Wire and cable: wire products used for transmitting (magnetic) energy and information and realizing electromagnetic energy conversion.
The difference between wire and cable
There is no strict boundary between "wire" and "cable" in concept. In a narrow sense, it is divided into "wires" and "cables", and in a broad sense, it is collectively called "cables". It is widely believed that:
(1) A single root is called a "line"; Many are called "cables".
(2) The small diameter is called "line"; The larger diameter is called "cable".
(3) Simple structure is called "line"; This complex structure is called "cable".
However, with the expansion of the scope of use, many varieties are "cable in line" and "cable in cable". So there is no need to make a strict distinction. In daily habits, people refer to household wiring as wires and power cables as cables.
Wires and cables mainly include bare wires, winding wires, power cables, communication cables and optical cables, and electrical equipment.
Nomenclature of wires and cables
The complete naming of wires and cables is usually complicated, so people sometimes replace the complete name with a simple name (usually the name of a category) combined with model specifications. For example, "low voltage cable" represents all plastic insulated power cables of 0.6/ 1kV class.
The type spectrum of wires and cables is relatively perfect. It can be said that as long as the standard model specifications of wires and cables are written, a specific product can be defined, but what is its complete name?
Naming principle
The naming of wire and cable products has the following principles:
1. What is included in the product name.
(1) Product application name or size grade
(2) Material or type of product structure;
(3) Important features or additional features of the product
Basically, they are all named in the above order. Sometimes, in order to emphasize important or additional features, features are written before or before the corresponding structural description.
2. The order of the structure description
The product structure is described according to the principle from the inside out: conductor-> conductor; Insulation->; Inner sheath->; External sheath->; Armor type.
simplify
In order not to cause confusion, some structural descriptions are omitted or abbreviated. For example, aluminum conductors are not allowed to be used in automobile wires and flexible cords, so conductor materials are not described.
Case:
Rated voltage 8.7/ 15kV flame retardant copper core XLPE insulated steel belt armored PVC sheathed power cable (too long! )
"Rated voltage 8.7/15kV"-application/voltage level
"Flame-retardant"-the characteristic of emphasis
"copper core"-conductor material
"XLPE insulation"-insulating material
"Steel Strip Armor"-material and type of armor layer (double steel strip gap packaging)
"PVC sheath"-inner and outer sheath materials (the inner sheath material is omitted) "Power cable"-product category name.
The corresponding model is written as Zr-YJV22-8.7/ 15, and the model description is as follows.
Model description
The model composition and sequence of wires and cables are as follows:
[1: category and use ][2: conductor ][3: insulation ][4: inner sheath ][5: structural features ][6: outer sheath or derivative ]-[7: use features]
Items 1-5 and 7 are represented by pinyin letters, and polymer materials are represented by English initials, and each item can be 1-2 letters; Item 6 is the number of 1-3.
Ellipsis principle in the model: copper is the main conductor material used in wire and cable products, so the copper core code T is omitted, except bare wire and bare conductor products. Bare wires and bare conductor products, power cables and electromagnetic wires are not marked with large-scale codes, and wires and cables for electrical equipment and communication cables are not marked with large-scale codes, only small-scale or series codes are listed. Item 7 is the identification of various special use occasions or additional special use requirements, which is marked with pinyin letters after "-". Sometimes in order to highlight this item, write this item at the front. Such as ZR- (flame retardant), NH- (flame retardant), WDZ- (low smoke and no halogen, enterprise standard), -TH (used in hot and humid areas), FY- (termite prevention, enterprise standard) and so on. Digital marking armor outer sheath or outer sheath 0 no-1 interlocking armored optical fiber outer sheath 2 double-layer steel tape PVC outer sheath 3 thin round steel wire polyethylene outer sheath 4 thick round steel wire 5 corrugated (embossed) steel tape 6 double aluminum (or aluminum alloy) tape 8 copper wire weaving 9 steel wire weaving.
