Cable Encyclopedia

Take you to understand 5052 H34 aluminium sheet

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This article will take you to understand 5052 aluminium sheet

5052 H34 aluminium sheet is a kind of aluminium alloy. It has the composition of 50% Aluminium and balance with other elements, such as Copper, Magnesium, Silicon and so on. The alloy is mainly used for the production of aircrafts and cars.

Aluminum is one of the most important metals in our daily life. It can be used in many different ways to make products that are useful for us. Aluminum sheets are made by rolling aluminum ingots into thin sheets that are then cut into various shapes or sizes to fit specific uses or purposes. These sheets can be used in many different ways, such as for building structures, making utensils and appliances, or even for decorative purposes.

Take you to understand 5052 H34 aluminium sheet

5052 H34 aluminium sheet is a very strong metal that can be used to make products that are durable and long lasting. It is also lightweight so it does not add much weight to the product it is used on. This makes it easy to transport from one place to another without having to worry about the weight of the product. Aluminum sheets are also resistant against corrosion so they can last a very long time without deteriorating or losing their strength.

Another advantage of using aluminum sheets instead of other metals is that they are easy to work with. They can be cut, punched and formed into any shape or form that you want. This makes them very versatile and easy to use in many different ways.

The main disadvantage of using aluminum sheets instead of other metals is that they are not as strong as some other types of metal. This means that the product made out of aluminum may not last as long or hold up against harsh conditions as well as products made from stronger metals would do. However, this is a minor disadvantage because most products today are built to last only for a short t period of time.

Aluminum alloy Cable in wind farm

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In recent years, China’s wind power industry has been developing rapidly, and the total installed capacity and annual new installed capacity of wind power are in the forefront of the world. However, due to the harsh environmental conditions of wind farms, the cable terminals, cable bodies, etc. of the power collection lines in the site are prone to failure, so it is necessary to constantly use new materials and processes with advanced technology and reliable performance to improve the operation quality of the power collection lines for the safe and stable operation of wind farms.

The power cable is an important part of the collection line of the wind farm. Generally, there are two types of cable conductors for the wind farm: aluminum core and copper core. Aluminum core cable and copper core cable have their own shortcomings. The disadvantage of aluminum core cable is poor flexibility, and it is easy to break after repeated bending; Poor stability, easy to be corroded and oxidized; High resistivity, high energy consumption and large loss compared with copper cores of the same section; Poor ductility, inconvenient installation, etc. The disadvantage of copper core cable is its high price; Heavy weight; High construction and transportation costs.

Based on the above situation, domestic cable manufacturers have started to produce aluminum alloy cables. At present, there are more than 10 domestic enterprises producing aluminum alloy cables. In fact, as early as 1968, the American Southern Cable Company invented aluminum alloy cable. The United States, Canada and other countries have had more than 40 years of application history. Therefore, it is necessary to analyze the use of aluminum alloy cable products in order to improve the operation quality of the collection line of the wind farm and reduce the project cost.

 

Analysis of Characteristics of Aluminum Alloy Cable

The main components of the conductor of aluminum alloy cable are: copper, iron, silicon, magnesium, manganese, titanium, chromium, zinc, rare earth, etc. The role of copper increases the resistance stability of the conductor at high temperatures; The role of iron is to increase the creep resistance of conductor; The function of magnesium is to improve the tensile strength of conductor; The function of rare earth is to improve the corrosion resistance of conductor. 5083 aluminum alloy plate is also widely used in wind power generation and can be used as the pedal of wind tower

 

1、 Electrical performance of aluminum alloy cable

（1） Conductivity: The conductivity of aluminum alloy is between aluminum and copper, inferior to copper and slightly superior to aluminum.

（2） Cable compression characteristics: aluminum alloy conductor adopts layered compression stranding technology, and the compression coefficient of conductor can reach 0.93, while the compression coefficient of copper conductor is generally only 0.80. The maximum limit compaction can make up for the shortage of aluminum alloy conductor in volume conductivity, so that the stranded conductor core is like a solid core, which significantly reduces the outer diameter of the core and improves the conductivity. Therefore, when the ampacity is the same, the outer diameter of the cable after aluminum alloy cable replaces the copper core cable does not increase much.

