Up 80%! Some people “cover” copper not sold

“Do you have a copper machine tool? We can make a home valuation! ” Lao Zhao is a recycling business of scrap metals. Recently, he is circulating recycling advertisements by friends.
After the Spring Festival, copper prices have set a high, recycling manufacturers are looking for scrap copper. Zhao also took the opportunity to make a profit in this wave of market. He said that before the Spring Festival, the price of copper acsr cable was about 40000 yuan per ton, and now it has risen to more than 70000 yuan a ton, or nearly 80 percent.


With the continuous increase of copper price, the raw material cost pressure of downstream metallurgical and processing enterprises is becoming increasingly prominent. In this context, relatively low-cost and environmental protection of waste copper has become “fragrant bun”.
Industry insiders said that the rising copper price and the increase of copper cost are the main reasons for the popularity of recycled copper resources. In the future, the depletion and supply reduction of copper resources abroad will be the trend of the whole world. The market of urban mines and recycled copper resources will have unlimited potential.

01
Downstream telephone burst, waste copper recycling station “cover not sell”

Near a scrap metal recycling station in the suburb of Tanggu, Tianjin, the abandoned copper wires were piled on the roadside, and the sun was golden. Once, this is the “urban waste” that nobody asks for. Nowadays, they are precious renewable resources that enterprises plunder.
In the warehouse built up by color steel plate, Shanghai Securities News reporter saw that the door was a black and abandoned cable, which was randomly collected by several sacks. Walk down the wall, and the white sack behind it is filled with yellow copper cables. The staff said that these are copper wires picked up from the cable at the door. Once, these copper wires were not worth a few money, and now they are worth a lot.

“We have been operating this recycling station for more than ten years, and this year’s good market has hardly seen.” Lao Qin, the head of the recycling station, said that the scrap copper sold only 40000 per ton a ton a ton a year ago, but there was not much downstream goods, and the warehouse was filled with goods that could not be sold. After the Spring Festival, copper and brass cables suddenly became “fragrant bun”, which has exceeded 80000 yuan per ton.
In the past, recyclers were “unreasonable” about copper waste resources, waiting for customers to ask for the recovery price. Now they are starting to drive to factories around the country to find copper scrap valuations.
The copper recovered by Laozhao in Shanghai comes from the abandoned machine tools, cables, copper pots, and parts removed from various old appliances. He took his recycling company for example, in the past, after he recycled and processed it every month, copper sold at most 12000 yuan, and now it can reach more than 100000 yuan per month“ Taking advantage of the high copper prices in recent months, I have shipped all the hoards that I couldn’t sell in the past, making a lot of money net. ”

However, more copper recyclers have a “business experience” and do not rush to sell the accumulated copper to intermediate agents or downstream copper refineries.
“Copper is now priced one day, and the cable copper, which was once slow to sell after the Spring Festival, is almost double.” Old Meng, boss of the scrap metal recycling base from Foshan, said.
Old mengning can backlog some scrap copper, and sell them together when prices are higher. The recyclers around him also sniffed business opportunities. Although agents and middlemen called to order goods every day, they still covered the scrap copper in their hands.
Such “business” also sinks to the basic environmental sanitation workers. According to a big data service provider for waste products in Chengdu, at present, many environmental sanitation workers in Chengdu will consciously look for copper containing cans and electronic components, “the items were sold for a maximum of 1200 yuan a day before, and now they can sell threeorfour yuan or more.”
Although the price of scrap copper has risen greatly, the sales profit of different recycling stations is quite different. Shanghai Securities News reporter understands that compared with the previous year, the most of them have reached several times or even ten times, while the few are only 30%. According to zz91 regeneration network data, as of the 12th, the average price of main copper scrap in Jiangsu, Zhejiang and Shanghai was about 65000 yuan / ton, up 32% from the beginning of the year.
In response, Wu Xinyong, an analyst in the copper industry of Shanghai Nonferrous network, said the main factors determining the profit of scrap copper recovery are the recovery cost when recycling and the price difference before the delivery price at the time of sale. If the scrap copper is recovered at the low point of copper price before the year ago and sold at the current copper price high, the intermediate profit will be considerable.

