Can bus ducts replace cables?

Overhead cables play a pivotal role in power systems, information transmission systems, power communications and other systems. However, due to the appearance of bus ducts in recent years, many people think that bus ducts can replace wires and cables in the future. Is it really possible? Let’s talk about the difference between the two in detail below.
Overhead  Cable:
Overhead cables are used to transmit electric (magnetic) energy, information and wire products that realize electromagnetic energy conversion. Wires and cables in a broad sense are also referred to as cables for short. Cables in a narrow sense refer to insulated cables, which can be defined as: an aggregate composed of the following parts; one or more insulated cores, and their respective coatings. The protective layer and the outer protective layer, the cable can also have additional uninsulated conductors.


Busway:
The bus duct is a closed metal device composed of copper and aluminum bus bars, which are used to distribute high power to the various components of the dispersion system. It has become popular in developed countries abroad, as well as Hong Kong and Macau in my country. In Guangzhou, Guangdong, my country, where the power distribution room of buildings above 12 floors is out of line, more than 90% of the main trunk lines leading to the floor use bus ducts; 630KVA transformers must use bus ducts to the power distribution cabinet.
Busway has many advantages, and it is widely used in low-voltage power distribution system transmission trunk projects, and it is increasingly replacing cables. Compared with the technical performance of the cable or the pre-branch cable, the busway has the characteristics of good heat dissipation, low impedance and large current carrying capacity. Comparing the technical performance of bus ducts with a current-carrying capacity of 630A or higher with cables or pre-branched cables above 630A, under the same current-carrying capacity, copper can be saved by 10-35% and power loss can be reduced by more than 15%.
For this reason, bus ducts have been widely used in power transmission trunk projects of low-voltage power distribution systems, and have increasingly replaced wires and cables. But in other fields, the advantages of ABC cables are obviously more obvious, so it is impossible for bus ducts to completely replace wires and cables.

Aluminum alloy cable, copper cable, aluminum cable, who is the main ups and downs

High-quality aluminum alloy conductor sales rods are the decisive factor for the electrical and mechanical properties of aluminum alloy cables. Without high-quality aluminum alloy rods, no matter how the drawing, stranding, cabling, armoring, etc. are in the subsequent processes, they cannot be changed. The basic quality of its conductor. Aluminum alloy cable manufacturers must have an alloy formula that meets the production of AA8000 series conductor aluminum alloys, and have conductor aluminum alloy rod smelting, continuous casting and rolling production lines. That is to say, they can produce conductor aluminum alloy materials. If an enterprise does not have this basic ability, where do the rods come from? The quality of the rod material is fundamentally uncontrollable. How can we produce qualified aluminum alloy cable products? The products of this kind of enterprise are really worrying.


In terms of use, there is a big difference between aluminum alloy cables AWG and copper cables. Everyone is very familiar with copper cables. They are made of a single metal material. After decades of application, the application technology of copper cables and the supporting accessories such as connecting terminals have become very mature. Because the conductor of the aluminum alloy cable is made of aluminum alloy material, there is currently no accessory products such as aluminum alloy copper connection terminals that are consistent with the performance of the alloy cable. Currently, the industry uses copper-aluminum transition terminals that were originally used to connect aluminum cables and the recent so-called high-conductivity microalloy copper transition terminals that only improve the conductivity of the terminals (the aluminum alloy terminals are also claimed to be external, but the concept is actually confused). In fact, these application schemes are extremely wrong. Aluminum alloy cable is a new type of conductor material invented to improve the physical, mechanical, compressive creep resistance and other properties of pure aluminum cables, and there are hidden safety hazards in use. Now the application of aluminum alloy cables uses aluminum in the connection. Or the so-called non-conducting aluminum alloy that is inconsistent with the performance of the aluminum alloy cable is used as the connection, then all the defects of aluminum or non-conducting aluminum alloy still exist, and the hidden safety hazard still exists. As we all know, the potential safety hazards of cables in applications basically lie in the connection. At present, because of the existence of aluminum or the so-called non-conducting aluminum alloy in the connection of aluminum alloy cables, the advantages and value of aluminum alloy cables cannot be used and reflected at all. What is the difference between this and the direct use of aluminum cables? The truly correct and perfect connection scheme is to use aluminum alloy copper connection terminals that are consistent with the performance of the aluminum alloy cable as the connection accessory.

