The Bare conductor has no sheath, is it safe?

In daily life, many people will see high-voltage power cables in the suburbs. They are often erected in mid-air, but many people may not observe carefully. Many of the high-voltage wires that are erected in the air are bare wires. The so-called bare wires are not insulated. The cable of the skin.


Usually the wires and cables we buy have a layer of insulation. The function of the insulation is to protect the inside of the cable from damage, and to prevent us from getting an electric shock. However, the high-voltage line has no insulation, and the second is a bare wire. Why? What?
The voltage of domestic high-voltage transmission lines is often above 10,000 volts, while China’s unique ultra-high voltage technology has a higher voltage, and the cables used in high-voltage lines are basically bare wires. Generally, lines above 10 kV will be used. .


The reason whyBare conductors are used in high-voltage lines is very simple. If the high-voltage lines are to be insulated for cables, the thickness of the ordinary insulation layer is far from enough. If the insulation layer is to be used, its thickness needs to be increased. , This will make the weight of the cable become very large, will increase the maintenance cost of the later line. Moreover, such a thick insulating layer will also affect the heat dissipation of the cable. The final result of poor heat dissipation is to increase the consumption of electric energy. Therefore, comprehensively considered, the benefits of adding an insulating layer cannot offset the negative effects brought about, so simply don’t need an insulating layer. Attach bare wires directly.
From the design point of view, bare wires are obviously better than cables with insulation, but if you consider their safety issues, will the use of bare wires cause harm to people? In fact, you don’t need to worry. High-voltage lines sound terrible, but the high-voltage lines are difficult for ordinary people to reach. They are all in remote suburbs and are elevated in the air, so ordinary people can hardly touch them.
The operation of the staff also has strict operating specifications in the industry. There are air gaps between the wires and the ground, between the wires and the wires, between the wires and the ground, and between the wires and the tower. Perform accurate calculations and leave a sufficient safety distance.
So generally speaking, it is not very dangerous, but if there are high-voltage lines in the area where you are moving, you should still keep a safe distance.

What is power cables overload?

During the operation of the wire and cable, heat will be generated due to the existence of resistance. The resistance of the wire is generally very small, and its heating power can be expressed by the formula q=I^2R. q=I^2R indicates: for a piece of Power Cable in actual use (R is basically constant), the larger the current through the wire, the greater the heating power; if the amount of current is constant, the heating power of the wire is also constant . The heat released during operation will be absorbed by the wire itself and cause the temperature of the wire to rise. Although the wire is constantly absorbing the heat released by current work, its temperature will not rise indefinitely. Because the wire is absorbing heat, it is also constantly releasing heat to the outside world. The facts show that the temperature of the wire gradually rises after the wire is energized, and finally the temperature is constant at a certain point. At this constant point, the wire has the same heat absorption and heat dissipation power, and the wire is in a thermal equilibrium state. The ability of the wire to withstand higher temperature operation is limited, and operation exceeding a certain maximum temperature will be dangerous. This maximum temperature naturally corresponds to a certain maximum current, and running a wire that exceeds this maximum current is an overload. The overload of the wire directly causes the temperature of the wire itself and nearby objects to rise. The increase in temperature is the most direct cause of this type of fire.

Overload damages the insulation layer between the twin Overhead Cable and causes a short circuit, which burns down the equipment and causes a fire. The double-stranded wires are separated by the insulating layer between them, and overload causes the insulating layer to be softened and destroyed, which leads to direct contact between the two wires to cause a short circuit and burn the equipment. At the same time, the high temperature generated by the large current at the moment of short-circuit causes the line to catch fire and fuse, and the resulting molten beads fall to combustibles and cause fire. Overload temperature rise can also directly ignite nearby combustibles. The heat transfer of the overload wire increases the temperature of nearby combustibles. For nearby combustibles with low ignition point, it is possible to ignite them and cause a fire. This danger is particularly prominent in warehouses that store flammable materials and buildings that are easy to use and combustible decorations.

The output of high-performance fireproof cables reaches 40,000 kilometers

ThePower Cable industry is an industrial basic industry, and its products are widely used in energy, transportation, communications, automobiles, petrochemicals and other fields, occupying an extremely important position in my country’s national economy, and the market demand is huge.
Since the 21st century, China’s economy has continued to grow at a high speed. In particular, large-scale projects such as power grid transformation and UHV have been successively invested in upgrading and construction, providing a huge market space for the development of the wire and cable industry. Among them, the market demand for special cables such as high-temperature superconducting cables, aerospace cables, and high-performance fire-resistant cables is increasing.
Despite the huge market space in the entire industry, high-performance special cables with increasing demand have always been the shortcomings of my country’s wire and cable industry, occupying a relatively low proportion in the entire industry, showing that foreign-funded enterprises are leading the way and domestic enterprises are closely following the situation. In terms of market segments, the high-end market for special cables has the characteristics of high technical content, high entry barriers, strict protection of intellectual property rights, and high added value of products. Therefore, how to upgrade the technical level of domestic cable manufacturers, pry open the high-end market, continuous research and development, strengthen innovation, and build brands is the key.


