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• 2020/9/29 13:26:55

Detailed interpretation of code for engineering design of generic cabling system

(1) Code for engineering design of generic cabling system (GB 50311)



According to the composition of the international standard system, according to the missing part of China's wiring standards, the chapter of industrial environment wiring is added, but the data center wiring system and home wiring system are not included in the scope of this specification. In order to better implement the strategic goal of "broadband China", Chapter 4 "fiber to user unit" is specially added in this specification, and the system composition, equipment configuration, product selection and performance index are proposed separately. In order to maintain the consistency with national standards such as building electrical, more space is added to the installation design.



The content changes of the new standard are as follows:



Supplement and improve the content of terms.



2. System design



·Referring to the international standard ISO / IEC 11801, the contents are digested, absorbed and cited equally. It is mainly reflected in the system classification, network topology, system composition, cable length, system index and so on.



·According to the original specification, the design content should be completed from seven parts: work area, distribution subsystem, trunk subsystem, building group subsystem, equipment room, incoming line room and management. But it will strengthen the setting requirements of the incoming line room, pay attention to the external network access and the technical requirements for the installation site of the entrance facilities.



Supplement the classification and composition of optical fiber cabling system.



·Considering the actual needs of the project, the current situation of the product, the technical development and the cost of the project, combined with the level setting of the wiring, the specific requirements of the product combination of the cable, information socket, wiring module and jumper for building support application in different application occasions and different levels of application are proposed.



·List the cable length limit of each subsystem of generic cabling system and the transmission distance that can be supported in various network applications. The requirements of cable length for each subsystem and network application in the system are different, which often leads to misunderstandings in the design, but it is particularly important for the design of wiring engineering system, which is the key to ensure the transmission performance of wiring.



·The selection principle and design points of shielded wiring system should be operable.



·According to the foreign standards, the design points of the open office wiring system are supplemented and modified when the multi-user information socket and assembly point are adopted.



3. System configuration



Compared with the 2007 edition, the content of this part will not only consider the actual needs of the project, but also leave redundancy and backup according to the actual situation of the project and the composition of the network. This part is the key part of the standard, which fully reflects the usability.



·The division area of work area is determined by different types of building functional areas.



·The configuration quantity of information socket.



·The configuration quantity and connection model of FD, BD, CD, various types of wiring module of entrance facilities, jumper configuration quantity and connection model of telecommunication room, equipment room and incoming line room are determined.



4. Management



Put forward the level, content and requirements of document and label management, and highlight the application requirements of intelligent wiring system.



5. System index



System indicators, in the international standard, provide two kinds of tables, which are recommended and need to be implemented. But in the design, we only pay attention to the technical index parameters provided by the recommended table, which are supplemented and improved.



·According to the composition of the permanent link and channel, the proposed performance index requirements are put forward.



·The index content that should be considered in shielded wiring system is put forward.



·The requirements of current, voltage and carrying power of copper conductor are put forward.



·The requirements of fiber channel index are put forward.



6. Installation process



·This paper puts forward the technical requirements for the setting of working area, telecommunication room, equipment room and incoming line room (such as doors, ambient temperature and humidity, dust, etc.), especially the area demand forecast of telecommunication room and equipment room.



·In cable laying, new correction data of bending radius, pipe diameter and pipe cross-sectional area utilization are listed.



·The comparison and application situation and requirements of open and closed cable laying.



7. Electrical protection and grounding



·This paper provides the requirements of the distance between comprehensive cable and power line, electrical equipment and other building pipelines, especially emphasizes the influence of interference source of electronic information system on the quality and safety of information transmission.



·The requirements of grounding index and grounding conductor are put forward. It is emphasized that the parts of wiring system need to be grounded and equipotential grounding and joint grounding.



·In particular, when the twisted pair cable is introduced from the outside of the building, the suitable surge protective device for signal line should be selected. This requirement is reserved as a mandatory provision.



8. Fire prevention



In the original specification, the international, North American and European cable fire test standards are listed in the same corresponding relationship. This standard will be put forward according to the classification requirements of current domestic standards on flame retardant cables for communication. Put forward more operational application terms.







(2) Code for engineering acceptance of generic cabling system (GB 50312)



Generally speaking, the new standard is only a partial improvement and supplement to the original specification, and the original structure has not been greatly changed.



1. Equipment and test instrument inspection



·Put forward the cable length sampling inspection.



·The requirements and proportion of cable sampling are put forward.



·It is emphasized to check the accuracy of test instruments and the integrity of tools.



2. In principle, the installation of equipment and the laying of cables shall meet the design requirements



3. The main protective measures for cables shall meet the design requirements.



4. Cable termination