Uses of overhead insulated cables

The overhead insulated cable series products are composed of pressed copper, aluminum (aluminum alloy) conductors, inner shielding layer, weather-resistant insulating material and outer shielding layer. They not only have the power transmission characteristics of power cables, but also have strong mechanical properties of overhead cables. Compared with bare wires, this product has the characteristics of small laying spacing, high safety and reliability, and excellent resistance to atmospheric aging.
1. Uses of overhead insulated cables
Overhead insulated cable products are a new series of products for the transmission of electric energy over overhead transmission lines, and are preferred for power grid construction and transformation of 10kV transmission lines. It is the most suitable series product for line maintenance and safety. Production of flexible copper wire core 2. Implementation standards for overhead cables
1. 1KV overhead insulated cable: GB12527-90 is equivalent to the International Electrotechnical Commission IEC60502IEC227;
2. 10KV overhead insulated cable: GB14049-93 is equivalent to the International Electrotechnical Commission IEC60502.
Third, the characteristics of overhead insulated cables
1. Rated voltage: 0.6/1KV, 10KV;
2. The long-term allowable working temperature of the cable: 70℃ for PVC insulation and 90℃ for XLPE insulation.
3. When short-circuited (the longest time is no more than 5 seconds), the maximum temperature of the cable: 160°C for PVC insulation, 150°C for high-density polyethylene insulation, and 250°C for cross-linked polyethylene insulation;
4. The ambient temperature during cable laying is not lower than -20℃


5. Allowable bending radius of cable:
(1) Cables with rated voltage below 1KV: cables with an outer diameter (D) of less than 25mm should not be less than 4D, and cables with an outer diameter (D) of 25mm and above should not be less than 6D;
(2) The rated voltage of 10KV cable should not be less than 20 (D+d). Where: D—the actual outer diameter of the cable, d—the actual outer diameter of the cable conductor. This product is suitable for the lower lead of the transformer.
4. Type, name and purpose of overhead insulated cable
JKL copper core polyethylene insulated aerial cable
JKLY Aluminum Core Polyethylene Insulated Aerial Cable
JKYJ copper core XLPE insulated aerial cable
JKTRYJ soft copper core XLPE insulated aerial cable
JKLYJ aluminum core cross-linked vinyl insulated aerial cable
JKLHYJ aluminum alloy core XLPE insulated aerial cable
JKTRY soft copper core polyethylene insulated aerial cable
JKLHY aluminum alloy core polyethylene insulated aerial cable
Overhead fixed laying of soft copper core products is used for transformer down-conductor; when laying cables, a certain distance between cables and trees should be considered, and frequent contact between cables and trees is allowed during cable operation.
JKLYJ/B soft core natural color XLPE insulated aerial cable
JKLHYJ/B Aluminum alloy core natural color XLPE insulated cable
For overhead fixed laying and cable erection, a certain distance between the cable and the tree should be considered, and frequent contact between the cable and the tree is allowed when the cable is running.
JKLYJ/Q aluminum core light cross-linked polyethylene insulated aerial cable
JKLYHJ/Q aluminum alloy core light cross-linked polyethylene insulated aerial cable
JKLY/Q aluminum core light polyethylene insulated aerial cable
JKLHY/Q aluminum alloy core light polyethylene insulated aerial cable
Overhead fixed laying; When installing cables, consider keeping a certain distance between cables and trees. When cables are running, only short-term contact between cables and trees is allowed.

There are Six Materials for the Cable

We are commonly used are super five types of lines or six types of lines, although they are all cable, but the cable material is also divided into several kinds, most of them are in line with the national conditions of production!When buying a line, don’t be a pit!Don’t be greedy for cheap!

First, four iron four aluminum wire

Four iron four aluminum is one of the worst quality cable, transmission quality is poor, it is easy to appear attenuation.Resistance is about 50 Ω 100 m, up to transmit 60 meters.

