Integrated wiring is one of the key links of information network system, it is very important to choose high quality and high performance cable in order to ensure the high-speed and stable operation of information network system.
Cable selection should be based on the requirements of the system, technical performance, investment estimates and other factors, but in the wiring system should first determine the use of cable categories and wiring structure (unshielded cables, shielded cables, optical cables or several mixed use). Cables usually use wires with insulating layers and use one or more layers of plastic skin. Cables typically consist of 2 to 3,600 lines. Large-log cables are commonly used in backbone cabling systems that are suitable for use in voice and low speed data transmission. The maximum length of these cables in the application of the trunk and level (hub to desktop) cabling system is described in detail in the latest gb50311-2007. It is important to note that these maximum length limits apply to all media. They do not consider the impact of performance differences due to the different cable types and protocol types used by the network. In fact, the maximum cable length will depend on the system's application, network type, and cable quality.
The method of cable selection in integrated cabling system
According to the "2013-2017 China Intelligent Building Industry development prospects and Investment Strategic Planning Analysis Report" data show that China's intelligent building industry market in 2005, the first breakthrough 20 billion yuan, but also more than 20% annual growth trend, 2012 market size reached 86.1 billion yuan. From the data point of view, intelligent building in recent years in the domestic development speed, which also shows that intelligent building is a major trend in the future development of architecture.
Since it is a building, it will certainly use a lot of communication cables. As the integrated wiring system of nervous system in intelligent building, it is the key part and infrastructure of intelligent building, which is closely related to the planning, design, installation and maintenance of construction. It is like a building in the information superhighway, people in this channel convenient, fast, effective communication and communication. It can be said that the integrated wiring system in the Intelligent building communication, computer and all kinds of facilities and equipment connected to form a complete package of the whole to meet the requirements of highly intelligent.
But then we have to consider a problem: fire. The heat and gas released by these cables will be a major safety hazard in the event of a fire in the building. In recent years there have been several major domestic fire accidents, many of them because the victims can not escape, cable burning emitting toxic acid gas, coupled with the burning of a large amount of heat, smoke, causing the victims breathing difficulties, resulting in tragedy. Therefore, in addition to considering the performance, fire prevention and environmental protection are also very important reference factors in the selection of cabling system.
China in 2007 promulgated the "Integrated wiring Design Code gb50311-2007" for the first time introduced a cable fire and environmental protection level, the guidelines suggest that domestic users according to different occasions to choose a different level of fire or environmental protection cable.
The current domestic market communication cable sheath material is divided into three main types:
1. General (PVC) type;
2, low smoke halogen-free type (lszh/ls0h);
3. Refractory type (fireresistant). Integrated wiring cable fire protection or environmental grade selection should be based on the actual situation in the field of thinking:
Overhead floor or ceiling
If the overhead floor or ceiling of the building is PVC wire slot/tube and the air conditioning ventilation system is installed, flame-retardant (CMP or OFNP) cables should be used in overhead floors or ceilings, and if the overhead floor or ceiling of a building is provided with a metal wire slot/tube or a fireproof PVC wire slot/tube, it can be used at random fire grade (cm// CMR/CMP or OFN/OFNR/OFNP) cable. For buildings with environmental protection needs such as crowded places (airports, subways, stations, hospitals, exhibition centers, etc.), the design of integrated wiring projects suitable for the use of Lszh grade cable, at the same time should be used fire-resistant metal wire slot/tube or flame retardant PVC wire slot/tube.
Vertical Shaft
If the vertical shaft of the building is PVC wire groove (wire pipe), vertical shaft should be used in vertical level (CMR or OFNR) above grade of cable or optical cable, vertical shaft If the metal wire slot/pipe (or flame retardant PVC wire groove/pipe), vertical shaft can be used at random fire rating (CM/CMR/CMP or ofn/ OFNR/OFNP) Cable.
The above analysis, in addition to design staff in the design to consider the cable technical performance indicators, and other factors, such as line, construction and installation personnel must also ensure that according to the design requirements and standardize the organization of construction, acceptance personnel must be strictly in accordance with the specifications and design testing and acceptance, so as to ensure the information network high-quality, high-performance operation. If there is no integrated wiring system in the intelligent building, all kinds of facilities and equipment will not be able to operate properly because of no information transmission medium, and it is difficult to realize the intelligence. and the choice of system cable has also become an important factor, here, we also remind you that the choice of integrated cabling system cable, in addition to considering performance, fire and environmental protection should also be taken into account, to enhance the safety index inside the building.