 

2、 Mechanical properties of aluminum alloy cables

The elongation of hard pure aluminum is very low, and it is easy to be damaged or broken during repeated bending. The elongation of soft pure aluminum is much higher than that of hard pure aluminum, but its yield strength is only half that of copper, and its creep resistance is poor. After installation for a period of time, the connection is easy to relax, resulting in increased contact resistance, forming a hidden danger for safe operation. Through the comparison in Table 1, it can be concluded that the mechanical properties of aluminum alloy conductor have the following advantages:

（1） High extension. The elongation of aluminum alloy conductor after annealing can reach 30%, which is close to copper but much higher than aluminum. This also shows that aluminum alloy conductor can withstand greater external forces than aluminum conductor.

（2） Strong and flexible, easy to bend. During installation, aluminum alloy conductor has smaller bending radius than aluminum conductor, which makes it easier to connect terminal blocks.

（3） Good creep resistance. The creep resistance and compactness of the alloy elements in aluminum alloy have been greatly improved after special process treatment. When the conductor encounters extreme conditions such as cold flow, overload and overheating, stable connection can also be ensured.

 

3、 Corrosion resistance of aluminum alloy cable

The rare metals added in the aluminum alloy conductor further improve the corrosion resistance of metal materials with aluminum as the conductor in terms of chemical properties, and reduce the potential difference between different metals. The smaller the potential difference, the lighter the corrosion will be. The rare earth elements in alloy materials can play a role in filling surface defects, refining grains, and eliminating local corrosion of conductors. At the same time, they also bring negative electrode potential shift of aluminum, which has an anodic effect, thus greatly improving the corrosion resistance.

 

4、 Economic performance of aluminum alloy cable

Compared with copper cable, the price advantage of aluminum alloy cable is also obvious. The price of aluminum alloy cable with the same ampacity is only 60% – 70% of that of copper cable. In addition, due to the light weight, the installation cost is indirectly reduced.

Selection of 35kV cable conductor in wind farm

For 35kV high-voltage cables used in the wind farm, in order to save the project cost, aluminum core is preferred as the conductor. On the premise of meeting the voltage drop and the corrected ampacity, the economic current density is used to calculate the appropriate cable cross-section.

With the increase in the number of wind farms and the passage of operation time, the disadvantages of aluminum core cables gradually emerge, mainly in the following aspects:

1、 Poor mechanical strength, easy to break. The area where the wind farm is located is in a harsh environment with high wind speed, and the wind load on the cable after it is mounted on the tower is large. In particular, due to the influence of umbrella groups, the wind surface at the cable terminal is larger, so it is easier to have failures. The connection of cable and wire is shown in Figure 1.

2、 The creep resistance is poor. After the wind farm cable is installed on the tower, when the current passing through the conductor is too large, the aluminum conductor will become hot and creep, and the cable joint is easy to become loose and deformed, resulting in poor line contact, which will cause line and equipment failure accidents.

3、 High resistivity and high loss. The cable conductor section is selected for the wind farm. The aluminum core section is much larger than the copper core section. For example, if the cable section is too large and the cable length far exceeds the maximum production reel length of the cable manufacturer, the number of cable sections and intermediate joints will increase, which is unfavorable for the long-term operation of the collector line.

Based on the above reasons, the power cables in wind farms in recent years mainly use copper cores. Copper core cables can solve various problems of aluminum core cables. However, in recent years, China’s demand for copper materials has gradually increased, and copper prices have also been rising, which has virtually increased the cost of many projects and increased the risk of stolen cables at the construction site. In addition, due to the heavy weight of copper core cables, the requirements for cable supports are also high.

Compared with aluminum core and copper core cables, aluminum alloy cables do have many advantages and can replace them in many occasions. In addition, aluminum alloy conductors have been added to the GB/T3956-2008 Conductor of Cables. Therefore, it is theoretically feasible to use aluminum alloy cables in the collection lines of wind farms.

