Type selection design of cable tray: strong and weak current lines shall be laid in separate slots. When strong and weak current intersect in junction boxes (boxes), metal separation plates must be used to separate them. Strong and weak current conductors shall not be directly contacted in the slot. Various wiring in the ground trunking can only be connected at the outlet of the junction box. During the construction and installation of ground trunking, all trunking pipes are required to be connected into a reliable grounding whole.

1、测量定位：

1. Measurement and positioning:

用弹线法标识桥架的安装位置，确定好支架的固定位置，做好标记。竖井内桥架定位应先用悬钢丝法确定安装基准线，如预留洞不合适，应及时调整，并做好修补。

Mark the installation position of the bridge with the snap line method, determine the fixed position of the support and mark it. The installation datum line shall be determined by the hanging steel wire method for the positioning of the bridge in the shaft. If the reserved hole is inappropriate, it shall be adjusted in time and repaired.

2、电缆桥架制作安装

2. Fabrication and installation of cable tray

我们依据施工图设计标高及桥架规格，进行定位，然后依照测量尺寸制作支架，支架进行工厂化生产。在无吊顶处沿梁底吊装或靠墙支架安装，在有吊顶处在吊顶内吊装或靠墙支架安装。在无吊顶的公共场所结合结构构件并考虑建筑美观及检修方便，采用靠墙、柱支架安装或屋架下弦构件上安装。靠墙安装支架固定采用膨胀螺栓固定，支架间距不超过2米。在直线段和非直线段连接处、过建筑物变形缝处和弯曲半径大于300mm的非直线段中部应增设支吊架，支吊架安装应保证桥架水平度或垂直度符合要求。

We locate according to the design elevation of the construction drawing and the specification of the bridge, and then make the support according to the measured size for industrialized production. Where there is no ceiling, it shall be hoisted along the beam bottom or installed by the wall support, and where there is ceiling, it shall be hoisted in the ceiling or installed by the wall support. In public places without suspended ceiling, combined with structural components and considering the beauty of the building and convenient maintenance, it shall be installed against the wall, column support or on the lower chord components of roof truss. The support installed against the wall shall be fixed with expansion bolts, and the spacing between supports shall not exceed 2m. Supports and hangers shall be added at the connection of linear section and non-linear section, at the deformation joint of building and in the middle of non-linear section with bending radius greater than 300mm. The installation of supports and hangers shall ensure that the levelness or verticality of bridge meets the requirements.

3、接地处理

3. Grounding treatment

电缆桥架的接地处理镀锌桥架之间可利用镀锌连接板作为跨接线，把桥架连成一体。在连接板两端的两只连接螺栓上加镀锌弹簧垫圈，桥架之间用不小于4mm2软铜线进行跨接，再将桥架与接地线相连，形成电气通路。桥架整体与接地干线应有不少于两处的连接。

The grounding treatment of cable tray can use galvanized connecting plate as jumper between galvanized trays to connect the trays into one. Galvanized spring washers shall be added to the two connecting bolts at both ends of the connecting plate. The bridge shall be bridged with soft copper wire of no less than 4mm2, and then the bridge shall be connected with the grounding wire to form an electrical path. There shall be at least two connections between the whole bridge and the grounding main line.

4、多层桥架安装;分层桥架安装

4. Multi layer bridge installation; Layered bridge installation

先安装上层，后安装下层，上、下层之间距离要留有余量，有利于后期电缆敷设和检修。水平相邻桥架净距不宜小于50mm，层间距离应根据桥架宽度小不小于150mm，与弱电电缆桥架距离不小于0.5m。

Install the upper layer first and then the lower layer. The distance between the upper and lower layers shall be reserved to facilitate cable laying and maintenance in the later stage. The clear distance between horizontal adjacent bridges shall not be less than 50mm, the distance between layers shall not be less than 150mm according to the bridge width, and the distance from weak current cable bridge shall not be less than 0.5m.