The differences are as follows:

  1. Aluminum mesh wire, the inner layer of the wire skin without luster, A pull will be broken.
  2. The easiest way to do this is to use a magnet to attract the wire. If it is attracted to the wire, it proves that there is iron in it.
  3. The four wire cores of iron and aluminum are made of different materials. Compared with all copper, materials such as copper-clad aluminum are much harder.
  4. With fire, the hardness of iron is very high, with fire, will not be soft soon.

Two, copper clad copper wire

Copper coated copper wire refers to the bronze outside and coated with a layer of oxygen free copper, so it is also called bronze wire.This kind of wire is generally ignored by everyone, not many people understand it, the conductor of the bronze wire belongs to the secondary furnace copper, which contains more impurities.Resistance is about 100 meters, around 40 Ω can transfer about 80 meters, the oxidation resistance is strong, long service life.

The resistance of bronze is much higher than that of ordinary copper-aluminum and oxygen-free copper, so the effective propagation distance of copper-bronze is much less than that of copper-aluminum.However, the physical properties of copper is still relatively stable, not easy to oxidize, so the service life is longer, because the surface is plated with a layer of oxygen-free copper, the surface does not see any difference, but with fire, the oxygen-free copper layer on the surface of the copper will soon melt away.Generally speaking, 0.4 all-copper wire can only reach 80 meters, 0.45 all-copper wire can reach 90 meters, and 0.5 all-copper wire can reach 100 meters.

Three, copper coated aluminum wire

The material of copper cladding wire is an oxygen-free copper layer on the surface of the copper core of aluminum or aluminum/steel alloy core.Because aluminum conducts electricity less well than copper, the DC resistance of copper-clad aluminum conductors is greater than that of pure copper conductors.If used as a power supply, copper-clad aluminum conductors will incur additional power consumption and a much lower voltage.100 meters would be about 28 Ω resistance, to sell cheap and transmission can be roughly 100 meters, poor oxygen resistance, long service life.The tensile strength of copper-clad aluminum is lower than that of copper conductor.Do not pull the cable body vigorously during use.Why is copper-clad aluminum mesh wire more easily oxidized?Because copper and aluminum are two metals with different electrodes, in a humid environment, copper and aluminum also have a small amount of water vapor containing impurities to form a galvanic cell.Aluminum is the negative electrode, copper is the positive electrode, the metal aluminum is corroded, so it can not be placed in the place of high air humidity.So in the choice of cable, how to see their use is copper aluminum cable?Fire can be used, if the core of the wire is quickly softened (this identification method is very practical), it proves that the copper core of the wire contains aluminum.

Four, high conductivity aluminum mesh wire

High conductivity aluminum wire, its composition is not just copper silver composition, in fact, is a kind of copper aluminum silver alloy of high performance wire, usually also known as copper coated silver.Has a resistance is small, the characteristics of the transmission is far, compared with the copper, iron and aluminum cable, resistance would be about 20 Ω 100 meters, can transmit 120 meters, but the oxygen resistance is poor, life is not long.There are three main kinds of high conductivity aluminum mesh wire: copper coated aluminum mesh wire (aluminum in the middle, the surface is thin oxygen-free copper layer), high conductivity aluminum mesh wire (imported aluminum, copper coated surface), copper coated silver mesh wire (imported aluminum, full copper coated layer)

 

Five, copper coated silver cable

The main material of copper coated silver wire is imported aluminum, which is higher in purity than copper coated aluminum wire and high conductive aluminum wire. The inner and outer leather is made of new materials.Resistance would be about 15 Ω 100 meters, which can transmit 150-180 meters, but the oxygen resistance is poor, life is not long.Copper coated silver because it can be transmitted far, we can generally be used in ADSL, computer room, supermarket, warehouse such occasions, the general network transmission is no problem.Compared with the copper coated silver wire, the transmission speed is not so long, but it is not far away. It can also be used in supermarkets, warehouses, and families in small and medium-sized areas.There is also a small amount of aluminum in the copper – silver – coated wire, and aluminum is easily oxidized.With four or five years will probably be oxidized, so in the use of choice, to consider this factor.