Model composition and sequential application of wire and cable
The model composition and sequence of wires and cables [1] are as follows [1: category and use ][2: conductor ][3: insulation ][4: inner sheath ][5: structural features ][6: outer sheath or derivative ]-[7: use features] 1. Item 6 is the number of 1-3. Ellipsis principle in the model: copper is the main conductor material used in wire and cable products, so the copper core code T is omitted, except bare wire and bare conductor products. Bare wires and bare conductor products, power cables and electromagnetic wires are not marked with large-scale codes, and wires and cables for electrical equipment and communication cables are not marked with large-scale codes, only small-scale or series codes are listed. Item 7 is the identification of various special use occasions or additional special use requirements, which is marked with pinyin letters after "-". Sometimes in order to highlight this item, write this item at the front. Such as ZR- (flame retardant), NH- (flame retardant), WDZ- (low smoke and no halogen, enterprise standard), -TH (used in hot and humid areas), FY- (termite prevention, enterprise standard) and so on. Digital marking armor layer outer sheath or outer sheath 0 no-1 interlocking armored optical fiber outer sheath 2 double-layer steel tape PVC outer sheath 3 thin round steel wire polyethylene outer sheath 4 thick round steel wire 5 corrugated (embossed) steel tape 6 double aluminum (or aluminum alloy) tape 8 copper wire weaving 9 steel wire weaving.
The applications of wires and cables are mainly divided into three categories.
1, power system
The wire and cable products used in the power system mainly include overhead bare wires, buses (bus bars), power cables (plastic cables, oil-paper power cables (basically replaced by plastic power cables), rubber cables and overhead insulated cables), branch cables (replacing some buses), electromagnetic wires and wires and cables for electrical equipment.
2. Information transmission system
The wires and cables used in the information transmission system mainly include local telephone cables, television cables, electronic cables, radio frequency cables, optical cables, data cables, electromagnetic cables, power communication or other composite cables.
3, mechanical equipment, instrument system
This part is applicable to almost all other products except overhead bare wires, but mainly power cables, electromagnetic wires, data cables, instrument cables and so on.
Basic categories of products
Wire and cable products are mainly divided into five categories:
1, bare wires and bare conductor products; The main characteristics of this kind of products are: pure conductor metal, without insulation and sheath, such as steel-core aluminum stranded wire, copper-aluminum bus, electric locomotive wire and so on. The processing technology is mainly pressure processing, such as melting, calendering, stretching, twisting/compression twisting, etc. Products are mainly used in suburbs, rural areas, main lines of users, switch cabinets and so on.
2. Power cables; The main features of this kind of products are: extruding (winding) insulation layer outside the conductor, such as overhead insulated cable, or twisting several cores (corresponding to the phase, neutral and ground wires of power system), such as overhead insulated cable with more than two cores, or adding sheath layer, such as plastic/rubber sheath line 4.
Wires and cables. The main technologies include drawing, winding, insulation extrusion (winding), cabling, armoring, sheath extrusion and so on. There are some differences in different process combinations of various products. Products are mainly used for the transmission of high-voltage electric energy in power generation, distribution, transmission, substation and power supply lines, with large current (tens of amperes to thousands of amperes) and high voltage (220V to 500kV and above).
3. Wires and cables for electrical equipment; The main characteristics of this kind of products are: many varieties and specifications, wide application range, and the application voltage is mostly 1kV and below. Facing special occasions, new products are constantly derived, such as fire-resistant cables, flame-retardant cables, wdz/wdz, termite-proof cables, rat-proof cables, oil-resistant/cold-resistant/temperature-resistant/wear-resistant cables, medical/agricultural/mining cables, thin-walled wires and so on.
4. Communication Cable and Optical Fiber (Introduction) With the rapid development of the communication industry in recent twenty years, the products have also developed at an amazing speed. From simple telephone and telegraph cables in the past to thousands of pairs of telephone cables, coaxial cables, optical cables, data cables and even combined communication cables. This kind of products usually have small and uniform structural dimensions and require high manufacturing accuracy.