However, there are still some problems to be solved in the massive promotion of aluminum alloy cables in wind farms:

Aluminum alloy conductors have various models according to the chemical composition added, but there is no description of the added chemical composition in the domestic specifications, so the products are easy to be different in bidding and actual supply.

Due to the different expansion coefficients of aluminum alloy, aluminum and copper conductors, different conductors should not be directly connected. Transition terminals are required to ensure the reliability of the connection between aluminum alloy conductors and copper and aluminum conductors, which increases the risk of use.

There are few application cases of aluminum alloy cables used in wind farms. Whether aluminum alloy cables are more reliable than aluminum core and copper core cables in applications in special areas such as high temperature, cold, high altitude, high salt spray, and high temperature difference also requires time to test.

 

Epilogue

After the above analysis, aluminum alloy cable has good conductivity and excellent mechanical properties, which improves the unreliable connection, poor mechanical properties and easy creep of aluminum core cable. However, considering that there are still some problems of aluminum alloy cables that need to be improved and solved, it is suggested that the wind farm should try out aluminum alloy cables in a part of the collector line or in a certain transmission circuit according to the site conditions, especially in the technical transformation of the early wind farm. Through comparison under the same operating environment, we can know whether its line loss, failure rate and other aspects are better than copper core and aluminum core cables, It will provide practical experience for future promotion.

We have reason to believe that the use of aluminum alloy cables in specific occasions is the development trend of the cable industry in the future after time inspection and gradual improvement of relevant regulations and specifications.

Climb aluminum was used in Beijing APEC Conference Building

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Climb aluminum was used in Beijing APEC Conference Building

The Yanqi Lake “National Conference Center” project in Huairou, Beijing, as the venue of the 2014 APEC Conference, has attracted worldwide attention. The building base area of the project is 14,000 square meters, and the building area is 41,900 square meters. It is mainly a unit curtain wall structure. All curtain walls, doors and windows of the project are made of Climb aluminum.

As the most influential official forum for economic cooperation in the Asia Pacific region, the 2014 APEC Conference was held in Beijing. During the meeting cycle, there will also be APEC Business Leaders Summit, dialogue between APEC leaders and representatives of the Business Advisory Council and other business activities and leaders’ spouse activities. It was held in China 13 years after the 2001 Shanghai APEC Conference, which is of great significance.

Climb aluminum was used in Beijing APEC Conference Building

In recent years, with excellent quality and service, “Climb” brand aluminum plates have been used at the new site of CCTV Building, the New Capital Airport, the U.S. Embassy in China, the General Administration of Customs, the Chinese National Theatre, the State Environmental Protection Administration, the National Museum, the venues for the 2008 Beijing Olympic Games, the 2009 National Games, the 2010 Shanghai World Expo, the 2012 Asian Beach Games The 2013 Jinzhou World Horticultural Exposition has been widely used in the construction of venues. It is also exported to Asia, Africa, the United States, Europe and Oceania, and exported to more than 40 countries and regions such as the United States, France, Britain, Russia, South Korea, Japan and Denmark.

Basic characteristics of aviation aluminum alloy

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The main characteristics of aluminum alloys for aerospace are: large-scale and integration, thin-walled and lightweight, precision of section size and geometric tolerance, uniformity and quality of microstructure and properties. According to different service conditions and parts of aircraft, aluminum alloys for aerospace are mainly high-strength aluminum alloy, heat-resistant aluminium alloy and corrosion-resistant aluminum alloy. High strength aluminum alloy is mainly used for aircraft fuselage components, engine compartment, seats, control systems, etc., and is the most widely used,For example, 5086 aluminum alloy.

characteristics of aviation aluminum alloy

The biggest characteristic of aviation aluminum alloy is that it can improve the strength by deformation heat treatment. Deformation heat treatment is a comprehensive process that combines the deformation strengthening of plastic deformation with the phase transformation strengthening during heat treatment to unify the forming process and formability. During the plastic deformation process of aviation aluminum alloy, the defect density inside the crystal increases, and these crystal defects will cause the change of the internal microstructure of the material. In the process of plastic deformation of aviation aluminum alloy, dynamic recovery, dynamic recrystallization, sub dynamic crystallization, static recrystallization, static recovery and other crystal structure changes will occur. These changes in crystal structure, if properly controlled, will significantly improve the mechanical properties of the material and enhance the service life of the material.

