I. Power cord
Power cord: It is a wire that transmits current. It is composed of outer sheath, inner sheath and copper wire.
1, RVV
Full name copper core PVC insulated PVC sheathed flexible cable. RVV line, the appearance of the round, the number of cores is more, and between the two cores are stranded. R stands for flexible wire, and the letter V stands for PVC, an insulator. Main USE of RVV CABLE: Used in electrical appliances, instruments, electronic equipment and automation devices and other power lines, control lines and signal transmission lines that do not need shielding.
Commonly used RVV wire models are: RVV2*0.5,RVV2*0.75,RVV2*1.0, such as: RVV2*1.5 -- 2 means 2 wire core, 1.5 means the cross-sectional area of a wire core (unit is 2)
2, RVVP
Full name copper core PVC insulated PVC shielded flexible cable. Suitable for communication, audio, broadcast, sound system, anti-theft alarm system, intelligent automation system, automatic meter reading system, fire protection system and other need to prevent interference line connection, efficient and safe transmission data cable. The letter R stands for cord, the letter V for insulator polyvinyl chloride (PVC), and the letter P for shielding. RVVP can be used in monitoring system, access control system, building visual intercom system, building control system control line.
Differences between RVV and RVVP:
Compared with RVV, RVVP has a layer of shielding braded net, and PVVP line has a layer of copper wire mesh between the inner and outer sheath as a shielding layer ----. The shielding layer is mainly to prevent the influence of external electromagnetic field, so as to improve the anti-interference balance degree of wire.
3. AVVR cable
Full name copper conductor PVC insulated PVC sheathed flexible cable for installation. Usually used for weak current power supply.
Differences between RVV and AVVR:
AVVR and RVV are the same wire. Models above 0.5 square meters are classified as RVV(including 0.5 square meters) and models below 0.5 square meters are classified as AVVR.
4, BV
Full name copper core PVC insulated wire, BV wire is also referred to as plastic copper wire, where B represents the category, belongs to the cloth wire, V represents the insulation for PVC, generally applicable to AC voltage 450/750V and below electrical instrumentation equipment and power lighting fixed wiring and other power supply.
The BV line is further divided into ZR-BV and NH-BV
1)ZR-BV: copper core PVC insulated flame retardant wire: insulating material with flame retardant, leaving the open flame does not spontaneously ignite. Flame retardant BV line is divided into A, B, C, D four grades, A class is the best, and so on, the most commonly used for ZB-BV.
2)NH-BV: copper core PVC insulated refractory wire: normal fire can also be used normally.
5, BVR
BVR polyvinyl chloride insulated flexible wire. BVR wire, generally referring to BVR power cord, is a kind of copper core PVC insulated flexible wire, which is used in fixed wiring requirements of soft occasions. B refers to the classification belongs to cloth wire, V refers to PVC polyvinyl chloride, also known as "plastic", R refers to the meaning of soft, to achieve soft, it is necessary to increase the number of conductor roots.
BVR wire according to the choice of different materials, also divided into flame retardant wire (ZR-BVR), refractory wire (NH-BVR), low smoke halogen free wire (WDZ-BVR). Mainly used in electrical instrumentation equipment and power lighting fixed wiring.
Differences between BV and BVR:
A. In terms of production technology,BV is single-core while BVR is multi-core. In terms of production, BVR is more complicated than BV.
B. In terms of price, BV and BVR are a little more expensive than BV because they are only in technology.
C. In terms of performance, BV is basically the same as BVR, but BVR is a little heavier in weight.
6, UL 2464
Multi - core shielded wire for computer connection.
7, RVB
RVB is flat sheath free flexible wire, commonly known as red and black (parallel) wire. Suitable for household appliances, small power tools, instruments, meters and power lighting connection.
8 RVVB.
RVVB is flat sheath cord, RVVB and RVB use the same, the difference is that RVB is flat sheath cord, and RVVB is flat sheath cord, so RVVB has a layer of sheath than RVB.
9, RVS
RVS wire full name: copper core PVC insulated twisted type connection with flexible wire, twisted multiple strands of flexible wire, referred to as twisted pair, commonly known as "flower wire", at this stage this wire is mostly used in fire fighting system, also called "fire line". The letter S stands for twisted pair, the letter R stands for flexible wire, and the letter V stands for PVC (insulator).
Use of RVS twisted pair:
1. It is mainly used for the detector line of fire automatic alarm system
2. Suitable for household appliances, small power tools, instruments and power lighting line. Double white core for direct connection of lamp head line; Red and blue core for fire fighting, alarm, etc. Red and white core for broadcasting, telephone lines; Red and black cores are used for broadcast wires.
3. Used for connecting power amplifier and audio equipment, broadcasting system to transmit audio signals amplified by the power amplifier.
