Common Low voltage cable

Updated: May 30, 2019

The power line a current transmission wire, an outer sheath, the inner sheath copper wires.

1, RVV

Full name copper core PVC insulated PVC sheathed flexible cable. RVV line, the appearance of the round shape, the number of cores is more, and there are strands between the two cores. R stands for the cord and the letter V stands for the insulator polyvinyl chloride (PVC). Main use of RVV cable: It is applied to power lines, control lines and signal transmission lines that do not need to be shielded, such as electrical appliances, instruments and electronic equipment, and automation devices.

Commonly used RVV wire types are: RVV2*0.5, RVV2*0.75, RVV2*1.0,

such as: RVV2*1.5 ——2 means 2 cores, 1.5 means the cross-sectional area of one core (unit is mm2)


Full name copper core PVC insulated polyvinyl chloride shielded flexible cable. It is suitable for communication, audio, broadcasting, audio system, anti-theft alarm system, intelligent automation system, automatic meter reading system, fire protection system, etc. It needs anti-interference line connection, efficient and safe transmission data cable. The letter R stands for the cord, the letter V stands for the insulator polyvinyl chloride (PVC), and the letter P stands for the shield. RVVP can be used specifically for monitoring systems, access control systems, building video intercom systems, and control lines in building control systems.


Fully called copper core PVC insulated PVC sheathed flexible cable for installation. Usually used for weak current power supply.

The difference between RVV and AVVR:

AVVR and RVV are the same wire. Models with a size of 0.5 square or more are classified as RVV (including 0.5 square) and models below 0.5 square are classified as AVVR.

4, BV

Full name is copper core PVC insulated wire, BV line is also called plastic copper wire, of which B is a category, belonging to cloth wire, V means insulation is PVC, generally suitable for AC voltage 450/750V and below electrical instrumentation and power Supply of electricity such as lighting fixed wiring.

The BV line is further divided into: ZR-BV and NH-BV

1) ZR-BV: Copper core PVC insulated flame-retardant wire: Insulating material is added with flame retardant, leaving the open flame and not self-igniting. Flame-retardant BV lines are divided into four grades A, B, C, and D, of which Class A is the best, and so on. The most commonly used is ZB-BV.

2) NH-BV: Copper core PVC insulated fire-resistant wire: It can be used normally under normal fire conditions.

5, BVR

Full name BVR PVC insulated flexible wire. The BVR cable, generally referred to as the BVR power cord, is a copper-core PVC insulated flexible cord that is used in applications where soft wiring is required for fixed wiring. B means that the classification belongs to the cloth wire, V refers to PVC polyvinyl chloride, also commonly known as "plastic",

R means soft, to be soft, it is necessary to increase the number of conductors.

Depending on the choice BVR wire material, the wire is also divided into flame retardant (ZR-BVR), refractory wire (NH-BVR), low smoke zero halogen wire (WDZ-BVR). Mainly used in electrical power and instrumentation wiring lighting fixture.

The difference between BV and BVR:

a. From the production process, BV is single-core, BVR is multi-core, BVR is more complicated than BV in production.

b. From the price point of view, BV and BVR are more expensive than BV because they are only in the process.

c. At performance, BV substantially identical with BVR, BVR slightly heavier weight.

6, UL 2464

Multi-core shielded cable for computer cable.

7, RVB

RVB is unsheathed flexible flat cable, commonly known as red and black (parallel) line. It is suitable for household appliances, small power tools, instruments, meters and power lighting.


RVVB is a flat sheathed cord. RVVB is equivalent to RVB. The difference is that RVB is a flat, unsheathed cord, and RVVB is a flat sheathed cord, so RVVB has a more sheath than RVB.

9, RVS

RVS wire full name: copper core PVC insulated stranded connection soft wire, twisted multi-strand soft wire, referred to as twisted pair, commonly known as "flower line",

at this stage, this kind of wire is mostly used in fire protection system,

also called "fire line" ". The letter S stands for twisted pair, the letter R stands for cord, and the letter V stands for polyvinyl chloride (insulator).

Use of RVS twisted pair:

1. Detector line for fire alarm automatic alarm system

2. Suitable for household appliances, small power tools, instrumentation and power lighting. Double white core is used for direct connection to the lamp line; red and blue core is used for fire protection, alarm, etc.; red and white core is used for broadcasting and telephone line; red and black core is used for broadcasting line.

3. It is used to connect the amplifier and audio equipment, and the broadcast system transmits the audio signal amplified by the power amplifier.