After comparing aluminum alloy cables and copper cables, let’s look at aluminum alloy cables and aluminum cables. There is a saying in the market that aluminum alloy cables are better than aluminum cables, even if the quality is a little bit worse, it does not matter, in fact, it is far from the case. Aluminum alloy cables that do not meet the requirements of the national industry standard for aluminum alloy cables “Rated Voltage 0.6-1kV Aluminum Alloy Conductor Cross-linked Polyethylene Insulated Power Cable” are unqualified products and are genuine fake and inferior products. Perhaps many users do not know that unqualified aluminum alloy cables are actually inferior to aluminum cables, because the base material of conductor aluminum alloy is aluminum, and conductor aluminum alloy is based on the core technical formula and process by adding other metal elements to aluminum and then alloying and smelting. , New materials made by casting and rolling, qualified conductor aluminum alloy materials can return to the level of aluminum after electrical properties are processed, and their physical and mechanical properties are much better than aluminum. Unqualified so-called aluminum alloys cannot be restored to the level of aluminum because of their lack of core technology, mature production technology and professional production equipment. Due to alloy formula, smelting, processing technology and other reasons, the electrical properties of the produced aluminum alloy cannot be restored to the level of aluminum. , The mechanical properties cannot be effectively improved, and the overall performance is not as good as aluminum. Therefore, it is better to use aluminum cables than unqualified aluminum alloy cables. After all, aluminum cables are more economical and safer than unqualified aluminum alloy cables.
Although aluminum alloy cables have been hyped up, in fact, there are only a handful of professional manufacturers with alloy cable intellectual property technology and equipment in the country that can produce qualified alloy cables. From the perspective of cost, the cost of qualified aluminum alloy conductors is similar to that of high-quality electrolytic copper. The cost advantage of aluminum alloy cables over copper cables is mainly that cables of different lengths can be produced with the same weight of materials. For unqualified so-called alloy cables, the cost of conductor materials is basically the cost of aluminum materials. For unqualified alloy cables in the market, firstly, the conductor material is unqualified. Secondly, because the manufacturer does not have core formula technology, mature alloy cable production technology and production technology, the alloy cable products produced cannot meet the requirements of qualified alloy cables. It can be said that it is fundamental It is not a real aluminum alloy cable. Such fake and counterfeit products can only be sold at low prices.

A small solution for repairing damaged insulated and sheathed cables

1. Scope of application
When the PVC insulation layer and sheath layer of the overhead cable have local defects, they are allowed to be repaired, such as broken glue, collapsed pits, disconnections, wrinkles, bumps, ears, edges, breakdowns, joints, etc.
2. Use the same plastic strips, skins, blocks and tubes for materials and equipment raw materials. The raw materials should be smooth, clean, and free of other defects. The instruments used are fine wooden files, knives, scissors, pliers, screwdrivers, copper sheets or flat and smooth cable paper. The power of hot-air plastic welding torch, electric soldering iron and welding torch for plastic welding is above 300W.
3. The repair method of local defects
Repair methods such as breakdown points, holes, and collapse pits. Repair defects with a knife and cut into plastic blocks of the same size with a slope of 45°, place them on the repair area, fix them with pliers or a screwdriver, and then use a hot air speed welding gun to continuously weld them, and use copper sheets to compact and compact them. ,To flatten. When welding plastic, pay attention to the hot air temperature of the welding torch not to be too high to avoid scorching of the plastic in the repaired area. The repaired defect is tested by a spark machine, and it is qualified if it does not break down. Use a knife to cut the defect of the plastic layer into a slope of 45°, remove the plastic block or strip with the same shape, color and thickness, and fix it with pliers or a screwdriver. After completion, connect it with a hot-air speed welding gun, then use a copper sheet to compact, compact, flatten, and finally pass the spark machine test, and it is qualified if it does not break down. Scrape the plastic defect flat with a knife, fill in the recessed part with the same plastic strip under the action of a hot-air plastic welding gun, and then flatten, compress and compact the defect repair place with a copper sheet. After the spark machine test, no breakdown Is qualified.