At present, economic construction is shifting from traditional infrastructure such as “Tie Gongji” to “new infrastructure”, which brings new opportunities and new challenges to the wire and cable industry. The cable industry has entered a reshuffle period, and the industry concentration will further increase; “One Belt One Road” The implementation of the strategy has led to a significant increase in the role of overseas markets in the market structure; industry consensus and restrictions on safety, environmental protection, and energy conservation force cable companies to accelerate their entry into the high-end specialOverhead Cable market.


During the “14th Five-Year Plan”, China’s wire and cable industry will usher in new developments, and the market for high-performance special cables will exceed 100,000 kilometers. Wire and cable companies must firmly seize major development strategic opportunities such as power investment, rail transit construction, high-voltage and ultra-high-voltage transmission and distribution network construction, aerospace industry, and deep-sea mining, relying on technological innovation and focusing on digital and intelligent manufacturing. , Focusing on the fields of ultra-high voltage and ultra-high voltage power cables, high-performance fireproof cables, high-temperature superconducting cables, aerospace cables, special cables for urban rail, special cables for nuclear power, etc., strengthen the research and development of key materials and equipment, and strengthen process research , Accelerate the research and development of various new products, strive to make new breakthroughs in basic technologies and common technologies, strengthen the foundation of industrial technology upgrading, seize the commanding heights of international industrial competition, and seek the initiative for future development to promote the optimization and upgrading of the entire industrial chain of the industry, and accelerate Build an industrial basic capability system for the cable industry in the new era, create a modern industrial chain with stronger innovation, higher added value, safer and more reliable, and better support the construction of a modern industrial system.

Recommendations for BTLY cable cross-section selection

1. Select the cross section according to the temperature rise of the core
When the load current is passed, the core temperature does not exceed the long-term working temperature allowed by the cable insulation. That is to say, select according to the allowable current-carrying capacity.
Suggestion: The cable passes through different heat dissipation conditions. The corresponding core operating temperature will be different, and the section should be selected according to the area with severe heat dissipation conditions (usually no more than 1 meter).


2. Select the cross section according to the allowable range of voltage loss
When the terminal voltage of the electrical equipment actually deviates from the rated value, its performance will be affected, and the extent of the impact will be determined by the magnitude and duration of the voltage deviation.
Suggestion: The voltage loss increases due to the sharp rise of the core temperature during fire. The voltage loss should be calculated according to the fire conditions to ensure the continuous operation of important equipment. Due to the excellent heat insulation and heat dissipation characteristics of BTLY products, it is only necessary to enlarge the cable selected according to the normal situation by one to two. Usually, it can meet the condition that the voltage deviation under fire conditions is not more than -10%.
Three, select the cross section according to the economic current
The total cost during the economic life is small. That is, the initial investment and the cost of line loss during the economic life are small.
The so-called economic current is the working cable (range) corresponding to the applicable cross-section (range) during the life of the cable, the sum of investment and conductor loss costs. For details, please refer to “Low Voltage Cable Economic Current Density Range Table”.


Suggestion: BTLY products should have good heat dissipation characteristics. If the cross section is selected according to the temperature rise of the core, the selection can be reduced by one level. But taking into account the economic current factor. Therefore, it is not recommended. If selected in accordance with the routine, the line loss will be reduced by 4-7%, which is of great economic significance.
Fourth, the selection of the cross section of the neutral power cable and the ground wire
(1) In a single-phase two-wire circuit, regardless of the size of the phase wire cross section, the neutral wire and ground wire should be the same cross section as the phase wire.
(2) In the three-phase five-wire power distribution system, the allowable current carrying capacity of the neutral wire and ground wire should not be less than the sum of the large unbalanced load current and harmonic current in the line. When the phase wire core is not larger than 16mm2, the neutral wire and ground wire should have the same cross-section as the phase wire. When the phase wire core is larger than 16mm2, if the neutral wire current is small, the cross section of the phase wire can be selected, but it should not be less than 50% of the phase wire cross section and not less than 16mm2.
Suggestion: Use the aluminum metal sheath in the BTLY cable as the grounding core. The aluminum pipe grounding wire is connected by a dedicated connector, and the connection is firm and reliable. The equivalent resistance of the aluminum tube section of the BTLY cable meets the grounding needs of the corresponding copper core

