Views:0 Author:Site Editor Publish Time: 2021-05-12 Origin:Site
The installation of cable lines should be carried out in accordance with the approved construction drawings.
The following inspections should be carried out before cable laying:
1. The technical documents of the product should be complete;
2. The cable type, specification and length should meet the design requirements, and the appearance is not damaged;
3. The cable end should be tight. When there are doubts about the visual inspection, the wet judgment or test shall be carried out;
4. If the cables are not installed immediately, they should be stored in a centralized manner, and low-halogen-free flame-retardant cables should be stored in a warehouse, not exposed to sunlight. The model, voltage, specification, and length should be marked on the disk. There should be a passage between the cable reels, and there should be no water in the cable storage.
5. Check the insulation quality before laying the cable.
The following conditions should be met before cable laying:
1. The civil engineering of the building related to the installation of cable lines is basically completed, and the quality of the project is in line with the relevant regulations in the current national construction and acceptance specifications for construction projects;
2. The wall hole between the dimmer room and the studio is reserved accurately and meets the design requirements. If there is a need for addenda, hole opening, or hole expansion, the civil works should be modified.
Cable pipe and cable tray laying
1. When the cable is laid with galvanized steel pipe, the line pipe should not have perforations, cracks, significant unevenness and serious corrosion, etc. The inner wall of the line pipe should be smooth and free of burrs. The cable conduit should not have cracks or significant dents after bending. Generally, the degree of flattening should not be greater than 10% of the outer diameter of the conduit, and the nozzle should be protected.
2. The bending radius of the cable conduit should meet the requirements of the bending radius of the cable worn. Each cable should have no more than 3 elbows, and no more than 2 right-angle bends. When indoor cables pass through walls and floors, they should be protected by steel pipes. The inner diameter of the steel pipe should not be less than 1.5 times the outer diameter of the cable.
3. The connection of metal line pipes should not be welded by mouth; galvanized steel pipes and steel pipes with a wall thickness of less than 2mm must not be pipe welded; when pipe joints with threaded connections are used, the joints should be well sealed.
4. When steel pipes are used as cable conduits, anti-corrosion paint should be applied to the surface; when galvanized pipes are used, anti-corrosion paint should be applied to the peeling part of the zinc layer.
5. The position of the cable conduit nozzle leading to the equipment should be convenient for connection with the equipment and does not hinder the disassembly, installation and access of the equipment. The nozzles of the cables and pipes laid side by side should be neatly arranged.
6. Where there are many or concentrated cables, cable trays should be used for cable laying. When cable trays (trays, ladders) are laid horizontally, the height from the ground should generally not be less than 2.5m. When laying vertically, metal cover plates should be added. protection.
7. When the cable tray is laid horizontally, the optimal span should be selected according to the load curve for support. Generally, the span should be 1.2m～2m. When laid vertically, the distance between the fixed points should not be greater than 2m.
8. When the cable tray is laid in multiple layers, the distance between the layers is generally: the control cable tray should not be less than 0.2m; the power cable (including the light cable) should not be less than 0.3m; the weak current cable tray and the power cable (including the light) Cable) The bridge should not be less than 0.5m, if there is a shielding cover, it can be reduced to 0.3m; the upper part of the bridge should not be less than 0.3m from the ceiling or other obstacles.
9. When several groups of cable trays are laid in parallel at the same height, the maintenance and repair distances between adjacent trays should be considered.
10. When the cable tray is parallel or crossed with various pipes, its small clear distance shall meet the requirements of Table 10.2.10.
Clear distance between cable tray and various pipes
11. The cable tray should not be laid above the heating pipeline, otherwise heat insulation measures should be taken.
12. The cable tray should be well grounded.
1. The phase wires and neutral wires of the same circuit should be laid in the same metal wire slot; the phase wires and neutral wires of the three-phase power supply should not pass through the inlet and outlet holes of the cabinet separately to avoid eddy current and interference.
2. Three-phase or single-phase AC single-core cables shall not be passed through the metal conduit alone; clamps and brackets used for fixing single-phase cables shall not form a closed ferromagnetic circuit.
3. The wires of different circuits, different voltage levels, and AC and DC should not be passed through the same conduit; the wires of the same AC circuit should be passed through the same metal conduit.
4. The cable channel should be unblocked, without water accumulation, and the metal parts should be intact.
5. The cable type, voltage and specifications should meet the design requirements. The appearance of the cable is not damaged and the insulation is good.