02
“Price difference between refined waste” and the economy of waste copper are highlighted

As for the phenomenon of copper scrap is tight since this year, Wang siran, director of Ping An Futures Research Institute, told Shanghai Securities News that in practice, many products of copper processing enterprises can take refined copper as raw materials and scrap copper as raw materials. There is a price difference between scrap copper and refined copper, and the price of scrap copper is not as fast as that of refined copper.
Wei Lai, director of all color research of Tianfeng futures research, told Shanghai Securities News that since this year, downstream enterprises have been in stable demand for copper, especially in emerging fields such as new energy vehicles, electronics, home appliances and other industries, with higher demand for copper. With the continuous increase of international copper price, the economy of waste copper has been highlighted. Because of the excessive cost of using refined copper, processing and smelting enterprises tend to increase the consumption of waste copper.
“The supply of copper concentrate abroad is relatively tight this year, and there are epidemic and strike in the main production areas of copper concentrate such as Chile.” Wei Lai said.
In March, copper production in Chile has fallen for 10 consecutive months, according to data. According to the National Bureau of statistics, Chile’s copper production in the first quarter of 2021 was 1.4 million tons. The year-on-year decrease was 2.2%.
The decline in copper production has shifted some demand to scrap copper, which also promotes domestic imports of scrap copper. My non-ferrous network data show that, due to steady growth of downstream demand, the import of recycled copper has increased significantly since this year. In the first quarter of 2021, the import of recycled copper was 363700 tons, an increase of 73.39% year-on-year.
“The use of scrap copper is no longer new. The industry has mature technology to convert waste copper into refined copper. From the perspective of environmental protection and carbon neutralization, it is also in line with the trend to increase the use of waste copper. ” Wei Lai said.

Do you know the causes and hazards of aging of wires and cables?

What are the reasons for the aging of wires and cables? Can cable aging still be used? Is there any harm or harm? The following is the reason analysis and disadvantages of the aging of wire and cable arranged by Huaxing wire and cable. I hope it can help you!


Causes and hazards of aging of wires and cables
1) ACSR Cable aging reason: external force damage. According to the operation analysis in recent years, especially in haipudong, a large number of cable failures are caused by mechanical damage. For example: cable laying and installation of non-standard construction, easy to cause mechanical damage; It is very easy to damage the cables in operation by carrying out civil construction on directly buried cables. Sometimes, if the damage is not serious, it will take several months or even years to lead to the complete breakdown of the damaged part and form a fault. Sometimes, if the damage is serious, the short-circuit fault may occur, which directly affects the safety production of the power plant and the user.
2) Reason for cable aging: damp insulation. This kind of situation is also very common, generally occurs in the directly buried or row of pipe in the cable joint. For example, if the cable joint is not made up to standard or is made in humid climate, the joint will be filled with water or mixed with water vapor. For a long time, water branches will be formed under the action of electric field, which will gradually damage the insulation strength of the cable and cause failure.
Cable overhead cable
3) Cause of cable aging: chemical corrosion. When the cable is directly buried in the acid-base area, the armor, lead skin or outer protective layer of the cable will be corroded. Due to long-term chemical or electrolytic corrosion of the protective layer, the protective layer will fail, the insulation will be reduced, and the cable fault will also be caused. Unit: the cable corrosion is quite serious.
4) Cable aging reason: long term overload operation. Overload operation, due to the thermal effect of the current, the load current through the cable will inevitably lead to conductor heating, at the same time, the skin effect of charge, eddy current loss of steel armor and dielectric loss will also produce additional heat, which will increase the temperature of the cable. During long-term overload operation, too high temperature will accelerate the aging of the insulation, resulting in the breakdown of the insulation. Especially in the hot summer, the temperature rise of the cable often leads to the first breakdown of the weak part of the cable insulation, so in summer, there are many cable faults.
5) Cable aging reason: cable joint failure. The cable joint is the weakest link in the cable line, and the cable joint failure caused by the direct negligence of personnel (poor construction) often occurs. In the process of making cable joints, if there are some original nets such as loose crimping and insufficient heating, the insulation of cable head will be reduced, which will lead to accidents.