4. The repair method of large joints
1) Repair of general large joints: use a knife to cut the plastic layer on both sides of the broken plastic layer into a slope of 45° along the circumference, and take it clean, the color and thickness are the same, and the length and outer diameter are the same as the broken glue. The plastic pipe is cut on one side of the pipe to form openings with an angle of 45° to each other. Put it at the glue break, tie it at equal distances with a thin copper wire, and then use the same plastic strip to be welded by a hot-air plastic welding torch. After welding, use copper sheet to compact, compact and flatten. It is qualified if it does not break down after the spark machine test.
2) Repair of large joints in the production process: During the production process, due to other reasons, the temporary stop, the sheath is disconnected, and the joint can be continuously connected. The method is to cut the plastic sheath into a circular slope with a 45° angle, retreat to the machine head, extend it into the mold core mouth for 30mm, and then run the glue. After the glue is run, the crew will cooperate with each other and drive the car. Connect the plastic layers by hand, and then reshape and repair.
3) Quality defects appear in the longer length of the cable sheath from one end, and most of the sheath of the other broken end is good, and the cable length is fixed, and the large joint repair method in the production process can also be used. Only after removing the defective end of the sheath, select a larger mold on the extruder, according to the process, first extrude the end of the sheath, and gradually increase the traction speed to the large joint so that the sheath at the interface gradually It is thinned and wrapped on the original sheath that is cut into a slope shape, and it will be reshaped and repaired after the machine is off.

Why do mice like to bitepower cable?

Rats are animals that everyone shouts and beat in our daily lives. Not only do they like to steal food, they also bite. If the electrical appliances in the house are suddenly out of use, it goes without saying that the eighth achievement is that the mouse bit PVC Insulated LV Power Cable, but why Do mice like to bite wires so much? Are you not afraid of being electrocuted?
In fact, mice don’t just bite wires, wood, cardboard boxes, and plastic products. They don’t let go; this is because mice have large incisors and can grow continuously. They grow about 3 cm in about a month, so they have to keep going. Bite things to grind their teeth. Otherwise, when the teeth grow to a certain extent, the mouse’s mouth will not close, and then starve to death. It can be said that the mouse has been gnawing and gnawing all his life and can’t stop at all.


Why are they not electrocuted?
Generally speaking, a mouse will not bite aaac wires at the same time. At this time, a current loop cannot be formed. Naturally, the mouse will not be killed by electricity. If the mouse bites a live wire, because the mouse’s hair and soles have relatively strong insulation, the current cannot There is no way to electrocute the mouse by forming an electric potential difference on the mouse.
How to prevent the wires from being bitten by mice?
In order to prevent this from happening, you can bury the wires in the wall during decoration to reduce the chance of mice contacting the wires. All kinds of wire troughs, power distribution cabinets, electrical appliances, etc. must be blocked to prevent rats from getting drilled. Go in; in addition, keep the room clean and sanitary, which can also effectively reduce the breeding of mice.

How to find broken overhead cables

The core of the cable is an important part of overhead cable. We transmit information through the core of the cable. If the core of the cable is broken, it will bring a lot of troubles and dangers. If the core of the cable is broken, how should we check? Someone may I would say to take a multimeter, but if it’s a big project, can’t I also use a multimeter?
One, the method of energizing the capacitor
Some cable factories usually use the capacitance comparison method to find the approximate location of the disconnection. Using continuous power-on method to accurately determine the disconnection point of the cable, the efficiency of this method is very low. Generally, it takes about one and a half hours to find a disconnection point. With this method, it is almost impossible to find a broken core for flame-retardant cables whose shielding, armoring, and sheathing processes have been completed. If it is not done properly, the flame-retardant cable will be scrapped. This method is basically no longer needed.