Aeronautical aluminum alloys are generally strengthened by precipitation of dispersed phase in supersaturated solid solution. The general precipitation sequence is: segregation region (or GP region) ~ transition phase (metastable phase) ~ equilibrium phase. In the process of deformation heat treatment, deformation induces precipitation, precipitation affects deformation, deformation and precipitation affect each other, and dynamically affect the properties of the material.

characteristics of aviation aluminium alloy

The precipitation strengthening process of deformation heat treatment is greatly affected by temperature. Deformation heat treatment can be divided into high temperature deformation heat treatment and low temperature deformation heat treatment. The basic processes of low temperature deformation heat treatment are: quenching of aviation aluminum alloy, cold deformation at room temperature and aging heat treatment. After this treatment, the strength of aviation aluminum alloy is greatly improved, but the plasticity is reduced. High temperature deformation heat treatment process: quenching, high temperature deformation and aging. After high temperature deformation heat treatment, the strength of the material is higher, the plasticity and toughness are improved, and the heat resistance strength of the alloy is also improved.

What are the commonly used low-voltage power cables?

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(1) Classification of low-voltage power cables
Low-voltage power cables are generally divided into polyvinyl chloride insulated (plastic) power cables, XLPE insulated power cables, rubber insulated power cables, oil-filled and oil-impregnated paper insulated power cables according to their insulation types, and can be divided according to their work types and properties. It is a type of general ordinary power cable, overhead power cable, mine underground power cable, submarine power cable, fire-resistant (fire-resistant) flame-retardant power cable, etc.
(2) Several commonly used low-voltage power cables and their characteristics
1. Copper core conductor power cable
At present, all low-voltage power cables in China are twisted together by each core wire. The cable with this structure has poor anti-interference ability and poor lightning resistance performance. The three-phase impedance of the cable is unbalanced and the zero-sequence impedance is large, which makes it difficult to protect the line. Electrical appliances operate reliably, etc. The copper and aluminum PVC copper core conductor power cables with rated voltages of 0.6kv ~ 1kv

2. XLPE insulated power cable
Referred to as XLPE cable, it uses chemical or physical methods to change the molecules of the cable’s insulating material polyethylene plastic from a linear structure to a three-dimensional network structure, that is, to convert the original thermoplastic polyethylene into a thermosetting cross-linked polyethylene. Plastic, which greatly improves the heat resistance and service life of the cable, and still maintains its excellent electrical properties.
3. PVC insulated PVC sheathed power cable
The long-term working temperature of PVC insulated and PVC sheathed power cables does not exceed 70 °C, and the maximum temperature of the cable conductor does not exceed 160 °C. The longest duration of short circuit shall not exceed 5s, and the minimum temperature of construction and laying shall not be lower than 0℃.

XLPE insulated cable eccentricity control details

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1. Wire drawing and twisting
Qualified products are not detected, but manufactured. For the control of 110kv cable eccentricity, each department in the cable enterprise has corresponding quality control responsibilities. Here we mainly talk about the understanding and detailed control of conductor preparation and tooling level. When designing a conductor, people give priority to or often only consider the reference conductor carrying capacity and conductor DC resistance. This is not enough for 110kv and above power cables. The roundness and straightness of the conductor often affect the XLPE insulation material. Distribution, which in turn affects the electric field distribution in the cable; the monofilament ductility of the conductor filaments will affect the cable insulation stress; the conductor surface quality (such as oxidation caused by improper storage, conductor knocks in the disk flow, etc.) on the current carrying capacity Wait. In the process of drawing, if the concentration and temperature of the emulsion are not regularly checked and replaced according to the standard, it is very likely that the monofilament will be oxidized in the drawing. In the conductor stranding process, the conductor protection is insufficient. Some companies have installed online DC resistance measuring instruments but do not use them. Some companies produce high-voltage cables according to the habit of producing low- and medium-voltage cables, even when they are producing 110kv cables because of the absence of staff on duty. , The personnel are transferred from the production line of low-voltage cables. These ideological understanding and detailed control will seriously affect the eccentricity control of the cable, but they are often ignored due to people’s experience. Uneven cable field strength distribution caused by scratches is an undesirable result.