The difference between RVS and RVB is that RVB is a parallel flexible wire and RVS is a twisted pair flexible wire
Second, video line
Video cable: A coaxial cable used to transmit video baseband analog signals.
1, SYV
Full name solid polyethylene insulated radio frequency coaxial cable. S-- coaxial radio frequency cable,Y-- polyethylene,V-- PVC. It is usually used in analog monitoring system, visual intercom system and cable TV system to transmit video signals.
SYV video cable specifications are as follows:
Syv75-3 transmission range 100-300 meters;
Syv75-5 transmission range 300-500 meters;
Syv75-7 transmission range 500-800 meters;
Syv75-9 transmission range 1000-1500 meters;
Syv75-12 transmission range 2000-3500 meters;
Syv75-3-75 indicates that the impedance is 75 ohms, and -3 indicates the thickness of the wire.
2, SYWV
Full name POLYETHYLENE physical foam INSULATED coaxial cable, usually used for satellite TV transmission and cable TV transmission, long-distance visual INTERcom system special cable, suitable for radio frequency transmission.
SYV is the same as SYWV
A. The characteristic impedance is the same -- 75 ohms;
B. Outer sheath, shielding layer structure, insulation layer diameter, number selection, material selection, shielding layer number and so on are basically the same.
SYV is different from SYWV
A. The insulation layer has different physical characteristics: SYV is filled with 100% polyethylene, SYWVD is also filled with polyethylene, but it is filled with 80% nitrogen bubbles, and polyethylene only contains 20%
B. Core wire diameter is different: 0.78-0.8mm for SYV cable and 1.0mm for SYWV cable
C. Transmission characteristics of the two cables -- transmission attenuation is different.
3, VGA line
An analog signal video cable most commonly used in computer and monitor connections.
4, RG
Physical foamed polyethylene insulated access network cable, usually used for weak current video image transmission or hybrid fiber coaxial cable network (HFC network) transmission data analog signal. And so on according to use can be divided into two basic types: baseband coaxial cable and broadband coaxial cable. At present, the commonly used baseband cable, its shielding wire is made of copper mesh, the characteristic impedance is 50(such as RG-8, RG-58, etc.); The shielding layer of wideband coaxial cable is usually stamped with aluminum and has a characteristic impedance of 75(e.g. Rg-59, etc.). In RG-58/59, RG is the number of the radio frequency cable series. RG plus different numbers represent the radio frequency cable with different structure and performance.
The most commonly used are the following:
Rg-8 or RG-11(50 ω),
RG - 58 (50 Ω),
RG - 59 Ω (75),
RG - 62 (93 Ω)
Rg-8 Ethernet thick cable and RG-58 Ethernet thin cable are generally used in computer networks. Rg-59 for television systems. Rg-62 is used in ARCnet network and IBM3270 network.
Generally, it is installed between devices. Each user location is equipped with a connector that provides an interface to the user. To install the interface, perform the following steps:
(1) Thin cable Cut the thin cable, install the BNC head at both ends, and then connect it to both ends of the T-connector.
Thick cable The thick cable is generally installed by a Tap device similar to a splint, which uses the guide needle on the Tap to penetrate the insulation layer of the cable and directly connect with the conductor. Terminals are arranged at both ends of the cable to weaken the reflection of the signal.
5, AV line
It is the abbreviation of Audio Cable (Audio Cable) and Video Cable (Video Cable) in family acoustics, so it is also called Audio and Video Cable. Mainly used for audio equipment, home video equipment audio and video signal connection.
Three, network cable, network cable
1. Shielded twisted pair cable
1)STP
STP shielded twisted pair has a metal isolation film in the twisted pair, which can reduce electromagnetic interference and prevent information from being eavesdropped during data transmission. Therefore, it has high stability and high data transmission rate. STP twisted pair of the price of perhaps, cheap a few yuan 1 meter, expensive may be more than 10 yuan 1 meter.
2)FTP
The differences between FTP and STP are as follows: STP is a shielded twisted pair with its own masking layer, whereas FTP is a shielded twisted pair with its own masking layer. It is important to note that shielding only works if the entire cable is shielded and both ends are properly grounded. Therefore, the whole system is required to be shielded devices, including cables, sockets, crystal heads and distribution frames, and the building needs to have a good ground system.
2. Unshielded twisted pair cable
UTP
LAN cable, mainly used for transmitting telephone, computer data, fire prevention, anti-theft security system, intelligent building information network, UTP(unshielded twisted pair) does not have this layer of metal film, so its stability is poor, but its advantage is cheap, flexible networking, flame retardant effect is good, not easy to cause fire. The price of twisted-pair cable with UTP is generally about 1 yuan per meter.
