Long span bridge has the advantages of long service life, convenient equipment and low cost, simple maintenance and so on. But the preparation and wiring of long-span bridge is very precise and messy. Here are some considerations.

大跨距桥架作为布线工程的一个配套项目，现在尚无专门的规范阅历，各生产厂家的规范程式短少通用性，因此，规划选型进程应依据弱电各个系统缆显得类型、数量，合理选定适用的桥架;如与大跨距桥架合用时，应将电力电缆和弱电电缆各直一侧，选用隔板分隔;大跨距电缆与其它低电压电缆合用桥架时，应严格执行挑选具有外屏蔽层的弱电系统的弱电电缆，避免相互间的搅扰。总之,在规划、制作、设备、架起大跨距桥架时,有必要依据运用环境,因地制宜拟定可行性方案,选用相应方法,提巨大跨距桥架质量,以收到更好的效果。

As a supporting project of wiring engineering, there is no special specification experience for long-span cable tray, and the specification program of each manufacturer is short of generality. Therefore, the planning and selection process should reasonably select the suitable cable tray according to the type and quantity of each weak current system cable; If it is used with long-span bridge, the power cable and weak current cable should be separated on each straight side, and the center should be separated by partition; When long span cables and other low voltage cables share the same bridge, the selection of weak current cables with external shielding layer of weak current system shall be strictly implemented to avoid mutual interference. In a word, when planning, making, equipping and erecting large span bridge, it is necessary to draw up feasible scheme according to the application environment and local conditions, select corresponding methods, and improve the quality of large span bridge, so as to receive better effect.

大跨距桥架起备注意事项：

Precautions for large span bridge operation:

1、桥架高度：高度为50、100时每端各6只联接孔，高度为150、200时每端各12只联接孔。

1. Bridge height: when the height is 50 and 100, there are 6 connecting holes at each end, and when the height is 150 and 200, there are 12 connecting holes at each end.

2、支撑距离：支撑距离应小于等于载荷曲线容许载荷和支撑跨距。

2. Support distance: the support distance shall be less than or equal to the allowable load of load curve and support span.

3、桥架宽度：挑选电缆桥架的宽度时，应留有必定的备用空位，以便为往后增加电缆用。

3. Bridge width: when selecting the width of the cable bridge, there should be a certain spare space for the future increase of cable.

4、离隔敷设：当电力电缆和控制电缆较少时，可以在同一电缆桥架起备，但须用隔板将电力电缆和控制电缆离隔敷设。

4. Separated laying: when there are few power cables and control cables, they can be prepared in the same cable tray, but the power cables and control cables must be separated by a partition in the center.

5、电缆固定：汇线桥架水平敷设时，桥架之间的联接应尽量设置在跨距1/4处。水平走向的电缆每隔2米左右固定一下，笔直走向的电缆每隔1.5米左右固定一下。

5. Cable fixation: when the cable tray is laid horizontally, the connection between the cable trays should be set at 1 / 4 of the span as far as possible. The horizontal cable should be fixed every 2 meters or so, and the straight cable should be fixed every 1.5 meters or so.

大跨距桥架布线注意事项：

Precautions for large span cable tray wiring:

1、如果设备场所为具有腐蚀性或者是非常湿润的环境，那么在布线时就有必要要依据腐蚀介质的不同来选用相应的防护方法。

1. If the equipment site is corrosive or very humid environment, then it is necessary to choose the corresponding protection method according to the different corrosive medium when wiring.

2、若是将几组电缆桥架一同在同一高度进行平整设备的时分，就需要考虑各组电缆桥架之间的维护和检修距离。

2. If several groups of cable trays are leveled at the same height, the maintenance and overhaul distance between each group of cable trays should be considered.

3、在大跨距电缆桥架上时可以进行无距离敷设电缆的，电力电缆在桥架内的横断面填充率要在40%以下，而控制电缆则应小于桥架横断面积的一半。

3. If the cable can be laid without distance on the long span cable tray, the filling rate of the power cable in the cross section of the tray should be less than 40%, while the control cable should be less than half of the cross section area of the tray.

4、设备大跨距电缆桥架的时分不能设备在具有腐蚀性气体管道以及热力管道的上方，在腐蚀性液体管道的下方也不能直接设备电缆桥架，若是有必要如此的话则应做好防护和隔热方法。

4. When the equipment has a long span cable tray, the equipment shall not be placed above the corrosive gas pipeline and thermal pipeline, or directly under the corrosive liquid pipeline. If necessary, the protection and heat insulation methods shall be taken.

大跨距桥架的设备布线是非常精密和杂乱的一项作业，如果在设备布线进程中呈现失误就可能对往后的运用构成很大的问题，所以缔造大跨距桥架进程中，必定要注意施工。

The equipment wiring of long-span bridge is a very precise and messy operation. If there are mistakes in the process of equipment wiring, it may pose a great safety problem for the future application. Therefore, in the process of creating long-span bridge, we must pay attention to the construction safety.