2. Combination of capacitance method and induction method
This method is used for the broken core of the cable core, which requires that LV ABC  cable core is not covered with a metal layer and there is no extruded sheath. When searching, first use the capacitor to find the approximate location of the cable disconnection, and then use the induced voltage method to accurately find the disconnection point. This method is very simple and quick, and it is also the most used method at present. The induction voltage method is to connect one end of the broken core of the cable with an AC voltage of 650V, and the other end and other cores are grounded, and then test with a sensor pen that can emit light signals. When the sensor pen slides over the broken core during the test, The signal will change, so that the cable break point can be accurately found.


3. Combination of constant current source and bridge method
This method is used for finished cables or cable cores that have been coated with a metal layer. Use is to find the method is to burn the insulation at the broken core of the flame-retardant cable with a constant current source and breakdown, and then use the bridge method fault locator to accurately locate the fault point, which is also a frequently used method.

How to prevent the control cable from overloading and catching fire

As the main carrier of power transmission, industrial control cables can be widely used in all aspects of our daily lives. However, during the operation of industrial control cables, resistance heating tends to occur. However, the temperature that the wire can withstand is limited, and if it exceeds a certain temperature, there will be greater danger. For example, when the current is overloaded, it will cause overheating. When the overheating reaches a certain level, it will cause high-temperature combustion and cause a fire. So how to effectively prevent industrial control cables from catching fire due to overload?

1. In the process of industrial control cable design, the capacity of the site should be accurately verified, and the possibility of adding capacity in the future should be fully considered, and the appropriate type of wire should be selected. For large capacity, thicker wire should be selected. Industrial control cable design and reasonable selection are the key steps to prevent overload. If the design is not properly selected, it will leave inherent hidden dangers that are difficult to rectify. Some small projects and places are not carefully designed and selected. It is very dangerous to choose and lay industrial control cables at will. New electrical appliances and electrical equipment should fully consider the capacity of the original lines. If the original line does not meet the requirements, it should be redesigned and remodeled.
2. Industrial control cables should be laid by qualified electricians in accordance with relevant specifications. The laying conditions of industrial control cables directly affect the heat dissipation of the wires. Generally speaking, the laying of industrial control cables should not pass through flammable and combustible materials and stacks, which will cause poor heat dissipation of the wires, heat accumulation, and the possibility of igniting the surrounding combustible materials, which increases the risk of fire under overload conditions. The wiring in the decoration ceiling of public places should be protected by steel pipes to separate the ceiling from the circuit. In the case of overload, short circuit, etc., the molten beads will not fall to avoid fire.
3. Strengthen power management, avoid random wiring and wiring, and use mobile sockets with caution. Random wiring, random wiring, and use of mobile sockets are actually adding electrical equipment to a certain section of the line, which increases the amount of current and may cause overload. There are obviously more mobile sockets than fixed sockets on the wall. If too many electrical equipment are used on the mobile sockets, the original wiring must be unbearable. For larger power equipment and electrical appliances, separate industrial Concentric Cables should be installed, and mobile sockets should not be used as wiring sources.
4. Speed ​​up the renewal and transformation of old lines to eliminate fire hazards. In old enterprises, old residential areas and other units, many industrial control cables have been aging and have exceeded their service life due to their long use time. Even if the current-carrying capacity of some lines is not large, the aging circuit can hardly withstand such current-carrying capacity, and it also has the danger of overload. Especially in old residential areas, industrial control cables have long been aging, but with the improvement of people’s living standards and the increase of household appliances, their electricity consumption is still increasing year by year, which is really worse. For old lines, timely supervision and coordination should be carried out, and rectification should be promoted as soon as possible to eliminate fire hazards and ensure safety.
The content introduced above is to effectively prevent industrial control cables from catching fire due to overload. In order to effectively ensure that the industrial control cable catches fire due to overload, you must have the above problems in your daily use. Once these problems are found, you need to replace new cable products and take other guarantee measures in time. , So that we can effectively prevent the fire from happening and ensure the safety of our lives