6) Causes of cable aging: environment and temperature. The external environment and heat source of the cable will also cause the cable temperature too high, insulation breakdown, even explosion and fire.
The main reasons for cable aging are listed as follows:
1. Long term overload operation. Overload operation, due to the thermal effect of the current, the load current through the cable will inevitably lead to conductor heating, at the same time, the skin effect of charge, eddy current loss of steel armor and dielectric loss will also produce additional heat, which will increase the temperature of the cable.
2. Environment and temperature. The external environment and heat source of the cable will also cause the cable temperature too high, insulation breakdown, even explosion and fire.
3. External force damage. From the operation analysis in recent years, a considerable number of cable failures are caused by mechanical damage.
4. Damp insulation. It usually occurs at the cable joint directly buried or arranged in the pipe. After a long time, the water branch is formed under the action of electric field, which gradually damages the insulation strength of the cable and causes the fault.
5. Cable joint failure. The cable joint is the weakest link in the cable line, and the cable joint failure caused by the direct negligence of personnel (poor construction) often occurs.
6. Chemical corrosion. When the cable is directly buried in the acid-base area, the armor, lead skin or outer protective layer of the cable will be corroded. Due to long-term chemical or electrolytic corrosion of the protective layer, the protective layer will fail, the insulation will be reduced, and the cable fault will also be caused. Recommended product: overhead cable
Will aging wires increase power consumption


Aging wires will increase power consumption. After aging wires, if the outer insulation sheath is damaged, it will not only increase wire consumption and power consumption, but also cause circuit fire. It needs to be replaced in time.
The aging of wires will be accelerated when the temperature is too high, and the outer insulation skin will be ignited when the temperature is too high. In real life, there are many people who do not know the common sense of the circuit. When connecting two wires, they just use steel wire pliers to screw two or three turns and do not tighten them, which leads to the small contact surface of two wires at the joint. According to the knowledge of physics, the smaller the cross-sectional area of the conductor, the greater the resistance, and the calorific value Q = I square RT. the larger the resistance, the greater the calorific value.

Several points for attention in extrusion of silicone rubber cable

Abstract

This paper presents the application of silicone rubber in the acsr cable industry, some problems and solutions in the production of silicone rubber cable.
Key words: silicone rubber, mixing, extrusion, coke burning, foaming, technology

1、 Preface

Because of its high heat resistance and excellent cold resistance, silicone rubber has a long-term temperature range of – 90-250 ℃, and has excellent electrical insulation and aging resistance. Therefore, the development of silicone rubber in cable industry is very rapid.
In the past few decades, the silicone rubber industry has been facing the challenge of meeting the growing demand of modern extrusion products market. The wear resistance, cutting and penetrating resistance, chemical resistance, oil resistance and mechanical strength of silicone rubber have been improved. As a material with high temperature of thermal aging, silicone rubber has been widely used in manufacturers and users because of its value and reliability. Nowadays, the application of silicone rubber in the wire and cable industry is developing continuously, mainly used as insulation and sheath of ship cable, aviation wire, motor lead wire, heating wire and many special purposes (such as atomic energy industry, aerospace industry, metallurgy industry, etc.).
In recent two years, the company has received orders from customers about silicone rubber insulation and sheath cables. However, because such products are not the leading products of the company, the processing technology and production equipment are not perfect. Although we have encountered many difficulties in the production process, after the joint efforts of the family, the products are delivered to the customers on time, We have learned a lot from it.

2、 Problems encountered in the production of silicone rubber cable

1. after mixing and adding sulfur, the rubber material is easy to burn and contains a lot of impurities during extrusion, which leads to breakdown of insulation voltage.
2. loose shell and blister phenomenon occur during the extrusion process of sheath.