The difference between RVS and RVB is that RVB is a parallel cord and RVS is a twisted pair cord.

The video cable: A coaxial cable used to transmit a baseband analog video signal.

1, SYV

Full name solid polyethylene insulated RF coaxial cable. S---coaxial RF cable, Y---polyethylene, V---polyvinyl chloride. It is commonly used in analog surveillance systems, video intercom systems, and cable television systems to transmit video signals.

The specifications of the SYV video cable are:

SYV75-3 transmission distance 100-300 meters;

SYV75-5 transmission distance 300-500 meters;

SYV75-7 transmission distance is 500-800 meters;

SYV75-9 transmission distance 1000-1500 meters;

SYV75-12 transmission distance 2000-3500 meters;

SYV75-3—75 represents an impedance of 75 ohms, and -3 represents the thickness of the wire.


Fully-called polyethylene physical foamed insulated coaxial cable, usually used for satellite TV transmission and cable transmission, long-distance video intercom system dedicated cable, suitable for RF transmission.

The same point of SYV and SYWV

a. The same characteristic impedance - 75 ohms;

b. Outer sheath, shield structure, outer diameter of insulation layer, number selection, material selection, shielding layer, etc. are basically the same.

Difference between SYV and SYWV

a. The physical properties of the insulation layer are different: SYV is 100% polyethylene filled, SYWVD is also filled with polyethylene, but filled with 80% of nitrogen bubbles, polyethylene only contains 20%

b. Different core diameters: 0.78-0.8mm for SYV cable and 1.0mm for SYWV cable

c. The transmission characteristics of the two cables - the transmission attenuation is different.

3, VGA cable

It is an analog signal video cable, most commonly connected to a computer and display.

4, RG

The full name is a physical foamed polyethylene insulated access network cable, which is usually used to transmit data analog signals in weak video image transmission or hybrid fiber coaxial cable network (HFC network). According to the use, it can be divided into two basic types: baseband coaxial cable and broadband coaxial cable. At present, the commonly used cable for the baseband has a mesh line made of copper and has a characteristic impedance of 50 (such as RG-8, RG-58, etc.); the shield of the commonly used cable for the wideband coaxial cable is usually stamped with aluminum.

The characteristic impedance is 75 (such as RG-59, etc.). RG-58/59 RG is the number of the RF cable series, RG plus different numbers to represent the RF cable with different structure and performance.

The most common ones are the following:

RG-8 or RG-11 (50Ω),

RG-58 (50Ω),

RG-59 (75Ω),

RG-62 (93Ω)

The computer network generally uses RG-8 Ethernet thick cable and RG-58 Ethernet thin cable. The RG-59 is used in television systems. The RG-62 is used in the ARCnet network and the IBM 3270 network.

Generally installed between the device and the device. A connector is provided at each user location to provide an interface to the user. The installation method of the interface is as follows:

(1) Thin cable Cut the thin cable, put the BNC head on both ends, and then connect it to the T-connector.

(2) Thick cable The thick cable is usually installed by a tap device like a splint. It uses the guiding pin on the Tap to penetrate the insulation layer of the cable and directly connect to the conductor. Terminals are provided at both ends of the cable to attenuate the reflection of the signal.

5, AV line

It is the abbreviation of Audio Cable and Video Cable in Home Audio, so it is also called audio and video cable. Mainly used for audio equipment, audio and video signal connections for home video equipment.

The network cable, network cable

1. Shielded twisted pair

1) STP

The STP shielded twisted pair twisted pair has a metal isolation film to reduce electromagnetic interference during data transmission and prevent information from being eavesdropped. Therefore, it has high stability and high data transmission rate. The price of STP twisted pair is uncertain. A few yuan is cheaper than 1 meter, and expensive may be more than ten yuan and one meter.

2) FTP

FTP and STP are similar. The difference between the two is that STP refers to a shielded twisted pair with a separate shield for each line, while FTP uses a shielded twisted pair with an overall shield. It should be noted that the shielding only works if the entire cable has shielding and the two ends are properly grounded. Therefore, the entire system is required to be shielded devices, including cables, sockets, crystal heads and patch panels, and the building needs to have a good grounding system.

2, unshielded twisted pair


LAN cable, mainly used for transmission telephone, computer data, fire prevention, anti-theft security system, intelligent building information network, UTP (unshielded twisted pair) does not have this metal film, so its stability is poor, but its advantages The price is cheap, the networking is flexible, the flame retardant effect is good, and it is not easy to cause fire. The price of twisted pair using UTP is generally around 1 meter and 1.5 yuan.

