With the rapid development of China's electric power industry, the use of cable tray has become more and more widely. Today, the editor will introduce the laying specifications of cable tray.
1. Cable tray wiring is suitable for places with large number or concentration of cables.
2. When cable tray is used for wiring in places with corrosion or special humidity, corresponding protective measures should be taken according to different corrosive media, and plastic sheathed cables should be selected.
3. When the cable tray is laid horizontally, the height from the ground should not be less than 2.5m, and when it is laid vertically, the height from the ground should not be less than 1.8m. In addition to laying inside and outside the special electrical room, when the requirements cannot be met, metal cover plate shall be added for protection.
Jinan cable bridge
4. When the cable tray is laid horizontally, the appropriate span should be selected for support according to the load curve, and the span should be 1.5-3m. When laying vertically, the distance between fixed points should not be larger than 2m.
5. When the cable tray is laid in multiple layers, the interlayer distance shall meet the following requirements:
(1) The distance between power cable trays shall not be less than 0.3m;
(2) The distance between telecommunication cable and power cable tray should not be less than 0.5m, and it can be reduced to 0.3m when there is shielding plate;
(3) The distance between control cable trays shall not be less than 0.2m;
(4) The distance between the upper part of bridge and obstacles such as ceiling, floor or beam should not be less than 0.3m.
6. When two or more groups of cable trays are laid in parallel at the same height or up and down, the maintenance and overhaul distance shall be reserved between adjacent cable trays.
7. The cable can be laid on the cable tray without space. The ratio of the total cross-sectional area of the cable to the cross-sectional area in the tray shall not be greater than 40% for the power cable and 50% for the control cable.
8. The cable tray should not be laid above the corrosive gas pipeline and heat pipeline and below the corrosive liquid pipeline. When the above requirements cannot be met, anti-corrosion and heat insulation measures shall be taken.
9. The cable tray should not be laid above the corrosive gas pipeline and heat pipeline and below the corrosive liquid pipeline. When the above requirements cannot be met, anti-corrosion and heat insulation measures shall be taken.
10. Cable trays shall not be connected through floors or walls.
11. When the length of straight section of steel cable tray exceeds 30m, or the length of aluminum alloy or glass fiber reinforced plastic cable tray exceeds 15m, expansion joints should be set. Compensation device shall be set at the place where the cable tray crosses the deformation joint of the building.