2. Preservation and scientific use of insulating materials (including insulation, conductor shielding, and insulating shielding)
The transportation, storage and use of 110kv XLPE insulation material have strict requirements. The XLPE transportation link is not controlled by the cable company but is controlled by the cable material supplier. However, the cable company should also put forward corresponding requirements. The climate in the south is humid (install indoor temperature control equipment, balance humidity and temperature, and store cable materials at room temperature) and so on. When cable companies store XLPE cable materials, they should make unified arrangements and establish special insulation materials and shielding materials storage rooms to prevent material deterioration or abnormalities caused by climate change. There are only a handful of cable material companies in China that produce 110kv and above. Most of the ultra-high voltage XLPE insulation materials are imported from Borealis, Dow Chemical and other foreign companies. Due to language differences, most of the materials’ certificates are in English, and there is no Obvious production date and shelf life identification, using codes or codes that only cable material manufacturers can understand, this brings great inconvenience to cable material users. When the cable material is used in batches, the most contacted cable material is Workshop operators rarely understand English. The author had previously suggested a cable material foreign company, but only got a vague answer. This is because UHV cable materials belong to the seller’s market and are monopolized by a few companies. It is recommended that domestic cable companies must clarify the transportation conditions, production date, shelf life and Chinese-English bilingual instructions when purchasing UHV cable materials. In addition, XLPE insulation, shielding material storage rooms and inter-connection operation rooms should be prohibited from entering and exiting non-duty operators as much as possible. When there are special circumstances, dust removal work must be done to avoid cable breakdown due to a strand of hair. If conditions permit, companies can install monitors in the storage room to increase assessment efforts so that all employees can realize the huge impact of high-voltage and ultra-high-voltage insulation materials on cables.
3. Process technology
The XLPE insulated cable cross-linking production line in the cable industry in the world basically has two methods: catenary and tower. In recent years, the discussion of which is better for catenary and tower has been going on. According to public information, if China Nearly 60 vertical towers have all cross-linked lines in full production, which can meet the world’s demand for high-voltage and ultra-high-voltage cables. Therefore, the 21st order of the Development and Reform Commission in 2013 on the addition of 6KV and above dry-type cross-linking production lines to the cable industry limits.
The technical factors that affect the eccentricity of the cable insulation also include: the specifications of the extrusion die, the stress of the XLPE insulating material, the operating temperature and speed of the cross-line, the skill level of the operators, and so on.For more cable knowledge, please follow Chris’s cable.

Types of cables for photovoltaic power generation systems

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Photovoltaic special cables, power cables, control cables, communication cables, radio frequency cables
Photovoltaic cable: PV1-F1*4mm2
The cable from the string to the combiner box is generally used: photovoltaic special cable PV1-F1*4mm2.
Features: The photovoltaic cable has a simple structure. The polyolefin insulation material used in it has excellent heat resistance, cold resistance, oil resistance, and ultraviolet resistance. It can be used under harsh environmental conditions and has a certain mechanical strength.
Laying: It can be protected through the pipe, and the component bracket is used as the channel and fixing of the cable laying to reduce the impact of environmental factors.
Power cable: ZRC-YJV22
Steel tape armored flame-retardant cross-linked cable ZRC-YJV22 is widely used in: combiner box to DC cabinet, DC cabinet to inverter, inverter to transformer, transformer to power distribution device, power distribution device to the power grid connecting cables.
The common nominal cross-sections of ZRC-YJV22 cables in photovoltaic power generation systems are: 2.5mm2, 4mm2, 6mm2, 10mm2, 16mm2, 25mm2, 35mm2, 50mm2, 70mm2, 95mm2, 120mm2, 150mm2, 185mm2, 240mm2, 300mm2.