3、 Solutions

1. technical requirements for mixing and returning
Although the processing equipment of silicone rubber is not different from that of organic rubber, it is better not to use the same open mill to process organic rubber and silicone rubber. It is better to have a special operation room for silica gel and keep the environment clean, because the mechanical and electrical properties of the polluted silicone rubber should be reduced. If special processing equipment and processing site cannot be configured for silicone rubber, it is necessary to pay attention to completely isolate the polluting materials from the coordination aids of silicone rubber and silicone rubber, because most of the impurities are from the mixing of rubber.
Because of the characteristics of silicone rubber, the plastic properties of the rubber material which need to be recycled will change after the re refining, and it is easy to pack it on the roller with fast speed. Cooling water should be put into the roller of the mixer to avoid burning of the rubber. Special attention should be paid to the use of the rubber containing bis 2.4-dichlorobenzoyl peroxide as the curing system. Because the decomposition temperature of bis 2.4-dichlorobenzoyl is about 45 ℃, the decomposition products 2.4-dichlorobenzoic acid and 2.4-dichlorobenzene are not volatile, and the rubber materials are easy to burn. In order to obtain high quality products, the following basic steps must be followed when mixing silicone rubber:
(1) . carefully weigh each kind of coordination components (such as flame retardant, vulcanizing agent, color masterbatch, etc.).
(2) . after putting the pure rubber or reinforcing rubber on the open mixer, adjust the roll distance to make the silicone rubber wrap on the roller with fast speed and fully return to the refining. Pure silicone rubber can be filled with only a little reflexion or no return refining. However, due to the silica in the reinforced silicone rubber, it must be fully refined. As long as the rubber is wrapped on the roller with high speed, the degree of re refining is appropriate.


(3) . if necessary, flame retardant, color master material, etc. shall be added to the adhesive. Some fillers fall into the receiving tray through the roller during mixing, and they should be collected and added to the rubber before the next filling is added. Rubber scraper is often used to scrape the filler from the receiving plate. It is better not to use brush, because some brush hairs may fall off the brush and mix them into the rubber. It is especially important to note that all fillers can not be added to the rubber at one time, but should be added in batches in 2-3 times. Every batch of filler is added, the rubber should be fully turned over. This can ensure the packing is evenly distributed and avoid the formation of hard packing clots. Reasonable roll distance can ensure the best mixing speed and quality of rubber.
(4) . finally, the vulcanizing agent is added to the rubber. Because the vulcanizing agent we currently use is 2.4-dichlorobenzoyl peroxide, when the rubber is too hot (no more than 4O ℃), no vulcanizing agent is added, otherwise, partial pre curing will occur, which will lead to the loss of the rubber or vulcanizer. Enough cooling water is put into the roller to avoid overheating of rubber. Finally, in order to make the vulcanizate disperse evenly, the whole roll of rubber material should be thin through several times.
2. correct use of filter screen and rubber filter pad
The filter screen is usually composed of 20-40 mesh filter plate and 60-100 mesh stainless steel filter with fine mesh. Some manufacturers do not like to extrude directly with the filter screen, because this can improve the extrusion speed and sometimes eliminate the possibility of heat generation and coke burning near the rubber filter plate. However, the use of the filter screen can not be ignored, because it plays a significant role in removing impurities and dispersed filler particles in the rubber. At the same time, the filter screen can also exclude the air in the rubber material during mixing and back mixing, especially for the softer rubber.
Because silicone rubber is only slightly thermoplastic and is not easy to be subjected to flow stress or shear strain in its unvulcanized state, the design of filter plate is not the key. Most filter plate designs are suitable for silicone rubber processing.
3. selection of extrusion equipment
In terms of equipment selection, we have no choice because we have no special silicon rubber cable production equipment at all. Among the three continuous vulcanization production equipments we currently use, the equipment that can be used for the production of silicone rubber is as follows: Φ 65/ Φ The 90 steam continuous vulcanization and extrusion machine and PLCV salt bath continuous vulcanization and extrusion machine.
4. process exploration and improvement
Because silicone cable is not our regular product, we always feel the stone across the river when we produce silicone cable. We used the insulation extrusion separately Φ 65/ Φ 90 steam continuous vulcanization and extrusion machine and PLCV continuous vulcanization extruder. But because Φ 65/ Φ The expansion pipe cannot be connected to the head of the 90 steam continuous rubber extruder, because the temperature of the head will rise rapidly after the expansion pipe is connected to the head under the steam heating, which leads to the vulcanization of silicone rubber in advance during extrusion. So in actual production, we do not connect expansion pipe to the head, but use steam in open mode, which will cause the steam pressure can not be applied too much, which affects the production speed and waste a lot of steam. When PLCV unit is in insulation extrusion, under the condition of controlling extrusion temperature, extrusion is not too big, only 0.2MPa pressure or no pressure is needed to meet the product requirements.
We are producing a number of single core cables with silicone rubber insulation and rubber sheath. Because the customers require that the insulation and sheath can be easily stripped, this means that the double layer co extrusion process we usually adopt in the production of single core cables can no longer be used. When the insulation extrusion is ready for the sheath extrusion, the problem arises: the silicone rubber insulation layer in the inner mold of the insulating wire core is easy to be driven up, which blocks the inner mold, and the bubble opening of the sheath after extrusion of the sheath. After repeated tests, we have adopted a layer of non-woven fabric in the insulation core to provide a storage space for the gas released by the silicone rubber insulation during secondary vulcanization. Under the condition of pipe pressure of 0.2-0.3mpa, the problem of being caught and blistering of sheath in the inner mold of insulation is solved.
In September, 2006, a customer customized a silicon rubber insulated silicone rubber sheath frequency conversion cable. Because the core of the insulating wire is formed, the copper tape is wrapped as the shielding layer. In order to prevent water from entering the sheath during the extrusion of the sheath, we first adopt the method of sealing the finished product head and then pressurizing, but the problems of sheath loose shell, blistering and explosion are also appeared. It is proved that we also use the method of wrapping a layer of non-woven cloth outside the shield layer of copper tape, and pressing when the head enters the vulcanizing tube 5m, which solves the problems of sheath loose shell, blistering and explosion.
In view of the success of the last few times, we blindly believe that non-woven fabric can solve the problems in the production of silicone rubber cable, but it is not all silicone rubber cables can produce qualified products by wrapping the non-woven fabric on the insulation. When the sheath is extruded after the multi-core cable is formed, although the non-woven cloth is wrapped, it is often because the cable is not filled enough, the melt pressure is not enough during the extrusion of the sheath, and the silicone rubber cannot be squeezed into the gap of insufficient filling, but the phenomenon of luller appears after the vulcanization tube is pressurized and vulcanized. Therefore, when the sheath is extruded after the multi-core cable is formed, we do not agree to add filling and wrapping non-woven cloth when the cable is formed, because the cable core has enough clearance to store the gas released by the silicone rubber insulation during secondary vulcanization. As long as the pipe pressure is applied properly, the loose shell and blister and the dew phenomenon of the sheath can be avoided completely.

