Requirements and Specifications for Installation of Cable Tray
The application of cable tray in our country is only more than ten years, in Europe and the United States developed countries but also a few decades. In a computer room project, compared with expensive, high-tech software and hardware, the bridge is not prominent, and it is not much concerned, but it is also an indispensable part of the entire wiring project. So, the construction of the installation of cable tray engineering requirements and specifications? Below together to understand the cable tray installation and construction requirements and specifications!
1.1 The general provisions apply to cables, bridge installation and cable laying in bridges for new and expanded general industrial and civil buildings with voltages below 10KV.
The installation of 1.2 cable tray and the laying of cables in the rack shall be carried out in accordance with the approved design documents.
1.3 the support, hanging, bracket support tray (slot) or step of the straight segment, non-linear bending combination, laying a continuous rigid structure system on the cable, as a cable tray.
1.4 metal cable trays and their supports and incoming or outgoing metal cable ducts must be grounded (PE) or grounded (PEN) and comply with the following regulations:
1.4.1 The full length of the metal cable bracket and bracket should be connected to the grounding (PE) or grounding) PEN) main line at more than 2 places.
1.4.2 The minimum allowable cross-sectional area of the copper core grounding wire and grounding wire at both ends of the connecting plate between non-galvanized cable trays is more than 4mm2;
1.4.3 The two ends of the connecting plate between the galvanized cable trays shall not cross the grounding wire, but the two ends of the connecting plate shall not be less than 2 connecting fixing bolts with locknuts or locknuts.
1.4.5 The laying of the cable shall not have defects such as twisting, crushing the sheath, cutting the protective layer, or causing serious damage to the surface.
1.4.6 When there are fire protection requirements for cable tray, fire isolation measures shall be taken.
2 Preparation for construction
2.1 technical preparation:
2.1.1 Technical and safety handover shall be carried out according to the approved construction organization design (construction scheme).
2.1.2 The technical standards, atlas and specifications for construction shall be complete.
2.1.3 Before laying the cable tray, check whether there is any place that cannot be constructed that crosses or overlaps with other equipment and pipelines. Before construction, negotiate with various types of work, supervision or construction companies and design companies to make records of smooth construction.
2.1.4 The calculation of cable traction should be carried out according to the construction drawing or the cable used in the construction.
1, cable tray specifications and models should meet the design requirements, accessories complete; bridge and accessories, accessories and fasteners of various steel should be galvanized standard parts.
2, all kinds of specifications of cable tray straight section, bending, rack accessories and branch, hanger column and section steel, etc. have product certificate, the inside and outside of the rack should be smooth and flat, no edges and corners thorn, no distortion, warping and other deformation.
3. The ordering or production of the bridge should be carried out in accordance with the design requirements, and there should be no errors, and the inspection should be repeated to avoid waste.
4. The installation of the bridge should choose to cut off the electrical interference of the cable circuit, there is corrosion, flammable dust should choose the place without cover closed tray, different areas need suitable place should choose the assembly tray or with hole tray and pedal frame; Dust and other need to cover the environment and outdoor places, preferably with a cover. When low-voltage power cables and control cables share the same tray or step, choose a tray or step with a partition in the middle; the branches of trays and ladder frames should be set with appropriate bends at the top and bottom; if due to space constraints, casual clothes are not bent or There are special requirements, you can choose soft connecting plates and hinge plates; set telescopic plates on telescopic slits; connect 2-level palettes and stepped frames with different widths or heights, plates of different widths or heights can be configured. But in the construction, the choice of support, hangers, bridge must be selected according to the design or engineering layout conditions.
5. The width and height of the tray and step are selected according to the following requirements:
1) The filling rate of cables into the rack should ensure that the power cables do not exceed 40%. Please control the control cable below 50%. In order to increase the cable in the future, to leave a certain spare space;
2) The carrying capacity of the selected tray and rack specifications shall comply with the regulations. The average load of the operation shall not be greater than the rated average load of the load level of the selected pallet and stepping rack.
3) The relative deflection under the average cloth load of the operation shall not be greater than 1/200.
The above is the cable tray installation and construction requirements and specifications, if you need to know more, you can contact us at any time!
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