Compares the performance indicators of a shielded twisted pair (STP) and an unshielded twisted pair (UTP)
According to the electrical performance, it can be divided into 9 types: class 1, class 2, class 3, class 4, class 5, Class 5, class 6, class 6, class 7. The larger the type number, the newer the version, the more advanced the technology, the wider the bandwidth and, of course, the more expensive the price. These different types of twisted pairs are labeled as follows: if they are standard types, they are labeled as "CATX". For example, the commonly used Category 5 lines, the outer envelope of the lines is labeled as "CAT5". Note that the letters are usually lowercase, not uppercase. If it is an improved version, it will be labeled as "XE". If it is a category 5 line, it will be labeled as "5E". Again, the letters will be lowercase, not uppercase.
1) First class line:
Mainly used to transmit telephone voice (a class of standards mainly used in telephone cables before the early 1980s), as opposed to data transmission.
2) Second class line:
The transmission frequency is 1MHZ for voice transmission and data transmission with a maximum transmission rate of 4Mbps, which is commonly seen in older token networks using the 4Mbps canonical token passing protocol.
3) Three types of lines:
The cable is specified in ANSI and EIA/TIA568 standards, the transmission frequency of the cable is 16MHz, for voice transmission and the highest transmission rate of 10Mbps data transmission, dedicated to 10BASE-T Ethernet.
4) Four types of lines:
The cable has a transmission frequency of 20MHz for voice transmission and a maximum transmission rate of 16Mbps for data transmission, which is mainly used in token-based lans and 10base-t / 100base-t.
5) Five types of lines:
The cable has increased winding density, is coated with a high quality insulation material, and has a transmission rate of 100MHz. It is used for voice transmission and data transmission with a maximum transmission rate of 100Mbps. It is mainly used in 100base-t and 10base-t networks. This is the most commonly used Ethernet cable.
6) Super five lines:
The super 5 class has low attenuation, less crosstalk, higher attenuation to crosstalk ratio (ACR), Structural Return Loss (SNR), and smaller delay error, and the performance is greatly improved. Super class 5 lines are mainly used for gigabit Ethernet (1000Mbps).
7) Six types of lines:
The transmission frequency of this type of cable is 1MHz ~ 250MHz, and the integrated Attenuation crosstalk ratio (PS-ACR) of the six type wiring system should have a large margin at 200MHz, which provides twice the bandwidth of the super five type. The transmission performance of six types of wiring is much higher than that of the super five types of standards, and it is most suitable for the application of transmission rate higher than 1Gbps. It is mainly used in the hundred megabit fast Ethernet and gigabit Ethernet.
An IMPORTANT DIFFERENCE BETWEEN CLASS 6 and SUPER CLASS 5 IS THE IMPROVED PERFORMANCE IN terms OF CROSSTALK AND return LOSS, which is very important for the new generation of full-duplex high-speed network applications. The basic link model is cancelled in the six types of standards, and the wiring standard adopts the star topology structure. The required wiring distance is: the length of the permanent link cannot exceed 90m, and the length of the channel cannot exceed 100m.
8) Super six lines:
Super Class 6 cable is a modified version of Class 6 cable. It is also an unshielded twisted pair cable specified in ANSI/EIA/TIA-568B.2 and ISO Class 6 / Class E standards, mainly used in gigabit networks. In terms of transmission frequency, it is also 200 ~ 250 MHz, and the maximum transmission speed can reach 1 000 Mbps, just in the crosstalk, attenuation and signal-to-noise ratio and other aspects of great improvement.
9) Seven types of lines:
The twisted-pair cable is one of the latest twisted-pair cables in the ISO 7 /F standard. It is mainly designed to adapt to the application and development of ten gigabit Ethernet technology. But it is no longer a kind of unshielded twisted pair, but a kind of shielded twisted pair, so its transmission frequency can reach at least 500 MHz, which is more than twice as high as the class 6 line and super class 6 line, the transmission rate can reach 10 Gbps.
There are two connection methods: straight-through cable and crossover cable.
A) Both ends of the water lens of the straight-through cable comply with the 568A or 568B standard. Each group of twisted pair cables corresponds to each other at both ends. The cables of the same color must be consistent in the corresponding slots of the water crystal heads at both ends. It is used to connect the switch (or hub)Uplink port to a common switch (or hub) port or a common switch port to a computer NIC.
B) and the crystal head end of the crossover cable follow 568 A, while the other end with 568 b standard, namely A crystal head 1, 2, corresponding b crystal head 3, 6, and A crystal head 3, 6 corresponding b crystal head 1, 2, it is mainly used in switches (or hub) ordinary port connected to the switch (or hub) ordinary port or network card even on the card.
Four, elevator cable
Elevator cable: is composed of coaxial cable (generally SYV-75-3 + TVVB 2X1.0, SYV-75-4 + TVVB 2X1.0), if you need other models can be customized. There are reinforced steel wire and nylon rope inside, and fiber tissue. The outer sheath is made of super soft PVC material, which effectively increases tensile resistance