Features:
(1) The texture is hard, the temperature resistance grade is 90°C, it is easy to use, has the characteristics of low dielectric loss, chemical corrosion resistance and no drop limit for laying.
(2) It has high mechanical strength, good resistance to environmental stress, good thermal aging performance and electrical performance.
Laying: It can be buried directly, suitable for fixed laying, and adapt to the needs of different laying environments (underground, water, trenches and tunnels).
Power cable: NH-VV
NH-VV copper core PVC insulated PVC sheathed fire-resistant power cable. Suitable for rated voltage 0.6/1KV.
Use characteristics: Long-term allowable working temperature is 80°C. Allowable bending radius during laying: single-core cables are not less than 20 times the cable outer diameter, and multi-core cables are not less than 12 times the cable outer diameter. When the cable is laid, the ambient temperature is not lower than 0 degrees Celsius, without pre-heating. The voltage laying is not limited by the drop.
Laying: Suitable for occasions with fire resistance requirements, and can be laid indoors, in tunnels and trenches. Note that it cannot withstand the action of external mechanical forces and can be directly buried in the ground.


Control cable: ZRC-KVVP
ZRC-KVVP copper core PVC insulated PVC sheathed braided shielded control cable. It is suitable for the control, monitoring circuit and protection circuit of AC rated voltage 450/750V and below.
Features: Long-term allowable use temperature is 70℃. The minimum bending radius is not less than 6 times the outer diameter.
Laying: Generally, it is laid indoors, cable trenches, pipes and other fixed places that require shielding and flame retardancy.
Communication cable: DJYVRP2-22
DJYVRP2-22 polyethylene insulated PVC sheathed copper wire braided shielded armored computer special soft cable is suitable for electronic computers and automation connection cables with high requirements for interference prevention at rated voltages of 500V and below.
Features: DJYVRP2-22 cable has the characteristics of oxidation resistance, high insulation resistance, good withstand voltage, and low dielectric coefficient. While ensuring the service life, it can also reduce the crosstalk and external interference between circuits, and the signal transmission quality is high. The minimum bending radius is not less than 12 times the cable outer diameter.
Laying: The cable is allowed to be fixedly laid and used under the ambient temperature of -40℃~50℃. Laying indoors, cable trenches, pipelines and other places that require electrostatic shielding.
Communication cable: RVVP
Copper core PVC insulated PVC sheathed insulated and shielded flexible cable RVVP, also known as electrical connection anti-interference flexible cable, is a communication cable suitable for anti-interference, safe and efficient data transmission, such as alarms and security.
Features: Rated working voltage 3.6/6KV, long-term working temperature of the cable conductor is 90℃, and the minimum allowable bending radius is 6 times the outer diameter of the cable. It is mainly used as a communication cable to play a role in anti-interference. Laying: The RVVP cable should not be exposed to sunlight, and the bottom core must be well grounded. The weak current circuit communication cables that need to suppress the intensity of electrical interference should be laid in steel pipes and boxes. When laying parallel to the power cable, the distance should be kept away as far as possible.
RF cable: SYV
Solid PE insulated and PVC sheathed radio frequency coaxial cable SYV.
Features: The commonly used video cables in monitoring are mainly SYV75-3 and SYV75-5. If you want to transmit video signals within 200 meters, you can use SYV75-3, and if you want to transmit video signals within 350 meters, you can use SYV75-5.
Laying: It can be laid through a pipe.

