When the cable is laid vertically in the cable tray, it should be fixed on the tray support at the upper end of the cable every 1.5m; when it is laid horizontally, it should be fixed at the head end, end and corner of the cable and every 5~ 10m.
When laying cables in horizontal and vertical bridges and vertical trunking, the cables shall be bundled. Stranded cables, optical cables and other signal cables shall be bundled according to category, quantity, cable diameter and number of cable cores. The binding spacing shall not be greater than 1.5m, and the spacing shall be even and moderately elastic.
The optical cable in the building should be laid in the metal trunking, and when the bridge is laid, a cushion cover should be installed at the binding and fixing place. When cables are laid in the ceiling by using the support columns of the ceiling as trunking, the cables within the jurisdiction of each support column need not be laid with trunking, but should be laid in bundles, the cable sheath should be flame retardant, and the cable selection should meet the design requirements.
The technical requirements for the construction of power, optical cable overhead, pipeline, direct burial, wall penetration and underground pipe laying in the subsystem of the building complex shall be implemented in accordance with the relevant provisions of the acceptance of the local network communication line project. protection measures
Cable laying protection of horizontal subsystem shall meet the following requirements. The protection requirements for embedded concealed pipes are as follows:
(1) The maximum pipe diameter embedded in the middle of the wall shall not exceed 50mm, and the maximum pipe diameter of the concealed pipe in the floor shall not exceed 25 mm.
(2) A wire box device shall be set every 30m for straight pipeline laying.
(3) The turning angle of concealed pipes should be greater than 90 degrees, and the turning angle of each concealed pipe on the path should not be greater than 2 degrees, and there should be no S-bend. When the length of the elbow section exceeds 20m, a pipeline box device shall be set; When there are two bends, the set length of the box shall not exceed 15m.
(4) The radius of curvature of concealed pipe turning should not be less than 6 times of the outside diameter of the pipe. If the outer diameter of the concealed pipe is greater than 50mm, it should not be less than 10 times.
(5) The nozzle of the concealed pipe should be smooth and protected by mouth protection, and the protruding part of the nozzle should be 25 ~ 50 mm ... The protection requirements for cable laying on the network floor are as follows: (1) There should be communication between trunking. (2) The trough cover plate shall be openable.
(3) The width of the main line slot depends on the width of the network floor, generally about 200mm, and the width of the branch line slot should not be less than 70 mm ..
(4) The floor should be compressive, impact-resistant and flame-retardant. The spacing of fixed points at the bottom of plastic trunking is generally1m.
When laying the raised floor and laying cables, the clearance in the raised floor should be 150~300mm. When public columns are used as ceiling support columns, cables can be laid in the columns. Pillar support points should avoid the position of grooves and trunking, and the support should be firm. When the power cord in the column and the integrated wiring cable are laid together, there should be a metal plate in the middle, and the spacing should meet the design requirements.
The cable laying protection mode of trunk subsystem shall meet the following requirements:
Cables shall not be laid in elevators or shafts of water supply, steam supply and heating pipelines, nor shall they be laid in high-voltage shafts. There should be communication between trunk channels. 2. Trunk subsystem
The relay subsystem is used for transmission between buildings, and generally uses multiple pairs of twisted pair or multimode optical fiber. Optical fiber has strong anti-interference ability, and there will be no problems such as twisted pair after installation. However, the optical fiber itself is fragile, and strong pulling or bending will cause the core to break, so experienced engineers should be on site to guide the installation. The erection of optical fiber can be carried out by overhead, direct burial, pipeline, etc. Warning signs should be made where the optical fiber passes during direct burial to prevent damage in future construction.
Because the fiber core of optical fiber is easily broken by timely glass, it is absolutely not allowed to exceed the allowable minimum bending radius during construction. At least 10 times the outer diameter of the optical fiber when it is bundled; When pulling the cable, it should be at least 15 times of the outer diameter of the optical fiber. Secondly, the tensile strength of optical fiber is smaller than that of copper cable, so it must not exceed the tensile strength (46N) during construction. Optical fiber distribution frames can be divided into wall-mounted and rack-mounted types. According to the number of terminated optical fibers, it can be divided into 24 ports, 48 ports and 72 ports. There is an adapter plate on the distribution frame for installing couplers. Optical fibers should be properly bundled before entering the distribution frame, and some spare cables should be reserved after entering the distribution frame for installation and maintenance. The standby cable shall be wound on the reel of the optical fiber distribution frame. 3. Manage regional subsystems
Management area subsystem is the most complicated part in engineering construction. This part of the construction should fully consider the environmental impact and the impact of the termination process.
Electromagnetic radiation is the main factor to consider the installation environment of subsystem in management area. The influence of electromagnetic radiation mainly comes from two aspects, one is the influence of environment on system transmission, and the other is the influence of system on environmental equipment during information transmission. In buildings, the influence of environment on system transmission mainly comes from strong electromagnetic radiation sources, such as radio stations, elevators, motors, UPS power supplies and so on. If these interference sources have great influence in the environment, shielding measures should be considered, or remote locations should be selected.