We can see from the copper core wire skin, generally speaking, all copper wire is the outer new material, and oxygen free copper is inside and outside the new material.You can see from the luster of the leather and cut a section of the leather to see if it can be drawn. The bright luster is the new material, and the new material can be drawn.But now all copper wire also tends to inside and outside the new material, so it can only be used as a basic basis.

You can also use a knife to scratch a surface or cross section:

Oxygen-free copper wire: scrape off the surface of a layer, the color is basically no difference, the cross section color is uniform, no difference.Bronze wire: scratch off a layer of surface, surface and interior color difference, cross section has a little white spots.You can also use fire, copper surface coated with a layer of oxygen-free copper, in the burning process, you will find oxygen-free copper outer layer will melt, and then wipe with paper, will find that the copper core is difficult to change back to the original brass color;And oxygen-free copper does not contain impurities, in the burning process, only the surface oxidation, after wiping with paper, or restore yellow.

According to the standard, the oxygen content in the oxygen-free copper wire is not more than 0.003%, the total impurity content is not more than 0.05%, and the purity of copper is more than 99.95%.Therefore, oxygen-free copper has high conductivity, good processing performance, welding performance, corrosion resistance and low temperature performance, and is suitable for high quality wire material.Oxygen-free copper cable 10 Ω resistance is about 100 meters of less than, can transfer about 120-150 meters, the signal transmission distance, packet loss rate is low, so in high-definition monitor network engineering, network engineering and home decorating go dark lines are suggested to use oxygen free copper, network stability is guaranteed, the oxidation resistance is strong, long service life.

So here’s the problem:

The above mentioned 6 materials of network cable, two of which have a relatively high transmission distance, theory can transmit about 150 meters, copper coated silver and oxygen free copper, then which one is better?Under normal use environment, the service life of the copper coated silver wire is much shorter than that of the oxygen free copper wire. The antioxidant of the copper coated silver wire is very poor, and the longest can be used for 4-5 years. The oxygen free copper wire can be used for more than 10 years due to its high purity and high antioxidant.When using copper coated silver cable, it should be noted that whether to use copper coated silver or not depends on the service life.

A final note:

Referring to various material cable transmission distance, before mentioned their resistance, cable transmission distance has much to do with the resistance, the smaller the resistance, the smaller the loss, transport the farther the distance, can be seen from the above, oxygen-free copper cable resistance minimum, and resistance to oxidation, it is also the reason why we should choose in the actual project it.

Cable Knowledge: Classification, Use and Function of Armoured Cables

ABC cable is made of conductors of different materials mounted in insulated metal bushing, which is processed into a flexible and solid assembly.Armoured cable is generally fixed power cable, generally speaking, is fixed in a place and basically do not move, power line transmission of electric energy.The armoured cable includes armoured thermocouple, armoured thermal resistor, armoured heater and armoured lead, which are mainly used for temperature measurement, signal transmission and special heating in chemical industry, metallurgy, machinery manufacturing, power generation and scientific experiments. The largest amount of armoured thermocouple is used.

Classification of Armoured Cables

Armoring is classified into steel tape armoring (22,23), fine steel wire armoring (32,33) and coarse steel wire armoring (42,43).

Steel tape armoured cable models are VV22, VVP22, ZRVV22, NH-VV2;

Control cable steel tape armoured cable, models are KVV22, KVVP2, KVVP22, ZR-KVV22

Steel wire armoured power cable, model VV32, YJV32, ZR-VV32

Steel wire armoured control cable Cable model KVV32 KVVP32

Armored communication cable models: HYA53, HYAT53, HYA23, HYV22, HYA22(rat proof, buried)

 