6. A spare length should be reserved near the end of the cable.
7. The small bending radius of the cable should comply with the regulations.
Cable small bending radius specification table
Note: 1 The data in brackets in the column of power cable refers to the small bending radius of the cable close to the connection box and the terminal. At this time, the bending of the cable should be carefully controlled, such as using a shaped guide plate. 2D is the outer diameter of the round cable, and H is the thickness of the flat ribbon cable.
8. When laying the cable, it should be led out from the upper end of the reel, and the cable should not be dragged by friction on the support and the ground, and the cable should not be twisted, or the protective layer should be broken or damaged.
9. When the cable is laid, the ambient temperature should not be lower than the stipulation in the table. When the temperature is lower than the stipulation in the table, corresponding measures should be taken.
Cables are allowed to lay low temperature standards
10. The lighting cables and control cables are laid by steel pipes or cable bridges from the dimmer room to the studio. Both ends of the steel pipes should be protected. After the cables are worn, fireproof materials should be used to seal them tightly.
11. In the dimmer room, cables should be laid in the raised floor or in the trenches with cable trays.
12. In the studio, the cables should be laid in the special cable tray for lighting.
13. When the cable is laid on the suspension device, it should be laid outside the telescopic device of the crane and vertical boom, or in the cable collecting plate or basket of the horizontal boom and self-lifting boom. The cable should not be affected by external forces. Tension and wear. The free hanging length of the flat cable intended for installation should not exceed 30 meters. When the use of the cable exceeds the above limit, the cable should be increased with tensioning measures.
14. Cables can be laid without spacing on the cable tray. The filling rate of the cross section of the cable in the tray: the filling rate of power cables (including light cables) should not be greater than 40%; the filling rate of control cables should not be greater than 50%.
15. The following cables with different voltages and different purposes are not suitable to be laid on the same layer of bridge: dual power cables with the same path to supply power to the first-class load; lighting cables and control cables. If restricted by conditions, when they need to be installed on the same bridge, they should be separated by partitions.
16. The cables in the cable tray should be fixed in the following places: when laying vertically, the upper end of the cable and every 1.5m～2m; when laying horizontally, the first and tail ends, turning and every 10m～15m of the cable .
17. The cables in the cable tray should be provided with numbers, models, starting and ending points and other signs at the beginning, end, turning and every 50m.
18. When cables and cable trays pass through firewalls and fire-proof floor slabs, fire isolation measures should be taken.
19. After the cable is laid, the debris should be removed in time and the cover should be covered.
20. Cables laid in cable trays and cable conduits should not have joints in the middle.
Cable terminal production
1. The length of the cable should be able to meet the requirements of laying and connection, and a margin of 5cm～10cm should be left at both ends of the wire. When the cable terminal is stripped and cut, the core and the remaining insulating layer should not be damaged. The cable terminal should be completely and firmly sealed with insulating tape or hot melt. The terminal should be clean and moisture-proof during the operation.
2. The light cable terminal should be made with permanent color mark. The mark should meet the requirements of the national standard "General Technical Requirements for Electronic Dimming Equipment" GB/T13582, and be consistent with the system phase. When installing a fixed dimming cabinet (box) system, both ends of the cable should be made with permanent marks that can easily identify the dimming circuit. The cable terminal from the power distribution cabinet to the dimming cabinet should also have a permanent color mark.
3. Light cables should use copper terminal blocks, and the specifications of the terminal blocks should be consistent with the cable diameter and fastener specifications. When stripping the end of the wire, the insulation layer should be stripped neatly, the core should be complete, and the length should be appropriate. The terminal is in close contact with the wire core and the wire skin. Use the special matching die tool to crimp the terminal and the wire head. If necessary, the connection can be soldered. The connection is beautiful and tight, and it is not easy to be pulled off by external force.
4. The manufacturing process of the control communication cable terminal should conform to the interface specification of the product.
Terminal fastening and connection
1. The terminal should be fastened to the terminal cabinet, sub-control box, dimming cabinet (box) or accessories with the specified screws, and the tightening torque should meet the relevant regulations. The screw specifications selected on site should meet the requirements of the national standard "General Technical Requirements for Electronic Dimming Equipment" GB/T13582.
2. When the cable is bundled and fixed, there should be a 5cm～10cm winding margin at the front end of each cable. When the terminal is loose, the cable must not touch other conductors.
3. The control cable should be reliably fixed near the connection end of the dimming cabinet (box) so that the control cable terminal will not be pulled by external force.