The termination process of wiring system is an important factor that directly affects the system performance. The installation process of connecting hardware mainly affects the near-end crosstalk and attenuation of wiring system, and these two parameters are an important basis for judging the performance of the system. In the management area subsystem, the ventilation, lighting, pH, humidity and other conditions of the environment should also be considered. These factors will cause corrosion and aging of terminal fittings, which will affect the performance of the system for a long time. The safety of the management area subsystem should also be considered, and the terminal fittings should be installed in the wiring cabinet or wall cabinet. 4. Workspace subsystem
There are many factors to be considered in the construction of workspace subsystem, because different room environments need different information wall seats to cooperate with them. In architectural design, users' demand for indoor layout should be considered as much as possible, and the convenience and safety of connecting application equipment (such as computers, telephones, etc.) should also be considered. ) from the information wall seat.
Wall-mounted information wall seats generally consider embedded installation. The standard 86-type wall box is adopted in China, which is square, with specifications of 80 ×80mm and screw hole spacing of 60 mm ... The distance between the information wall box and the power wall seat should be greater than 20 cm. Desktop wall seat should be coordinated with furniture and desk, and the safety of installation location should be considered. The distance between the information wall box and the power wall seat should be more than 20 cm.
The movable floor is installed in a prefabricated floor box, and the information wall seat and the power wall seat can be installed in the box. The termination and installation of information wall connector must be completed by professional engineers. Like the terminal of the management subsystem, its installation process has a direct impact on the performance of the system. Second, the construction technology requirements
The construction process is completed in three aspects: pipeline installation, cable installation and pipe fitting termination.
1. Pipeline installation: it is completed by an engineering team with the second-class qualification of telecommunication engineering installation in the telecommunications sector, and the process quality conforms to the relevant construction specifications of the national telecommunications sector and EIA/TIA569 standards. The welding of bridge and the transition connection of trunking meet the technical and safety requirements of high-voltage installation in national electrical standards.
2. Installation of stay wires: The open wiring system requires much higher skills for stay wire construction than other wiring systems, which is mainly determined by the characteristics of transmission media. In the open wiring system, there are generally two kinds of transmission media, one is twisted pair and the other is optical fiber. Although their material composition and transmission characteristics are different, they all require light pulling and light releasing when pulling wires. Irregular construction operation may lead to transmission performance degradation and even cable damage. In the construction, you can often see the following situations:
(1) Wrinkling or tearing of the outer cladding of twisted pair is caused by excessive tension, corner of trunking and unqualified transition connection.
(2) The outer coating of twisted pair is smooth, and no problems can be seen. However, it is found that the transmission performance can not meet the requirements when measured by instruments. This is because the tension is too large when pulling the wire, which makes the length of twisted pair elongate and twist straight. When this situation is used for voice and data transmission below 10Mbps, the impact may not be too great, but it will cause serious problems when it is used for high-speed data transmission. (3) There is no optical signal passing through the optical fiber, which is caused by improper operation when pulling the cable, and the fiber core is broken due to severe bending of the optical cable. This situation is common in the bending of optical fiber wiring.
In order to avoid the above problems in construction, ISO/IEC 1 1 standard EIA/TIA569 stipulates that the tension of twisted pair (especially twisted pair with more than 5 classes) when pulling cables shall not exceed 13 lbs (about 20kg). The tension of the optical fiber should not exceed 5 pounds (about 8 kilograms). In order to ensure the construction quality, it is stipulated that:
(1) When pulling wires, the length of each wire shall not exceed 20m, and someone must meet the excess; (2) someone must pick up and drop off at the corner of the line; 3. Accessories terminal:
The process level of accessory termination will directly affect the performance of wiring system. The company strictly controls it, and all termination operations will be completed by professional engineers. Third, the construction technology and technical requirements
1, in strict accordance with the drawings, on the premise of ensuring the functional quality of the system, improve the requirements of process standards and ensure the construction quality.
2, buried (left) location accurate, no omissions.
3. The wires at the equipment at both ends of the pipeline shall be sufficiently redundant according to the actual situation. Both ends of the conductor shall be marked according to the line number provided in the drawing, and the terminals shall be connected according to the line color, which shall be marked on the drawing and kept as construction data.
4, equipment installation is firm and beautiful, pre-installed equipment, columns, wall-mounted equipment is correct and consistent, data sorting is formal and complete, and all kinds of site change procedures are complete and effective. Laying of cables (wires)
In the wiring system, most signals are current signals or digital signals, so the following points should be paid attention to when laying cables (wires):
1, cable laying must be directed by a special person, and all construction personnel shall be disclosed before laying, indicating the number of cables laid, starting and ending numbers, process requirements and safety precautions.
2. Before laying the cable, prepare a sign indicating the number, model, specification, drawing number and starting point of the cable. 3. Before laying the cable, check whether all the grooves and pipes have been completed and meet the requirements, whether the wiring and the position of the information port to be installed meet the design, and determine whether there are any omissions.
