1. In engineering design, the layout of cable tray should be comprehensively compared according to economic rationality, technical feasibility, operation safety and other factors to determine the best scheme, and fully meet the requirements of construction, installation, maintenance and cable laying.
2. When laying the cable tray horizontally, the height from the ground shall not be less than 2.5m. When laying the cable tray vertically, the part below 1.8m from the ground shall be protected by metal cover, except when laying in special electrical rooms. If the cable tray is laid horizontally on the equipment interlayer or on the horse path below 2.5m, protective grounding measures shall be taken.
3. The cable tray, cable groove and its support and hanger should be made of corrosion resistant rigid materials when used in corrosive environment. 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. Cable tray in the section with fire requirements, can be added in the cable ladder, tray with fire-resistant or refractory board, mesh and other materials to form a closed or semi-closed structure, and take measures on the bridge and its support hangers coated with fire coating. Its overall fire resistance performance should meet the requirements of 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.
7. Cables of different voltages and USES should not be laid in the same layer of cable tray:
(1) cables above 1kV and below 1kV:
(2) double-loop cables that supply power to the first-level load with the same path;
(3) cables for emergency lighting and other lighting:
(4) power, control and telecommunication cables.
If different grades of cables are laid on the same cable tray, partitions should be added in the middle.