According to the electrical performance, it can be divided into: Category 1, Category 2, Category 3, Category 4, Category 5 cable, Category 5e, Category 6 cable, Category 6A, and Category 7. The larger the type number, the newer the version, the more advanced the technology, and the wider the bandwidth, of course, the more expensive the price. These different types of twisted pair marking methods are specified as follows: if it is a standard type, it is marked as "catx". For example, the commonly used type 5 line is marked as "cat5" on the online package. Note that the letters are usually lowercase. Instead of capitalizing. If it is an improved version, it will be marked with "xe". For example, if the super 5 line is marked as "5e", the same letter is lowercase instead of uppercase.

1) Category 1 line: mainly used to transmit telephone voice (a type of standard is mainly used for telephone cables before the early 1980s), which is different from data transmission.

2) Category 2 line: The transmission frequency is 1 MHz, which is used for voice transmission and data transmission with a maximum transmission rate of 4 Mbps. It is commonly used in the old token network using the 4 MBPS specification token transfer protocol.

3) Category 3: A cable specified in the ANSI and EIA/TIA568 standards. The cable has a transmission frequency of 16 MHz and is used for voice transmission and data transmission with a maximum transmission rate of 10 Mbps. It is dedicated to 10BASE-T Ethernet.

4) Category 4 cable: This type of cable has a transmission frequency of 20 MHz. The data transmission for voice transmission and maximum transmission rate of 16 Mbps is mainly used for token-based LAN and 10BASE-T/100BASE-T.

5) Category 5 cable: This type of cable increases the winding density, jacket is a high quality insulation material, transmission rate is 100MHz, used for voice transmission and data transmission with a maximum transmission rate of 100Mbps, mainly used for 100BASE-T and 10BASE-T network. This is the most commonly used Ethernet cables.

6) Category 5E: Category 5E has low attenuation, low crosstalk, and higher attenuation and crosstalk ratio (ACR) and signal loss ratio (Structural Return Loss), smaller delay error, and very good performance. Great improvement. The Super Category 5 cable is mainly used for Gigabit Ethernet (1000 Mbps).

7) Category 6 cable: The transmission frequency of this type of cable is 1MHz ~ 250MHz. The Category 6 wiring system should have a large margin in the integrated attenuation crosstalk ratio (PS-ACR) at 200MHz, which provides twice the super five class. bandwidth. The transmission performance of Category 6 cabling is much higher than the Category 5 standard, and is best suited for applications with transmission rates higher than 1 Gbps. It is mainly used in 100 Mbps Fast Ethernet and Gigabit Ethernet.

An important difference between Category 6 and Category 5 is that it improves performance in terms of crosstalk and return loss. For a new generation of full-duplex high-speed network applications, excellent return loss performance is extremely important. The basic link model is eliminated in the six categories of standards. The cabling standard adopts a star topology. The required cabling distance is: the length of the permanent link cannot exceed 90 m, and the channel length cannot exceed 100 m.

8) Category 6A line: Super Category 6 line is an improved version of Category 6 line, also an unshielded twisted pair cable as specified in ANSI/EIA/TIA-568B.2 and ISO Class 6/E standards. Mainly used in gigabit networks. In terms of transmission frequency, like the Category 6 line, it is also 200-250 MHz, and the maximum transmission speed can reach 1 000 Mbps, but it has a great improvement in crosstalk, attenuation and signal-to-noise ratio.

9) Category 7: This line is the latest twisted pair in the ISO 7/F standard. It is mainly used to adapt to the application and development of 10 Gigabit Ethernet technology. But it is no longer an unshielded twisted pair, but a shielded twisted pair, so its transmission frequency is at least 500 MHz, which is more than twice the transmission of Category 6 and Super 6 lines. Up to 10 Gbps.

There are also two main connection methods: straight-through cable and crossover cable.

a) Both ends of the water lens of the straight-through cable follow the standard of 568A or 568B. Each line of the twisted pair has a one-to-one correspondence at both ends, and the same color is consistent in the corresponding slots of the water crystal heads at both ends. It is mainly used in the switch (or hub) Uplink port to connect to the switch (or hub) common port or switch common port to the computer network card.

b) The end of the crystal head of the crossover cable follows 568A, while the other end uses the 568B standard, that is, the 1 and 2 of the A crystal head correspond to the 3, 6 of the B crystal head, and the 3 and 6 of the A crystal head correspond to the B crystal head. 1, 2, it is mainly used in the switch (or hub) common port to connect to the switch (or hub) common port or network card to the network card.