Small difference between overhead cable and fiber optic cable

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Overhead cable: When the phone converts the acoustic signal into an electrical signal and then transmits it to the switch via the line, the switch transmits the electrical signal directly to the other phone via the line for answering. The transmission line during this conversation is the cable. The main part of the cable is copper core wire. The single core wire diameters are divided into 0.32mm, 0.4mm and 0.5mm. The larger the diameter, the stronger the communication capability; and according to the number of core wires, there are: 5 pairs, 10 pairs, 20 pairs, 50 pairs, 100 pairs, 200 Yes, wait, the logarithm mentioned here refers to the maximum number of users that the cable can accommodate; it is also divided by package.
Optical fiber cable: It is large in size, weight, and poor in communication ability, so it can only be used for short-distance communication. Optical cable: When the phone converts the acoustic signal into an electrical signal and then transmits it to the switch via the line, the switch transmits the electrical signal to the photoelectric conversion device (converts the electrical signal into an optical signal) and transmits it to another photoelectric conversion device via the line ( Convert optical signals into electrical signals), and then to the switching equipment, to another phone to answer. The line between the two photoelectric conversion devices is an optical cable. Gu said that it is only divided by the number of core wires, the number of core wires: 4, 6, 8, 12 pairs and so on.


Optical cable: It has the advantages of small size, weight, low cost, large communication capacity, and strong communication capability. Due to many factors, it is currently only used for long-distance and point-to-point (ie, two switch rooms) communication transmission. Their difference: the inside of the cable is copper core wire; the inside of the optical cable is glass fiber. Optical fiber communication optical cable is a kind of communication line in which a certain number of optical fibers form a cable core in a certain way, and are covered with a sheath, and some are also covered with an outer sheath to realize the transmission of optical signals. Field tests have been carried out successively in Shanghai, Beijing, Wuhan and other places. Soon after, it was tried out as an intermediate trunk in the local telephone network. After 1984, it was gradually used for long-distance lines, and single-mode fiber was adopted. Communication optical cables have greater transmission capacity than copper cables, with long relay sections, small size, light weight, and no electromagnetic interference. Since 1976, they have developed long-distance trunk lines, intra-city relays, offshore and transoceanic submarine communications. , As well as the backbone of wired transmission lines such as local area networks and private networks, and began to develop into the field of user loop distribution networks in the city, providing transmission lines for fiber-to-the-home and broadband integrated service digital networks. The cable is usually a rope-like cable that is twisted by several or several groups of wires (at least two in each group). Each group of wires is insulated from each other and is often twisted around a center. The entire outer bread has a height. Insulating coating; especially the submarine cable first: there is a difference in material. Cables use metal materials (mostly copper and aluminum) as conductors; optical cables use glass fibers as conductors. Second: There is a difference in the transmission signal. The cable transmits electrical signals. Optical cables transmit optical signals. Third: There are differences in the scope of application. Cables are now mostly used for energy transmission and low-end data information transmission (such as telephone). Optical cables are mostly used for data transmission.

What is a photovoltaic cable?

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The construction of cost-effective and profitable photovoltaic power plants represents the most important goal and core competitiveness of all solar manufacturers. In fact, profitability depends not only on the efficiency or high performance of the solar modules themselves, but also on a series of components that seem to have no direct relationship with the modules. For example, if the photovoltaic power station fails to use suitable cables, it will affect the service life of the entire system. So, what is a photovoltaic cable?
Photovoltaic cable is an electron beam cross-linked cable with a rated temperature of 120°C, which is equivalent to 18 years of use under continuous temperature conditions of 90°C; and when the temperature is lower than 90°C, its use Longer life.
The characteristics of photovoltaic cables are determined by their special insulation materials and sheath materials, which are called cross-linked PE. After being irradiated by an irradiation accelerator, the molecular structure of the cable material will change, thereby providing its various performances. During installation and maintenance, the cables can be routed on the sharp edges of the roof structure. At the same time, the cables must withstand pressure, bending, tension, cross tensile loads and strong impacts. If the cable sheath is not strong enough, the cable insulation layer will be severely damaged, which will affect the service life of the entire cable, or cause short-circuit, fire, and personal injury hazards.
Photovoltaic cable selection