4、 Concluding remarks

In conclusion, through the analysis of the problems encountered in the production process, we can not grasp the special points, and find out the causes of the problems fundamentally through the phenomenon and adopt practical technology and technical measures to solve the problems. We believe that through our efforts, the production process of silicone rubber cable will be mature, the quality of products will be improved, and the silicone rubber cable will gradually become our leading product, and the market competitiveness of rubber sheath cable will be enhanced.

Burning test for ACSR Conductor production

There are two key links in the wire and cable manufacturing industry, namely theAluminum conductors steel-reinforced production link and the wire and cable testing link, especially the wire and cable testing link. This is the last stop for quality control and a comprehensive assessment of the performance of wires and cables.
The burning test of the cable is an extremely important one of its many tests. The national cable performance classification has special grade requirements for it, such as the number GB/T31248-2014. This standard divides the burning of the cable into 4 grades, A Class (non-flammable cable or optical cable, equivalent to metal sheathed cable or optical cable), Class B1 (flame-retardant B1 cable or optical cable, equivalent to halogen-free low-smoke flame-retardant cable or optical cable), Class B2 (flame-retardant B2 cable or Optical cable, equivalent to low-halogen, low-smoke flame-retardant cable or optical cable) and Class B3 (ordinary cable or optical cable).


Especially for fire-resistant and flame-retardant special cables, the burning test is a very important test for their professional performance. These fire-resistant and flame-retardant cables are required to have certain flame-retardant properties, and they must also have a certain flame-retardant performance. The characteristics of normal operation for a certain period of time, so the burning test is also a test of the performance of this type of cable.
In addition, there are a number of data for various combustion conditions. The values ​​need to be tested. For example, the heat release rate of the cable is the heat energy released by the combustion of the cable within a certain period of time under the specified conditions. This value is the normal combustion of the cable. Detect the data, and the value of the data will be affected by many factors, such as the combustion state, and the amount of non-metallic materials.


