1. In the engineering design, the layout of the bridge shall be comprehensively compared according to economic rationality, technical feasibility, operation integrity and other factors to determine the * scheme, and fully meet the requirements of construction installation, maintenance and repair, and cable laying.
2. When laying the bridge horizontally, the height from the ground shall not be less than 2.5m. When laying vertically, the part below 1.8m from the ground shall be protected by metal cover, except when laying in special electrical rooms. The cable tray is laid horizontally on the equipment sandwich or horse path and below 2. 5m. Protective grounding measures shall be taken.
3. the bridge, the line groove and its support and hanger are used in corrosive environment, shall be made of corrosion resistant rigid materials. Or take anti-corrosion treatment, anti-corrosion treatment should meet the requirements of engineering environment and durability. Aluminum alloy cable tray should be used in places with high corrosion resistance or clean requirements.
4. the bridge frame in the section with fire requirements, can be added in the cable ladder frame, tray with fire-resistant or fire-resistant performance of the board, mesh and other materials to form a closed or semi-closed structure, and take the bridge and its support hanger surface coating brush fire protection measures. Its overall fire resistance shall meet the requirements of the relevant national codes or standards. In engineering fire protection requirements of higher places. Aluminum alloy cable tray is not suitable.
5. Cable lines that need to be shielded from electromagnetic interference. Or protection from external shadows such as outdoor sunlight, oil, corrosive liquids, flammable dust and other environmental requirements. Non - hole tray cable tray should be used.
6. In places prone to dust accumulation, the cable tray should use cover plate; Cross road segments at public access or outside. Bottom bridge should be added to the plate or the use of non - porous tray.