 Model Meaning of Armoured Cable

In order to enable the cable to withstand the radial pressure, double steel tape and gap wrapping technology is adopted, which is called steel tape armoured cable.After the cable is finished, the steel strip is wrapped around the cable core and the plastic sheath is extruded. This type of cable is expressed as control cable KVV22, plastic cable VV22, communication cable SYV22, etc.The two Arabic numerals in the subscript of the cable type, the first one: “2” means double steel tape armoured;The second: “2” represents the PVC sheath, such as the use of polyethylene sheath to change the “2” to “3”. This type of cable is generally used in the bearing pressure is relatively large occasions.For example: through the highway, square and vibration of the highway, railway side, etc., suitable for buried, tunnel and pipeline laying. In order to make the cable able to bear large axial tension, the cable is wrapped with several low carbon steel wires, which is called steel wire armored cable.After the cable is finished, the steel wire is wrapped on the core wire according to the necessary pitch and then the sheath is extruded. The representation method of this cable type is such as control cable KVV32, plastic cable VV32, coaxial cable HOL33, etc. Two Arabic numerals in the model, the first one: “3” represents fine steel wire armor;Second: “2” for PVC sheath, “3” for polyethylene sheath.This type of cable is generally used in large span, laying the occasion of large drop.

Application of Armored Cable

Armour cable mechanical protection layer can be added to any structure of the cable, to increase the mechanical strength of the cable, improve the ability of corrosion resistance, is designed for the vulnerable to mechanical damage and erosion of the area.It can be laid in any way, and it is more suitable for direct buried laying in rock areas. Armoured cable is generally fixed power cable, generally speaking, is fixed in a place and basically do not move, power line transmission of electric energy. In addition to the above purposes, the cable with armoured layer can also enhance the tensile strength, compressive strength and other mechanical protection to extend the service life. Armour has a certain resistance to external force, but also can be wary of rat bite, not through the armor caused by power transmission problems, the bending radius of the armor should be large, the armor layer can be grounded, protect the cable. Foreign armoured cable production is mainly concentrated in several more developed countries, such as the United States, Britain, Japan, Germany, Russia, Southeast Asia has no manufacturers, but as long as there are chemical, metallurgy, machinery manufacturing, power generation and other industries where there is temperature measurement, the need for armoured cable.

The Role of Armoured Cable

Armoured cable refers to the cable with metal armored protective layer. The purpose of the cable with armored layer is not only to enhance the tensile strength, compressive strength and other mechanical protection to extend the service life, but also to improve the anti-interference performance of the cable through shielding protection. The commonly used armoring materials include steel strip, steel wire, aluminum strip and aluminum tube, among which the steel strip and steel wire armoring layer has high magnetic permeability and good magnetic shielding effect, and can be used to resist low frequency interference, and can make the armored cable buried directly without penetrating the pipe, and is cheap and fine, so it is widely used in practice.

Safe Use of Cable: How to Prevent Wires and Cables from Catching Fire Due to Overload of Wres

Wire and cable in the process of operation, due to the existence of resistance will be heated.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 that: for a section of wire in use (R has been basically constant), the greater the current through the wire, the greater the heating power;If the current constant, then the wire heating power is constant.The heat released during operation will be absorbed by the wire itself, thus causing the temperature of the wire to rise.

Although the wire is constantly absorbing the heat released by the current in the process of operation, its temperature will not rise unlimitlessly.Because while the wire is absorbing heat, it’s also releasing heat into the outside world, and it turns out that the temperature of the wire increases gradually when it’s energised until it stays at a certain point.At this constant point, the heat absorption and release power of the wire are the same, and the wire is in thermal equilibrium.There is a limit to the ability of wires to withstand higher temperatures, and operating above a certain maximum temperature may be hazardous.This maximum temperature also corresponds to a certain maximum current, above which the wire is overloaded.Overloading of the wire directly causes the temperature of the wire itself and the objects nearby to rise.Rising temperatures are the most direct cause of such fires.

Overload causes the insulation layer between the two wires to be damaged, causing a short circuit, burning down the equipment and causing a fire.The double wire is separated by the insulation layer between them. Overload makes the insulation layer soften and destroy, which leads to the direct contact between the two wires, causing short circuit and burning 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 molten beads generated fall to the combustible material to cause the fire.Overload temperature rise can also directly ignite nearby combustibles.The heat transfer of overload wire raises the temperature of combustibles nearby, and it is possible for combustibles nearby with low ignition point to ignite and cause fire.In the storage of flammable goods in the warehouse and the use of easy, combustible decoration of the building, this risk is particularly prominent.