There is also an average heat release rate, which refers to the average heat release rate within 30 seconds. The average heat release rate during the combustion process is also a value that changes with the continuation of the combustion time. The peak heat release rate is the maximum value of the average heat release rate during the entire combustion period. The standard stipulates that the combustion time is 1200 seconds, which is the maximum value among the 40 average heat release rates. This value is related to the combustion state of Aerial Bundled Cable during combustion. If the flame is particularly large in a certain period of time within 1200 seconds, the peak heat release rate may not meet the requirements. The total amount of heat release refers to the integral value of the heat release rate within a specified time.
The various test data of the cable in the flame combustion can reflect the performance and influence of the cable in the flame, and can fully reflect whether the cable is qualified and up to the standard, and whether the fire performance of the fire-resistant cable meets the requirements, these are extremely important Therefore, the burning test is also one of the routine tests of wire and cable manufacturers.

Frequency Conversion Cable Structure Design

The energy saving effect of frequency conversion device is very obvious, the use of frequency conversion speed regulating motor in high power motor, the whole generator set can save 30% electricity. And after the use of frequency conversion speed regulation, the soft start of the motor is realized, so that the motor works smoothly, the motor bearing wear is reduced, and the service life and maintenance cycle of the motor are extended. Therefore, frequency control technology in petroleum, metallurgy, power generation, railway, mining and other industries have been widely used.

 

1. ACSR Cable design

For 1.8/3KW and below frequency conversion motor special cable, and symmetrical 3+1 core and 4 core cable can only be used for the main power supply input cable, but the best use of symmetrical structure cable. Inverter and frequency conversion motor ask cable all needs to adopt symmetrical cable structure, symmetrical cable structure with three core and 3 + 3 core 2 kinds, 3 + 3 core cable structure is a small four to three core insulation wire core in the fourth core (neutral) is decomposed into three smaller insulation wire core section, the three big three symmetrical string cable core cable, special cable for 6/10 kv frequency conversion motor, the cable structure and 6/10 kv power cable, ordinary ordinary power cable is three insulation wire core adopts copper tape screened cable, special cable is made by copper wire and frequency conversion motor copper tape screened after extruded phase splitting the sheath, and symmetric cabling, The symmetrical cable structure has better electromagnetic compatibility because of the interchangeability of the wires, which plays a certain role in suppressing electromagnetic interference, can offset the odd frequency in the high order harmonic, improve the anti-interference of the special cable for frequency conversion motor, and reduce the electromagnetic radiation in the whole system.

2.Design of shielding structure

The shielding of special cables for frequency conversion motor 1.8/3kV and below generally adopts the total shielding, and the shielding for special cables for frequency conversion motor 6/10kV is composed of phase separation shielding and the total shielding. The phase separation shielding can generally adopt copper tape shielding or copper wire and copper tape combination shielding. The total shielding structure can adopt copper wire and copper tape combined shielding, copper wire braided shielding, copper wire braided shielding, copper wire braided copper tape shielding, etc. The section of shielding layer and the section of main line core are in a certain proportion. The shielded cable with this structure can resist the interference of electromagnetic induction, bad grounding and power line conduction, reduce the inductance and prevent the induction electromotive force from being too large. The shielding layer can not only restrain the emission of electromagnetic wave, but also act as the channel of short-circuit current, which can protect the neutral wire core.6/10kV frequency conversion motor special cable, considering that the cable is often affected by radial external force in the process of use, galvanized steel belt pin mounting layer is added outside the cable shielding layer (isolation sleeve is added between the shielding layer and the steel belt pin mounting layer).The steel belt pin is mainly used as the radial mechanical protective layer of the cable, and it also plays an additional role of total shielding. In particular, the steel belt armor and the copper wire and copper belt shield are two different shielding materials, which play a complementary role in electromagnetic shielding, and the shielding effect will be better.

