality, basically invisible to any object, the image is sometimes no, and the picture is dead. This phenomenon is caused by the wire core and the shielding failure of the cable. Most of this is on the joint, and there is no construction in the wiring. The interference caused by the problem of welding or the poor quality of the joint is also a lot in the project.

3、空间电磁波的干扰

3, the interference of space electromagnetic wave

这种干扰源比较复杂，主要是前端设备、线缆中、终端附近有较强的辐射源或大功率的设备在运行。主要表现为图象扭曲、抖动等。所以在施工前应对周围的环境有所了解，尽量避开辐射源。在已经施工完了的工程中，而干扰有无法避免的情况下，只有加抗干扰设备。这种方法是比较经济、快捷、而图像又有保障。

The interference source is more complex, mainly in the front end equipment, cable, the terminal near the terminal has a strong radiation source or high power equipment in operation. The main manifestation is image distortion, jitter and so on. So we should understand the surrounding environment before construction, and try to avoid the radiation sources. In the project completed, and the interference can not be avoided, only the anti-interference equipment is added. This method is economical, fast, and the image is guaranteed.

三、双绞线传输电梯监控应用

Application of three, twisted pair transmission elevator monitoring and control

对井道内环境复杂，使用双绞线传输方式可以按照以下推荐的三种方案进行：

For the complex environment, the use of twisted pair transmission can be carried out according to the following three recommended schemes:

A)井道中部走线

A) moving line in the middle of the well

1、选择非屏蔽优质超五类线缆。

1, select unshielded high quality super five cable.

2、在井道中部的壁上开孔出线。

2. Opening the line on the wall of the middle of the well.

3、线缆随随行电缆捆扎，井道中部以下的线缆捆扎应作预留

3, the cable is tied with the cable, and the cable binding below the middle of the well should be reserved.

4、传输器根据距离要求选择，发射器应单独取电。

4. The transmitter is selected according to the distance requirement, and the transmitter should be taken separately.

B)电梯机房出线

B) lift off the line of the elevator

1、选择非屏蔽优质超五类线缆。

1, select unshielded high quality super five cable.

2、线缆随随行电缆捆扎，井道中部以下的线缆捆扎应作预留，井道上部线缆扎紧。

2, with the accompanying cable cable tie, well below the middle of the cable bundle should be reserved, the upper part of the shaft cable.

3、电梯机房内的线缆不宜走强电桥架，应及早与桥架分开连接至监控中心。

3, the cable of the elevator machine room is not suitable to walk the strong electric bridge, and should be connected to the monitoring center separately as early as the bridge.

4、传输器根据距离要求选择，发射器应单独取电。

4. The transmitter is selected according to the distance requirement, and the transmitter should be taken separately.

C)电梯机房安装

C) installation of elevator machine room

1、利用随行电缆自带的视频线作为前段介质，在电梯机房内安装发射器。

1. Using the video cable with the cable as the front medium, the launcher is installed in the elevator machine room.

2、传输器根据视频线长短选择无源或有源发射器。

2, the transmitter selects a passive or active transmitter according to the length of the video line.

3、接收器安装在监控中心，根据双绞线距离远近选择无源或有源接收器。

3, the receiver is installed in the monitoring center, and the passive or active receiver is selected according to the distance of the twisted pair line.

另外，传输器与电梯接地系统应分开进行。

In addition, the conveyors and elevator grounding systems should be carried out separately.

我们建议在监控中心将网线中剩余的线对接地，接收器接地是为保证设备免受过电压侵害。以上各种接地都采用独立的接地装置往往是很难实现的通常采用共用接地装置。一般要求共用接地装置的接地电阻不大于1Ω。接地线可采用一根截面积不小于16平方毫米的铜芯电线(PE线)首端与楼宇配电室内的PE线相连接，并可与电梯电源电缆同路敷设，接地线的末端与电梯机房内的辅助等电位板相连接。

We suggest that the remaining lines in the network line be butted in the monitoring center, and the receiver is grounded in order to ensure that the equipment is protected from overvoltage. The use of independent grounding devices for all kinds of grounding is often difficult to achieve by common grounding devices. The grounding resistance of the common grounding device is not more than 1 Omega. The grounding wire can use a copper core wire (PE line) with a section area of not less than 16 mm2, which is connected with the PE line of the building distribution room, and can be laid on the same road with the elevator power cable. The end of the grounding wire is connected with the auxiliary equipotential plate in the elevator room.

四、网线绑扎时注意以下几点

Four. Pay attention to the following points in the ligation of the net line

网线绑扎时注意以下几点：

The following points are paid attention to in the ligation of the net line:

1、选择合格偏柔软的非屏蔽网线。

1, select the qualified and soft unshielded net.

2、先用粗扎带在随行电缆上固定。

2. First use the roughing belt to fix on the cable.

3、用细扎带捆扎网线，固定在粗扎带里。

3. Tie the wire with a fine belt and fix it in the roughing belt.

4、粗扎带间距30厘米，网线每段预留3厘米。

4, the distance between the roughing belt is 30 centimeters, and the net line is reserved for 3 centimeters per segment.

五、双绞线布线注意问题

Five. Attention problems of twisted pair wiring

1、双绞线必须符合国家双绞线产品标准：

1, the twisted pair must conform to the standard of the national twisted pair product:

①、所用双绞线要为纯铜芯.线径为0.5毫米

1. The twisted pair is a pure copper core. The diameter of the wire is 0.5 millimeters.

②、单芯百米电阻为9.38欧姆，一箱线305米阻值在28欧姆左右，不要超过30欧姆

2. The single core 100 meter resistance is 9.38 ohm, one box line and 305 meters at about 28 ohms, not more than 30 ohms.

③、扭绞密度要

The twist, density