5. Electromagnetic wires (winding wires) are mainly used in various motors, instruments and meters, etc.
A derivative/new product of wire and cable
Derivative/new products of wires and cables are mainly produced due to different application occasions, application requirements, equipment convenience and equipment cost reduction, adopting new and special materials, changing product structure, improving process requirements, or combining different kinds of products. Use different materials such as flame-retardant cable, low-smoke halogen-free/wdz, termite-proof cable, rat-proof cable, oil-resistant/cold-resistant/temperature-resistant cable. Change the product structure, such as fire-resistant cables; Improve process requirements, such as medical cables and other combined products, such as other, which are easy to install and reduce equipment costs, such as prefabricated branch cables. For example, high-temperature wires and cables are needed in aerospace, rolling stock, energy, steel, non-ferrous metal smelting, oil exploitation, motor and other fields. At present, the commonly used high-temperature wires and cables with long-term continuous working temperatures of 125℃, 135℃, 150℃, 180℃, 200℃, 250℃ and above include irradiated crosslinked polyolefin, silicone rubber, fluororesin, polyimide, mica.
Now introduce; Two new types of high temperature cables.
1. Polyether sulfone (PES) insulated wire has excellent heat resistance, physical and mechanical properties, electrical insulation and extrusion formability, especially it can be used continuously at high temperature, and it can maintain stable performance in the environment with rapid temperature change: the thermal deformation temperature is 200-220 degrees, the continuous use temperature is 180-200 degrees, and the UL temperature index is 65430. Resistant to 150- 160 degree hot water or steam, and not corroded by acid and alkali at high temperature; The elastic modulus is almost unchanged at-100-200 degrees, especially above 100 degrees, which is superior to any thermoplastic resin; The linear expansion coefficient is small, and its temperature dependence is also small; Non-toxic, FDA approved, and also meets the requirements of Announcement No.434 and Announcement No.0/78 of Japanese Ministry of Health and Welfare. It is self-extinguishing, does not add any flame retardant, and has excellent flame retardancy, reaching UL94V-0 grade (0.46mm).
2.PEEK insulated wire PEEK is a super heat-resistant thermoplastic resin. Long-term continuous use temperature of 250 degrees, UL temperature index of 250 degrees. & ltBR & gtPEEK is a flexible resin with good creep resistance. And it's self-extinguishing Without any flame retardant, the requirements of UL94V- 1 (thickness 0.3mm), 94V-0 (thickness 1.5mm) and 94V-5 (thickness 3.2mm) can be met. At present, the price of nonferrous metals in copper-clad aluminum wires and cables has soared, and the cost of copper conductor accounts for more than 90% of the total cost of cable materials. In order to meet the technical index of copper conductor of cable and greatly reduce the cost of cable, Shenghua Group Co., Ltd. independently developed new copper-clad aluminum material technology according to the market demand and relying on the strong scientific and technological strength of the group, and applied it to the wire and cable industry, and formulated enterprise standards. The products have passed the inspection of the National Wire and Cable Quality Supervision and Inspection Center. And after many users try it out, it has won unanimous praise from experts and users. At present, we are actively expanding the production scale to meet the market demand. Scope of application: PVC insulated cables with rated voltage of 450/750V and below and power cables with rated voltage of 30KV and below are suitable for the fixed laying of lighting and power devices with rated AC voltage of 450/750V and below, and power transmission and distribution systems with rated AC voltage of 30KV and below are used for power transmission and distribution. Widely used in electric power, construction, mining, metallurgy, petrochemical, transportation and other departments. The main features of the product ⊙ good corrosion resistance, low contact resistance of conductor ⊙ good weldability. Copper-clad aluminum wire has the same weldability as pure copper wire because its surface is covered with pure copper. ⊙ Light weight, soft thread, easy processing, easy installation and transportation. The copper-clad aluminum material has the advantages of relatively low cost and relatively stable price, and overcomes the shortcomings of high cost and ups and downs of copper materials. Compared with pure copper wire, it has the advantages of copper wire. Under the same DC resistance as pure copper wire, its AC resistance is 2%-5% larger than that of copper wire (the larger the cross-sectional area, the more obvious the effect).