 

Smart grid boosts urban green development

In the future, smart cities will not only focus on high-efficiency and intelligent goals, but also include green, environmental protection and low-carbon development goals. The construction of smart grids will promote the green development of cities. With uneven energy distribution, a strong smart grid can greatly improve the grid’s ability to accept clean energy and optimize the allocation of energy resources on a large scale. More and more smart cities in our country are incorporating clean energy into the overall planning of smart cities. Especially abc cables played a huge role in this plan,realize the transformation of the economic development direction and the optimization and upgrading of the industrial structure. The goal is to build a modern and fully internationalized world ecological garden city, and the goal is to build a smart, green, and low-carbon livable city.


In the process of realizing the smart grid to promote urban green development, power cables play a prominent role in the construction of smart grids,the State Grid took the lead in practicing and established the National Wind and Solar Storage and Transmission Demonstration Project. The project is currently the world’s leading new energy comprehensive utilization platform integrating wind power, photovoltaic power generation, energy storage, and smart power transmission. Wind power will reach 1 million kilowatts, the total scale of photovoltaic installations will reach The scale reaches 110,000 kilowatts.


There are many participants in the construction of smart grids. With the construction of smart grids, its R&D and manufacturing levels will continue to improve, and the overall strength of the aaac industry will continue to improve. City-related industries will also develop rapidly and share market shares, creating conditions for smart grid-related industries to enter the international market. In addition, the improvement of the safe and stable operation of the power grid, the improvement of power supply reliability, and the high-quality power supply have also laid the foundation for the rapid growth of traditional industries and the rise of high-tech industries.

The important influence of aluminum alloy cables on wind power generation

The proposal of “carbon peak” and “carbon neutral” goals has accelerated the development of new wind and solar energy. In 2021, onshore wind power subsidies will be refunded, which will also intensify the demand for cost reduction of wind power, resulting in a rapid increase in the application of aluminum alloy cables. In addition, the introduction of new foreign technologies has promoted the rapid advancement of domestic wind power cost reduction programs.

The application of aluminum alloy cables in wind power has mature domestic cases, mainly in the fixed laying section of the tower. The introduction of new foreign technologies has further expanded the application of aluminum cables. The use of 8030 aluminum alloy conductors and the design of category 5 conductors make it possible to apply aluminum alloy cables in the torsion section.
By benchmarking the performance of foreign aaac conductors, the aluminum conductor adopts the same stranding process as the copper cable. Because the aluminum wire is lighter, the advantage of the aluminum cable is more obvious from the point of view of flexibility.

Reducing this cost saving is the eternal theme of the sustainable development of enterprises. The weight of the aluminum alloy conductor is reduced, and the load-bearing requirements of the sheath are simultaneously reduced, and the thickness of the sheath is also reduced in response, so the loss is smaller. Using aluminum alloy torsion cable design, the cable can be designed as a whole laying plan, which reduces the design of intermediate joints and can further reduce risks and costs.

Wind power has always been the main force in the development of new energy. How to ensure the long-term fast and efficient operation of wind turbines is the direction that wind power mainframe companies have been pursuing. Development of aluminum alloy cables has reduced the cost of wind turbine cables, reduced the risk of cable decline due to its own weight, and promoted the rational application of my country’s aluminum resources.

How does the submarine cable work?