The cables used in the low-voltage DC transmission part of the solar photovoltaic power generation system have different requirements for the connection of different components due to different use environments and technical requirements. The overall factors to be considered are: the insulation performance of the cable, the heat-resistant and flame-retardant performance, Engage in aging performance and wire diameter specifications. Specific requirements are as follows:
1. The connecting cable between the solar cell module and the module is generally connected directly with the connecting cable attached to the module junction box. When the length is not enough, a special extension cable can also be used. Depending on the power of the components, this type of connecting cable has three specifications with a cross-sectional area of ​​2.5m㎡, 4.0m㎡, and 6.0m㎡. This type of connecting cable uses a double-layer insulation sheath, which has superior resistance to ultraviolet rays, water, ozone, acid, and salt, as well as superior all-weather capability and abrasion resistance.
2. The connecting cable between the battery and the inverter requires the use of a multi-strand flexible wire that has passed the UL test, and it should be connected as close as possible. Choosing a short and thick cable can reduce the loss of the system, improve efficiency, and enhance reliability.
3. The connecting cables between the battery square array and the controller or DC junction box also require the use of multi-strand flexible wires that have passed the UL test. The cross-sectional area specification is determined by the maximum current output of the square array.
The cross-sectional area of ​​the DC cable of each part is determined according to the following principles: The connecting cable between the solar cell module and the module, the connecting cable between the battery and the battery, and the connecting cable of the AC load. Generally, the rated current of the selected cable is the maximum continuous operation of each cable 1.25 times the current; the connecting cable between the solar cell array and the array, the connecting cable between the battery (group) and the inverter, the cable rated current is generally 1.5 times the maximum continuous working current in each cable.

Production of cables without production license is punished

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From the first batch of “iron fist”, there are cables again and again. There’s nothing to say. We’re catching up with the “quality month”. Xiaobian reminds everyone to pay attention. There will be some later. Don’t forget what we said in the early stage. There will be a reward of 1 million for reporting, so someone must have moved this crooked idea in the near future.
On June 15, 2021, the market supervision bureau of Changchun City, Jilin Province imposed an administrative penalty of confiscating 1000 meters of AAAC Cable involved and imposing a fine of 110000 yuan on Jilin Xinda Cable Co., Ltd. for the illegal act of producing extruded insulated low-voltage power cable without obtaining a production license.


On March 18, 2021, the law enforcement officers of Changchun Market Supervision Bureau inspected the business premises of the parties according to the reporting clues, and found that the parties stored extruded insulated low-voltage power cables (model: wdzcyjlv4) on the site × 400+1 × 240； Voltage 0.6/1kv; Sectional area 400mm ²； Manufacturer: Jilin Xinda Cable Co., Ltd.) with a total of 1000m, and the cross-sectional area exceeds the “cross-sectional area ≤ 300mm” allowed by its production license ²” It is suspected to produce extruded insulated low-voltage ACAR Cables without obtaining production license.


After investigation, the extruded insulated low-voltage power cables of the above specifications and models produced by Jilin Xinda Cable Co., Ltd. belong to the products listed in the production license catalogue, and the party concerned has not obtained the production license of the products of the above specifications and models. After consulting the production accounts, sales accounts and sales invoices provided by the parties, the law enforcement officers found that the parties produced 1000 meters of the above illegal products according to the contract, with a price of 110 yuan / meter and a total value of 110000 yuan. Since the products have not been sold, there are no illegal gains. The act of the party concerned violated the provisions of Article 5 of the regulations of the people’s Republic of China on the administration of production licenses for industrial products, and Changchun Market Supervision Bureau imposed administrative penalties on the party concerned according to law.


Power cables are widely used in people’s production and life. The power cables used have quality problems, which may cause short circuit or aging and fire, and there are serious potential safety hazards. Therefore, the State implements production license management for power cables. Strictly investigating and punishing the production of power cables without production license according to law and further strengthening the supervision and management of ACSR Cable product quality are conducive to improving product quality level, clarifying product quality responsibility, protecting the legitimate rights and interests of consumers and maintaining social and economic order.