 

3.Overhead ACSR Cable 336.4 MCM design

1.8/3KV and below frequency conversion motor special cable electrical performance according to GB/ TL2706, 2002 standard design. In addition to meeting the GBT/ L2706.2002 standard, the cable for 6/10kV frequency conversion motor has increased the electrical performance requirements such as capacitance and inductance. According to the actual use of the special cable for frequency conversion motor and the technical conditions of GB/T 12706.2002 and ABB Company for electric power transmission cable, the electrical performance parameters of the cable are determined.

  1. Main manufacturing technology of cables

In the production process of special cable for frequency conversion motor, the extrusion process of insulating wire core and cable forming process are the most critical processes.

Insulation core extrusion process Insulation core quality will directly affect the electrical performance of the cable. In order to improve the quality of cables, we choose insulating materials with high electrical performance for production. For example, 10kV cross-linked insulating materials are used for 1.8/3kV variable frequency motor special cables, and 35kV cross-linked insulating materials are used for 6/10kV variable frequency motor special cables. Imported materials are used for conductor shielding, insulating shielding and insulating materials. In the production process, we pay special attention to the purification of raw materials, shielding and insulation material extrusion close, control insulation eccentricity and insulation diameter uniformity, which can reduce the interface effect, improve the electrical performance of the cable.

Variable frequency cable requires symmetrical structure, and uniform tension of insulating wire core must be ensured during cable construction, so that the length of wire core after cable construction should be kept as consistent as possible, otherwise it will lead to structural changes, resulting in inhomogeneity of capacitance and inductance, and affect the electrical performance of the cable.

Cable Quality Defects and Their Elimination Methods

The crosslinking degree (thermal elongation) is not acceptable

If the crosslinking degree is not up to the standard, the thermal and mechanical properties of the cable are not qualified and can not meet the requirements of the working temperature of 90℃. The reasons for the unqualified crosslinking degree are as follows: first, the formula is unqualified, and the type and proportion of the complex agent is improper, so the formula should be adjusted to solve the problem; Two is the vulcanization process is not appropriate, such as the pressure is too low, the line speed is fast, the cooling water level is high, The solution is to first find out what the reason is, it may be one or several reasons exist at the same time, and eliminate the reasons.

Disqualified structure and appearance

(1) The thinnest point of insulation layer thickness is lower than the minimum value specified in the standard, or the average thickness is lower than the nominal value. The reasons for the unqualified insulation thickness are high linear speed, small amount of extruder, improper selection of mold, etc.

The solution is to reduce the linear speed or extruder speed, adjust the size of the die.

(2) eccentricity

The reason for the eccentricity is that the mold is not adjusted or the suspension control has changed after being collected and adjusted.

The solution is to keep the drape as stable as possible during driving.

The cable outside the bamboo joint is caused by the electrical, mechanical system causes the traction speed is not stable, the second is the die core is too small, or the conductor outside diameter is not uniform.

The elimination method is to check the mechanical, electrical system, troubleshooting. Properly adjust the size of the core, control the outer diameter of suburban counties as uniform as possible, more than the process requirements of the strand can be used.

Surface scratch

(1) the ACSR conductor encounters the upper or lower wall or foreign body in the vulcanized pipe. Therefore, it is required to adjust the suspension degree, try to make the wire core move in the middle of the crosslinked pipe, and clean it up in time when foreign bodies are found.

(2) there is burnt material on the outer edge of die sleeve. The solution is to adjust the temperature of the mold sleeve when starting the car to prevent overheating. Once burnt, it should be stopped immediately, or it will not get better by itself.

impurities

Most of the impurities in insulating material and semi-insulating material are brought into the process of mixing and extruder feeding. During the operation, strict attention should be paid to the cleaning of the material to prevent external impurities from mixing. Another impurity is coke pimp, its existence affects the performance and service life of the cable, so the temperature is strictly controlled when mixing and extrusion, to prevent the occurrence of coke phenomenon.

Air bubbles

There are two possible causes of air bubbles in insulation. One is caused by extrusion. The solution is to choose the right mold. The shielding layer has bubbles, the main reason is that there is water in the material, before extrusion should be dry, two is not sufficient cooling, then there will be as follows, in the isometric circumference of the line core appears a circle of bubbles.

The elimination method is to strengthen cooling, rise the water level and lower the temperature of cooling water.