Fire-retardant design of power cables in subway construction

With the acceleration of modernization, my country’s wire and cable industry is also rising. However, in the current vigorous development of the industry, my country’s per capita consumption of wires and cables is low, and counterfeit and inferior products on the market are prevalent. All have restricted the healthy development of the wire and cable industry. Therefore, we must pay close attention to the key aspects of quality inspection. Improving the quality of wires and cables is a problem that the industry should pay attention to.
Current status of wire and cable quality
In the production process of the wire and cable industry, the use of raw materials is more important than the processing technology. The cost of raw materials determines the cost of the product. In recent years, the development of the power cable industry has caused the price of raw materials to continue to rise. Large enterprises control costs by optimizing structures and improving production processes. Small and medium-sized enterprises can only survive by “cutting corners”. Some companies turn a blind eye to the latest product technical standards, and use ordinary raw materials to replace the required fire-resistant and flame-retardant materials; or use some hands and feet on the wire and cable cross-sections. This way, although the cost is controlled, the quality of the product is also greatly reduced.
After long-term development, most enterprises have been on the right track, and the production technology has become more advanced and the quality of products has gradually improved. However, quality problems still occur from time to time. The reason is that on the one hand, the enterprise squanders product technical standards in order to seek benefits; on the other hand, it is also because of the negligence of quality inspectors. Therefore, the quality inspection work of ASTM 477 MCM ACSR Cable products also requires multiple efforts to jointly recommend the healthy development of the industry.


The body is more harmful. Therefore, the application of flame-retardant cable materials can prevent corrosive gases from appearing in the cable during combustion, and only produce a small amount of dense smoke, which also reduces the damage to the equipment and the human body, which is beneficial to the follow-up rescue work after the fire. The cost of insulating layer and protective material of low-smoke flame-retardant cable is based on polyvinyl chloride resin, and then plasticizers and absorbents, high-efficiency flame retardants and marital inhibitors are added to it, and then passed It is produced by a special process. This material can greatly reduce the release of dense smoke and toxic gases produced by the burning of the material, thereby ensuring the safety of the victims and equipment under the subway. So as to reduce economic losses.

The basic structure of the wire

1. Single round wire The main varieties are copper single wire, aluminum single wire and copper-aluminum alloy wire. The diameter of the wire is used as the structural parameter, ranging from 0.01mm to 3.00mm. Except for some of the round single wires used directly as products, most of them are semi-finished products used by twisting single wires into multiple twisted wires.
In addition to the round single wire of a single material, there are also compound round single wires. Commonly used are bimetal round single wires, such as aluminum clad steel wire (high conductivity of aluminum, strong tensile strength of steel wire), copper clad aluminum wire (high conductivity of copper, light aluminum) and coated single wire, such as tinned copper wire, Nickel-plated copper wire.
2. The round stranded wire and cable are products of large length, which have to withstand many times of winding and unwinding during production, installation and use. If the wires with larger cross-sections are not used to twist small-diameter single wires into a certain cross-section Twisted wire, the product cannot be manufactured and used. Different use conditions and conditions require wires and cables to have different flexibility-that is, bendable or twistable. Therefore, the stranded wires used in various products have different requirements in terms of flexibility, etc. Therefore, 7 kinds of wire structures are specified in the wire standard. Table 1 is the wire structure specified by the standard.


Wires with the same material and the same cross-section can be composed of several structures, that is, the number and diameter of single wires are different. The more single wires in the same cross-section (the thinner the single wire diameter), the higher the flexibility of the wire.
The structural parameters of  round stranded wire are the cross-sectional area of ​​the wire (in mm2), the number of single wires and the diameter (mm), the stranded pitch diameter ratio, etc.
3. Derivative structure of round stranded wire
(1) Compact round stranded wire In the wire stranding process, the stranded wire is pressed tightly by means of a pressing wheel, etc., so that the conductor occupancy rate in the cross-section reaches about 90%. One is to flatten the protruding shape of the wire surface, which is beneficial to squeeze the thin (0.5-1mm), inner semiconductor layer (for uniform electric field) of the medium and high voltage XLPE cable, which is not easy to puncture. The second is to reduce the gap between the single lines.