Brief introduction of quality appraisal
Wires and cables are indispensable materials for users to use electricity, and their quality is directly related to the safety of thousands of households. Therefore, how to quickly and accurately check the quality of electric wires (compensation wires, compensation cables, shielded compensation wires, shielded compensation wires, high-temperature compensation wires, computer shielded cables, K-type compensation wires, S-type compensation wires and other wires and cables) is a skill that most electricians must master. When buying wires, you should buy them in regular shopping malls, and look for the national electrician certification mark (Great Wall pattern) and the trademarks, specifications and voltages printed on the wires.
standard
1. Wire rods with good weight and quality are generally within the specified weight range.
2. The copper core of qualified copper core wire should be purple, shiny and soft to the touch. False copper core wire is purple-black, yellow or white, with many impurities and poor mechanical strength and toughness. It will break with a little force, often breaking wires. When checking, just peel off one end of the wire by 2cm, and then gently rub it on the copper core with a piece of white paper. If there is a black substance on the white paper, it means that there are many impurities in the copper core. In addition, the insulation of fake and inferior wires seems to be very thick. In fact, most of them are made of recycled plastics. Over time, the insulation layer will age and leak electricity.
3. Manufacturers' fake and shoddy wires are often "three no products", but there are also vague labels on them, such as those made in China and some provinces and cities in China. Is actually equal to the unmarked origin.
4. Price Because the production cost of fake and inferior wires is low, vendors often sell them at low prices under the guise of good quality and low price, which makes people fall for it.
Misunderstanding of wire and cable use
First, covet the cheapness of wires and cables.
This is a common misunderstanding that quite a few users and even some enterprises use wires and cables. In order to save money and ignore safety, some users specially select inferior wires and cables with low price, unreliable quality and great accident potential. We know that due to the safety of wires and cables, the price of wires and cables can not meet the requirements of some users. However, some individual and private enterprises cannot manufacture wires and cables that meet the requirements of national standards in terms of material selection, production technology and testing methods, and their safety will not be guaranteed. In addition, making a fuss about short feet and short meters will flood the market with its low price and cater to some users. Therefore, users are advised not to covet cheap wires and cables.
Second, improper modeling of wires and cables.
Some users don't know enough about their own electrical requirements and environmental conditions, and don't know enough about the application scope, requirements and performance of wire and cable models, so they often choose the wrong model. For example, the power of the slag truck in front of the steelmaking plant is a motor, and the temperature in front of the furnace is as high as 800℃ ~ 900℃. Under such environmental conditions, because the factory knows nothing about the special requirements of wires and cables, the general rubber-sheathed flexible cable is selected for YC charging, which leads to short service time and charred sheath, which not only affects production, but also wastes economy. After negotiation, the fire-resistant and flame-retardant cable was selected, which reduced the pain and economic loss of replacing the cable and ensured the normal production of the enterprise. Some important departments, high-rise buildings, computing centers, chemical industry, public entertainment places and places where people are concentrated should use flame-retardant or fire-resistant cables with fire-fighting function; The Ministry of Coal stipulates that cables used in deep wells of coal mines must be flame retardant; There are also elevator cables, welding machine cables, motor leads and so on. They all have special performance requirements. In actual use, some enterprises, especially individual enterprises, often don't know enough about these special wires and cables with special requirements and refuse to use them. Some enterprises ignore the requirements of the Ministry of Coal that cables for deep wells in coal mines must be flame retardant, but buy ordinary rubber-sheathed flexible cables; There are also some karaoke bars and places where people are concentrated, and some general wires and cables without fire fighting function are installed, which has caused great hidden dangers of accidents.