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、測(cè)量定位：

1. Measurement and positioning:

用彈線法標(biāo)識(shí)橋架的安裝位置，確定好支架的固定位置，做好標(biāo)記。豎井內(nèi)橋架定位應(yīng)先用懸鋼絲法確定安裝基準(zhǔn)線，如預(yù)留洞不合適，應(yīng)及時(shí)調(diào)整，并做好修補(bǔ)。

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、電纜橋架制作安裝

2. Fabrication and installation of cable tray

我們依據(jù)施工圖設(shè)計(jì)標(biāo)高及橋架規(guī)格，進(jìn)行定位，然后依照測(cè)量尺寸制作支架，支架進(jìn)行工廠化生產(chǎn)。在無(wú)吊頂處沿梁底吊裝或靠墻支架安裝，在有吊頂處在吊頂內(nèi)吊裝或靠墻支架安裝。在無(wú)吊頂?shù)墓矆?chǎng)所結(jié)合結(jié)構(gòu)構(gòu)件并考慮建筑美觀及檢修方便，采用靠墻、柱支架安裝或屋架下弦構(gòu)件上安裝。靠墻安裝支架固定采用膨脹螺栓固定，支架間距不超過(guò)2米。在直線段和非直線段連接處、過(guò)建筑物變形縫處和彎曲半徑大于300mm的非直線段中部應(yīng)增設(shè)支吊架，支吊架安裝應(yīng)保證橋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、接地處理

3. Grounding treatment

電纜橋架的接地處理鍍鋅橋架之間可利用鍍鋅連接板作為跨接線，把橋架連成一體。在連接板兩端的兩只連接螺栓上加鍍鋅彈簧墊圈，橋架之間用不小于4mm2軟銅線進(jìn)行跨接，再將橋架與接地線相連，形成電氣通路。橋架整體與接地干線應(yīng)有不少于兩處的連接。

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、多層橋架安裝;分層橋架安裝

4. Multi layer bridge installation; Layered bridge installation

先安裝上層，后安裝下層，上、下層之間距離要留有余量，有利于后期電纜敷設(shè)和檢修。水平相鄰橋架凈距不宜小于50mm，層間距離應(yīng)根據(jù)橋架寬度小不小于150mm，與弱電電纜橋架距離不小于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.