(2) The diameter of the inner groove of the round stranded wire with inner hollow groove is generally 14-18mm. There are two kinds of product requirements, namely, oil-filled cables are used as oil grooves for oil flow, and high-current cables are used as channels for internal cooling through gas or liquid. (Can increase the energizing capacity). The conductor of the oil-filled cable is generally formed by twisting a Z-line or arc-shaped single wire to form a ring-shaped cross-section, and it can also be formed by twisting a round single wire into a spiral tube. As the internal cooling type forced cooling, the internal hole groove adopts a sealed metal tube.
(3) The sector conductor is the conductor structure used in the medium and low voltage 3-4 core oil-paper insulated power cable (1-10kv). It is used to make the insulated cores of the paper wrap insulation into three 120 shapes, which are twisted into a circle when the cable is formed. Shape (four-core cable is three 100, and the neutral wire 60 is sector-shaped), in order to save a lot of outer material. The line is rarely used.

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.

International Advanced Level of Environmental Protection Wire and Cable Indicators

Environmental protection wire refers to the material is environmental protection wire.

The material includes insulating material, conductor material and shielding material. Insulation such as PVC, irradiated cross-linked PVC (XL-PVC), irradiated cross-linked polyethylene (XL-PE), low smoke free (Halogen-free), silicone rubber, Teflon Telflon and so on. The environmental protection of insulation materials is mainly the EU’s RoHS environmental protection directive and the EU’s environmental regulations on children’s toys do not contain 6P (Non-6P), that is, does not contain phthalates. Now the most environmentally friendly is low smoke halogen-free, does not contain halogen elements.

The most common conductor material is copper. Copper has bare copper (brass, red copper), tinned copper, silver-plated copper wire, etc., which are essentially copper, but the surface is plated with other substances. Now there are copper – coated aluminum and copper – coated steel conductors on the market. If the electrical performance requirements are high, copper is the best. The environmental protection of conductors is mainly required to be free of heavy metals (RoHS).

Environmental protection cable means that it does not contain lead, cadmium, hexavalent chromium, mercury and other heavy metals, and does not contain brominated flame retardants. The environmental protection performance of the cable is tested by SGS recognized testing institutions, and it is in line with the European Union Environmental Protection Directive (ROSH) and higher than its index requirements. No harmful halogen gas, no corrosive gas, less fever when burning, no pollution of soil wires and cables.

Main technical indicators:

  1. Rated voltage: 450/750V and below
  2. The maximum permissible operating temperature of the conductor shall not exceed 70 ℃, 90 ℃ and 125℃ respectively.
  3. Cable combustion smoke density in line with GB/T 17651-1998 (equivalent to IEC1043) standard requirements, light transmittance ≥60%.
  4. Cable halogen acid content test conforms to GB/T 17650-1998 (equivalent to IEC 754-2) standard requirements.

(1) PH ≥4.3

(2) Conductivity ≤10μs/mm

  1. The flame retardant performance of the cable conforms to the requirements of GB/T 12666-1990.

6.Toxicity index of cable ≤3.

The Advantages of Copper Cable and Aluminum Cable

We all know that copper and aluminum are the main materials of wire and cable, so who knows what advantages copper cable and aluminum cable have?

1.Low resistivity: the resistivity of copper-core cable is 1.68 times lower than that of aluminum-core cable, with less energy consumption.

2.Good ductility: the extension rate of copper for electrical use is more than 30%, while that of aluminum alloy is only 18%.

3.High Strength: The promising strength of copper is much higher than that of aluminum.At room temperature, the promising force of copper is 7~28% higher than that of aluminum.And the stress at high temperature, the difference between the two is greater.

4.Fatigue resistance: copper repeated bending is not easy to break, aluminum repeated bending is easy to break.In terms of elasticity index, copper is also about 1.7~1.8 times higher than aluminum.

5.Good stability, corrosion resistance: aluminum core is easy to oxidize and be corroded, copper core is relatively stable, strong oxidation resistance.

6.Large carrying capacity: copper core resistivity is low, so the copper core cable can pass the maximum current carrying capacity is 30% higher than the aluminum core.

7.Low heating temperature: under the same current, the calorific value of the copper core cable with the same cross section is much smaller than that of the aluminum core cable, making the operation safer.

8.Low power consumption: Due to the low resistivity of copper, it is obvious that the copper cable has a lower power loss than the aluminum cable.This is conducive to improving the efficiency of power generation and protecting the environment.

9.Oxidation resistance, corrosion resistance: copper core cable connector performance is stable, no accident due to oxidation.The unstable joint of aluminum core cable often causes accidents due to the increase of contact resistance and heating caused by oxidation.As a result, the accident rate is much greater than the copper core cable.

10.Convenient construction: the copper core is flexible and the allowable bending radius is small, so it is convenient to turn and easy to pipe;Copper core fatigue resistance, repeated bending is not easy to break, so convenient wiring;The copper core has high mechanical strength and can bear large mechanical tension, which brings great convenience to the construction laying and also creates conditions for mechanized construction.