4. Check whether the embedded pipe is unblocked and whether the wires in the pipe are in place. If not, it should be dealt with first.
5, check the pipeline before pay-off, before threading, the pipeline should be cleaned and polished smooth. Remove sundries and accumulated water in the pipeline. If possible, use 0.25Mpa compressed air to blow talcum powder to ensure threading quality. All metal trunking covers and guards shall be polished smooth and free of burrs to avoid scratching cables. 6. Check the specifications and models of cables.
7. When threading the pipe, the cable should be prevented from being excessively pulled, and the pulling force should not exceed 7kg per meter to protect the twisted distance.
8. When laying the cable, do not put the cable into a dead corner or tie a knot to ensure the good performance of the cable. When laying cables in horizontal trunking, the cables should be straight and avoid crossing as much as possible.
9, pay-off protection, can't damage the protective sleeve and trample cable.
10. For the area where smallpox is installed, all horizontal cable laying work must be completed before smallpox construction; All cables should not be exposed.
1 1. Wiring length: 3-5m copper cable, 7-9m optical cable, with 0.4m information outlet reserved for floor wiring room and equipment room (from trunking to ground and back again).
12, cable laying, both ends should be marked, cable labels should be clearly expressed, both ends of a cable should have consistent identification, and line labels should be clear and readable. When marking the line number, it is required to hold the line head with the left hand and the line tail to the right, so as to confirm the line number in the future.
13. Laying of vertical cables: threading shall be carried out from top to bottom. When laying, cables shall be placed in parallel, and shall not be twisted or crossed, bent or knotted. 14, optical cable should try to avoid heavy object extrusion.
15. Binding: Temporary binding should be carried out during threading to avoid binding after vertical tension, so as to reduce the influence of gravity sag on cable performance. After the trunk line is worn, it shall be bound as a whole, and the binding distance shall be ≤1.5m. Optical cables shall be bound separately in time. If there is any bending during binding, the bending radius shall not be less than 10CM.
16. Coaxial cables installed underground must be shielded with aluminum foil to prevent moisture.
17. The coaxial cable shall be inspected during installation, and the shielding layer shall not be damaged. 18, when installing cables, pay attention to ensure that the temperature of each cable is higher than 5? C.
19. Fill in the pay-off record: the number given by the main copper cable or optical fiber in the record should be clear about the floor number and serial number. 20, after the cable laying, both ends must have enough length, each corner, straight line should be sorted, confirmed by the commander to meet the design requirements before cutting.
2 1. After the cable is laid in the trunking, the trunking shall be covered to meet the requirements of fire prevention, moisture prevention and rat prevention.
Wiring in cabinet (box)
1. Install the rack and cabinet according to the design and installation drawing, and the installation screws must be tightened.
2, rack, cabinet installation should be aligned with the incoming position; During installation, the horizontal and vertical degree should be adjusted, and the deviation is not more than 3mm.
3. Install the distribution frame according to the installation drawing and design layout provided by the supplier. 4. The metal bases of racks, cabinets and distribution frames shall be well grounded. 5. Check whether the cable number is correct.
6. Before termination, the cables in the cabinet should be well bound, and the binding should be neat and beautiful. There should be a moving margin of about 1 meter. 7. When stripping the cable sheath, a special wire stripper should be used, and the insulation layer shall not be stripped, and the cable shall not be disconnected. 8. Before termination, the distribution frame termination table shall be prepared, and the cable shall be terminated according to the termination table. 9. Cables entering the cabinet (box) from the site shall be checked and numbered first. 10. Cables entering the cabinet (box) from the site shall be fixed.
1 1. The cable entering the cabinet (box) from the site should have a certain margin. 12. Cables entering the cabinet (box) from the site are generally not allowed to have connectors. 13. Cables entering the cabinet (box) from the site should avoid crossing each other as much as possible.
14, the wiring is correct according to the drawing, the connection is firm, the contact is good, the wiring is neat and beautiful, and the signs are clear. 15. The color of cable jumper with the same section should be as uniform as possible, which is convenient for installation, debugging and daily maintenance. Grounding requirements
1, bridge grounding mode, the application is not less than 2.5mm? The copper-plastic wire is grounded to the main reinforcement. 2. The grounding resistance of each cabinet and chassis shall not be greater than 1 ohm.
3. The equipment in the computer room adopts two independent grounding methods, namely the public grounding in working grounding. Working grounding resistance is not more than 4 ohms, and ordinary grounding resistance is not more than 1 ohm. During the debugging stage, attention should be paid to:
1, it is forbidden to power on immediately without inspection.
2, in strict accordance with the drawings and data, check whether the equipment installation and line laying of each subdivisional work are consistent with the drawings.
3. Check the installation and wiring of network equipment, PBX equipment and information points one by one. Fill in the quality feedback form when it is unqualified, and make corresponding records.
4. After all the equipment and points are checked, power on the equipment points one by one. 5. Only after the power-on experiment can the system be debugged. And make records.