How to select cables for the cabling system
Definition of integrated wiring cable: Integrated wiring system Wire and cable refers to materials used for electric power, communication and related transmission purposes. There is no strict line between "wire" and "cable".
Usually the number of cores, small product diameter, simple structure of the product is called wire, no insulation is called bare wire, the other is called cable; Conductor cross-sectional area is larger (greater than 6 square millimeters) known as large wire, smaller (less than or equal to 6 square millimeters) known as small wire, insulated wire is also known as cloth wire. Wire and cable mainly includes bare wire, electromagnetic wire and electrical electrical insulation wire, power cable, communication cable and optical cable.
I. How to select cables for the cabling system
With the rapid development of domestic urbanization, the construction industry is still vibrant. Today's society has opened the mode of smart city, and the trend of intelligent management has been quietly integrated into domestic public facilities, high-rise buildings and even residential communities. The future building will be intelligent building, intelligent management has become an essential part of our life.
In today's society, intelligent building has become an inevitable trend in the future of the construction industry. According to the data of "2013-2017 China Intelligent Building Industry Development Prospects and investment strategy Planning Analysis Report", the development of domestic intelligent buildings has been rapid, the annual growth of 20%, in 2005 exceeded 20 billion yuan for the first time, the development has reached 86.1 billion yuan in 2012.
In this trend of intelligent and rapid development, the nervous system of intelligent buildings, that is, the integrated wiring system, is more important and indispensable. In the ordinary construction industry, communication cables are infrastructure; In intelligent buildings, the cabling system becomes the most critical and basic part.
The planning and design of building engineering, construction, installation and maintenance are closely related to the use of integrated wiring. As the nervous system of intelligent building, it is responsible for the important task of collecting and conveying information, and has become a bridge for our communication and communication.
In other words, the cabling system plays the role of closely connecting communication equipment, computers and other facilities in intelligent buildings, and provides a good support for a high degree of intelligence. At this time, the problem of fire prevention has become a special need to pay attention to and consider the factors. If a fire occurs inside the building, the cables will release a large amount of heat and poison gas, which may cause serious safety hazards.
It is not hard to imagine that in several large fire accidents that have occurred frequently in China in recent years, the tragedy occurred because the cables released toxic gas in the high temperature, as well as the heat and smoke caused by the burning, which resulted in the trapped victims unable to breathe and finally difficult to escape.
Therefore, in the current domestic market, there are grades of communication cables, and the difference lies in the material of cable sheath. 2007 "Cabling engineering design Code GB50311 -- 2007" for the cable fire protection and environmental protection grade division, according to this specification, the market users can better choose different levels of fire and environmental protection cable to meet different requirements. In general, the cable sheath on the market is mainly divided into three kinds, which are ordinary (PVC) type; Low smoke halogen free type (LSZH/LS0H) and refractory type (Fireresistant).
First of all, on the site with raised floor or ceiling, if the built-in PVC trough and the installation of air conditioning and ventilation system, Xiaobian will recommend users to use flame-retardant (CMP or OFNP) comprehensive cabling cable; For built-in metal grooves/pipes or fireproof PVC grooves/pipes, the small editor suggests that users can use arbitrary fire rating (CM//CMR/CMP or OFN/OFNR/OFNP) comprehensive wiring cables;
LSZH cables are suitable for crowded places, such as stations, subways, airports, hospitals, and convention and exhibition centers. Because crowded occasions have the highest requirements for environmental protection and fire protection, after selecting the highest level of comprehensive wiring and cables, Xiaobian also suggests that users should also use metal grooves/pipes or flame retardant PVC grooves/pipes with fire protection function.
Second, what are the differences between the cables of the comprehensive cabling system
Difference between SYV and SYWV: SYV is a video transmission line and is insulated with polyethylene. SYWV is radio frequency transmission line, physical foam insulation. Used for cable television.
RVS and RVV 2-core difference: RVS is twin-core RV wire stranded, without outer sheath, used for broadcast connection. RVV 2 Core wire is directly laid into cable, with outer sheath, used for power supply, control signal, etc.
RVV and KVV RVVP and KVVP Difference: The wires used in RVV and RVVP are flexible wires composed of multiple strands of fine copper wires, namely, RV wires. The wire used in KVV and KVVP is a hard wire composed of single thick copper wire, that is, BV wire.
Differences between AVVR and RVVP: AVVR indicates that the wire diameter is smaller than 0. For 5MM unshielded cable, RVVP indicates that the cable diameter is greater than or equal to 0. 5MM shielded cable.
RVS and RVV 2-core difference: RVS is twin-core RV wire stranded, without outer sheath, used for broadcast connection. RVV 2 Core wire is directly laid into cable, with outer sheath, used for power supply, control signal, etc.
About the comprehensive cabling system cable knowledge, today Xiaobian first for you to say here. Of course, in the selection of cabling system cable, we can also choose by use, such as video signal transmission generally adopts direct modulation technology, in the form of baseband frequency (about 8MHz bandwidth), the most commonly used transmission medium is coaxial cable; Coaxial cable is specially designed to transmit video signal, its frequency loss, image distortion, image attenuation amplitude are relatively small, can be very good to complete the task of transmitting video signal.