The elevator cable

The elevator cable: is a combination of a coaxial cable (typically SYV-75-3 + TVVB 2X1.0, SYV-75-4 + TVVB 2X1.0) together, if desired other models can be customized. It has reinforced steel wire and nylon rope, and fibrous structure. The outer sheath is made of super soft PVC material, which effectively increases tensile strength and flexibility. It has long service life, stable video transmission model and high definition. It is mainly used for TV monitoring special wire with elevator, including video cable, power cable and steel wire.


The elevator traveling flat cable is a self-supporting flat composite elevator monitoring special cable. The cable combines the video coaxial cable, the power cable, the data cable and the steel strand to form a flat ribbon cable ( TSYV75-5+TVVB2X1.0+G), so that the tension of the whole cable is taken up by the steel strand, the tensile strength is very good, and the signal cable is not broken during the operation of the elevator due to gravity. It is mainly suitable for installation in elevator equipment, as a connection line for equipment, and also for elevators and other lifting and similar lifting systems.

The specific use of the elevator cable in the elevator:

1. When the elevator cable is arranged in a line

1) The free use length is greater than 35m;

2) The running speed is greater than 1.6m/s;

Consideration should be given to adding load-bearing components to the cable. The load-bearing components are generally galvanized soft steel wire ropes or fiber ropes such as aramid yarns.

2. When the elevator cable is twisted and twisted

1) The free suspension length is greater than 80m;

2) The running speed is 4.0m/s~10.0 m/s;

Consideration should be given to adding load-bearing components to the cable, which are typically galvanized soft steel wire ropes.

The audio cable

1, telephone line


HYV is a copper core solid polyolefin insulated moisture barrier polyethylene sheathed local communication cable. Common specifications are two cores and four cores, with wire diameters of 0.4 and 0.5 respectively, 0.8 and 1.0 in several areas, and common materials (conductors) are copper clad steel, copper clad aluminum, and all copper. Among them, only the telephone line that uses copper is used to meet the national standard. Commonly used for: communication engineering wiring, connection between indoor telephone communication cable system wiring, backbone lines between voice communication systems, program-controlled switches, telephone, fax and digital telephone.

Typical models are: HYV2x1/0.4 CCS, HYV4x1/0.4 CCS, HYV2x1/0.4 BC, HYV2x1/0.5 BC, HYV4x1/0.4 BC, HYV4x1/0.5 BC, HSYV 2x2x0.5 BC (Note: CCS is copper clad steel, BC is all bronze). Such as HYV2x1/0.4 CCS—HYV is the telephone line English model, 2 is the 2 core, 1/0.4 CCS stands for a single 0.4mm diameter copper-clad steel conductor, and so on, HYV4x1/0.4 BC, of which HYV model, 4 represents The 4-core, 1/0.5 BC represents a single 0.5 mm diameter pure copper conductor. In particular, HSYV 2x2x0.5—“S” stands for twisted pair, 2x2 stands for 2 pairs (4-core) twisted pair, and 0.5 stands for a single 0.5 mm diameter conductor.

2, audio cable

An audio cable, referred to as an audio cable, is used to spread the sound. The sound quality of the sound line on the market is mainly made of gold, silver and oxygen. Generally used to transmit unamplified audio signals, such as computer, VCD, DVD, radio connected amplifiers. The audio cable is basically not needed for wiring, because the audio source device and the power amplifier are often put together, these lines are very short, and the configuration can be done later.

The main specifications of the audio cable are: audio cable 2 × 0.122, audio cable 71C, audio cable 2 × 0.32

Classification of audio lines:

1) Audio cable: A set of audio cables is often two, divided into left and right channels, and both ends of the line are lotus heads (RCA heads).

2) Coaxial line: used to transmit multi-channel signals (Dolby AC-3 or DTS signals), similar to audio lines, because of the large amount of signals, connectors and lines are thicker than ordinary audio lines, generally used to connect DVD Machine and amplifier.

3) Optical fiber cable: also used to transmit multi-channel signals (Dolby AC-3 or DTS signals) for connecting DVDs

Machine and amplifier.

4) Microphone cable: A two-core coaxial cable for connecting a power amplifier to a microphone.

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