(1) Cable performance is not up to standard

Disqualification of free discharge and dielectric loss

Free discharge and dielectric loss unqualified causes are very complex, it has to do with external shielding. Whether the insulation contains bubbles and impurities, and the properties of raw materials are closely related. Elimination method is to keep raw materials clean, strictly according to the process of production.

(2) cable insulation breakdown

Cable insulation breakdown is mainly caused by the insulation material mixed with impurities and external damage. Due to the strict avoidance of external damage, impurities should be avoided as far as possible. Semi-finished products should be strictly managed to prevent tripping and bruising.

(3) cushion breakdown

The main reason for the breakdown of the cushion is that the steel has burr, roll edge and puncture the cushion. The method to eliminate the steel strip is not equal to the unqualified quality requirements. The cushion is made of plastic belt with greater hardness, and the thickness of the cushion should be ensured.

Is it better to buy ACSR Cable online or in physical stores?

I don’t know whether to buy ASTM 477 MCM ACSR Cable online or in physical stores. It mainly depends on which part of the demand you need to meet. For users with higher quality requirements, you can buy them in physical stores. After all, you can get in touch with the real thing. , Specifications, voltage, etc. to prevent errors.


Those users who are more price sensitive can order directly online; the advantage of online purchase is that the price is much cheaper than offline, because it can save the cost of site rent increase and other costs, especially the one-stop supply of ACSR Cable online. Manufacturers have special supply channels and direct sales at factory prices, which is very cost-effective.


For users who are unsure about the quality of the wire purchased online, this is actually unnecessary. We can identify the quality of the product through the sample map. Users in the same city can also directly check the production workshop; and the manufacturer has spent so much money to make the website online, it is not necessary For the sake of a single order, the previous efforts have been broken, so it is still very reliable to place an order online, provided that you must look for a more formal wire and cable website.
Yu Zheng is entangled in whether the cable is bought online or bought in a physical store. Jinhaotai suggests that you can first consult the product price online, then go to the physical store to check the quality in the same city, and then decide where to buy. After all, the advantages of online and physical stores have their own advantages.

The main functions and advantages of ACSR

在先进科学技术的现代时代,许多现代工业设施已经出现在我们的世界中并存在于我们的生活中。钢芯铝绞线也是在电力中起重要作用的主要力量。ACSR是由单层或多层铝绞线在镀锌钢芯外部绞合而成的增强钢丝。内部是钢“芯”,外部通过绞合用铝线包裹在钢芯上。; 钢芯主要用于增加强度,铝绞线主要用于传输电能。它在电力和输电线路行业中占有重要地位。对于高压传输线,由于线路的路径有限,因此无法将其安装在一条路径上。对于多行,人们想出了一种使用一条路径,一组铁塔和多根电线的方法,即一条线相当于多条线。对于500KV输电线路,我国大部分地区采用悬挂四根电线的方法。这种接线方法称为同塔并联。这就是为什么某些杆用于“ L J”和“ LGJ”的主要原因。

下面简要介绍一下ACSR的优点和应用。ACSR具有结构简单,安装,维修方便,低线成本,传输容量大,并且有利于特殊地理条件如杂交河流和沟壑铺设。它具有出色的导电性以及令人满意的机械强度和拉伸强度。高强度和可扩展的塔杆间距等功能。因此,广泛用于各种电压等级的架空输配电线路。

钢芯铝绞线的缩写:“ LGJ”是绞合的铝线和钢丝,普通铝绞线“ L J”主要用于架空输电线路。ACSR的内部为钢“芯”,外部通过绞合用铝线包裹在钢芯上。钢芯主要增加强度,而铝绞线主要传输电能。它们都是裸线,用途基本相同,型号规格不同。
普通铝绞线:型号以“ L J”表示,为裸线。目前,中国一般使用铝包钢绞线(LGJ)作为导体。钢芯主要用于增加强度,铝绞线主要用于传输电能。根据电压的不同,导线的截面积也不同。例如,500 kV传输线的电流导体通常使用LGJ-400 / 35导体。其中,L是铝线的缩写,G是钢芯的缩写,J是绞线的缩写,400是铝的400平方毫米,而35是钢的35平方毫米。