Many people are full of curiosity about submarine cables. Submarine cables are actually a kind of long-distance optical fiber. Generally, long-distance optical cables in the world use submarine cables. So how do submarine cables be laid?
Compared with submarine cables, the laying of terrestrial cables is much simpler. You only need to dig the cable trench and bury the cables in it. Submarine cables are not that simple. To lay the submarine cables, you must first have a ship. The submarine optical cable laying ship puts the submarine cable on the ship, and then the ship slowly sinks the cable into the seabed according to the prescribed route. It sounds not difficult, but the actual operation is actually very difficult. At present, the international long-distance submarine cable laying is almost unfavorable. Developed countries such as Japan and Europe have a monopoly. However, the domestic cable industry has developed rapidly in recent years. Leading companies such as Huawei have the technology and ability to lay long-distance submarine cables.


The laying of submarine optical cables is usually done by a cable laying machine that digs the seabed. The working principle is a bit like the plow used in plowing the field. During operation, the rows of water jet holes at the bottom of the cable burial machine simultaneously spray high-pressure water jets to the seabed to flush out the seabed sediment to form an optical cable trench. At the same time, the fairlead on the upper part of the equipment can guide the optical cable to the bottom of the optical cable trench. The cable laying machine is towed forward by the submarine optical cable laying vessel, and transmits various instructions through the working optical cable through the laying vessel.
In order to avoid damage to the optical cable due to too small bending radius or excessive tension, the laying of the optical cable-laying ship must use underwater monitors and underwater remote control vehicles to continuously monitor and adjust to control the sailing speed of the laying ship and the release speed of the optical cable. Control the angle of entry of the optical cable into the water and the laying tension and avoid uneven places and reefs. Of course, after the fiber optic cable is laid, there will be landfill work. In the past, sea currents were used to allow sand to naturally cover the trenches to save time for burying cables, but it was also vulnerable to sea currents and other unstable factors (such as sharks). Therefore, it is now common to use an underwater robot equipped with a high-pressure water pump to flush a ditch and then put it in and bury the soil.

What should I pay attention to when buying Aerial Bundled Cable?

As the main carrier of power transmission,Aerial Bundled Cable  HD 626 S1 Standard is widely used in electrical equipment, lighting circuits, household appliances, etc. Its quality directly affects the quality of the project and the safety of consumers’ lives and properties. There are many types of wires in the market, and you must use the appropriate wires according to your own electricity load.
Some of the wires sold in the market are cheaper and some are more expensive, and some people tend to be cheaper first. However, cheap wires often have a lot of performance that does not meet the performance described by him, and they may bring themselves Many security risks. The production technology of the wire is not too high, and the raw materials are not too different. If it is too cheap, either it is cutting corners or the quantity is not enough. How to identify it. Let me tell you several methods that are easier to identify:

  • Take a look at the packaging. National standard wires are often made better, neat, and have a sense of quality when held in hand.
  • Open the package and take a look at the wires inside. The wire thickness (insulation thickness) of the national standard wire of 1.5-6 square meters is 0.7mm. If it is too thick, it is non-standard, and its inner core is definitely not enough. , You can pull the thread hard, the ones that are not easy to tear are generally the national standard.
  • Burn it with fire, the ones that are extinguished within 5s after leaving, and those with certain flame-retardant function are (ABC) ASTM B230 Standard .Look at the inner core, the higher the brightness of the inner core material (copper), the better the copper, and the brightness is uniform, shiny, and without layering. The national standard requires oxygen-free copper to be used in the core. Non-standard, such as black rod copper, may have potential accidents.
  • The thickness of the acsr core has certain national requirements, but it is not very strict. But you can’t go wrong a lot, it’s just a small error, which is generally invisible to the eye.
    The length, the country does not mandate that the rice must be beaten, but many manufacturers have also beaten the rice, and the rice that is beaten is not necessarily the national standard, but the general national standard generally does not. Non-standard rice harvesting is just a means.
  • The country stipulates that there must be a certain mark on the wire, and the maximum size will not exceed 500mm, and the next same mark will be printed. Generally, there are product trademarks, manufacturer names, and implementation standards.