 

The overload also puts the connections in the line under conditions of overheating, which speeds up the oxidation process.Oxidation makes the connection point produce a thin layer of oxide film, which is not easy to conduct electricity. The oxide film increases the resistance between the contact points, resulting in ignition and other phenomena, causing fire.So, how to prevent the overload of wires and cables caused by fire?

In the process of line design, we should accurately check and ratify the capacity of the site, fully consider the possibility of new capacity in the future, and choose the right type of wire.Large capacity, should choose a thicker wire.Circuit design and reasonable selection are the key steps to prevent overload.If the design selection is not correct, it will leave a congenital hidden danger that is difficult to rectify.Some small projects, places not serious design and selection.Arbitrary selection and laying of lines, this is very dangerous.New electrical appliances, electrical equipment should be fully considered the bearing capacity of the original line.If the original line does not meet the requirements, it should be re-designed and transformed.

The line should be laid by qualified electricians according to the relevant specifications.The laying conditions of the circuit directly affect the heat dissipation of the conductor.Generally speaking, the line laying should not pass through easy and combustible materials and stacking, which will lead to poor heat dissipation of the wire and heat accumulation, resulting in the possibility of igniting combustible items around, and increasing the risk of fire caused by overload;The lines laid in the ceiling of the decoration of public entertainment places should be protected by steel pipes to separate the ceiling from the line. In the case of overload and short circuit, even if there are molten beads, they will not fall off to avoid fire.

Strengthen electricity management, avoid disorderly wiring, random wiring, careful use of mobile socket.Disorderly wiring, random wiring, the use of mobile socket is actually in a certain line to add electrical equipment, increase the current and may cause overload.The jack of the mobile socket is obviously more than the fixed socket on the wall. If too much electrical equipment is used on the mobile socket, the original line must be difficult to bear.Separate lines should be set for high-power equipment and electrical appliances, and mobile sockets should not be used as wiring sources.

Accelerate the renewal and transformation of old lines to eliminate fire hazards.Old enterprises, old residential areas and other units, due to the use of a long time, many lines have been aging, more than the service life.Even if the carrying capacity of some lines is not large, the aging lines are difficult to bear such carrying capacity, and also have the risk of overload.Especially in the old residential areas, the lines have long been aging, but with the improvement of people’s living standards and the increase of household appliances, the electricity consumption is still rising year by year, which is really worse.For old lines, we should timely supervise and coordinate, and promote their rectification as soon as possible, so as to eliminate fire hazards and ensure safety.

A qualified cable, these steps can not be less

A qualified cable, which can not be short of 600V Overhead Aerial cable 54.6m㎡ as a means of transmitting electrical energy and communication signals, is undoubtedly the existence of blood vessels and nerves in the modern era of the Internet, is the key to manufacturing in most industries today.

Chinese cable industry is now a large-scale, is a major international cable manufacturing country, the domestic cable manufacturing industry is only the second largest manufacturing industry after automobiles, but the huge industry has also spawned a lot of chaos and speculators, many small cable enterprises, in order to seize the market, maliciously underpricing, producing unqualified cable and wire without enough work and materials, and even worse, using fake cable and wire to list well-known cable and wire brands for sale, has had a very bad impact on the industry.

In the production of cable, in strict accordance with the production requirements and procedures, and conduct a comprehensive testing and testing to ensure that URD Cable out of the factory is of high quality, today to talk about the production of a qualified cable, what are the key steps? First of all, of course, it is strictly controlling the purchase of raw materials.

If it is a good raw material, then the quality and life performance of the cables produced will be greatly reduced. Meanwhile, Shenghua cable will strictly control the purchase, production, transportation, sales and other links, compare the raw materials from the suppliers in all aspects to ensure that the raw materials obtained are of high quality and durable; with good production materials, the next step is the production process. Huaxing cable has the latest cable production equipment.

During the production process, it also requires operators to work strictly in accordance with the requirements, whether it is extrusion machine series, drawstring machine series, stranding machine series, wrapping machine series, Huaxing cable are to achieve strict production requirements. Inspection is the most important link in the cable production process, Shenghua cable is of course also attached great importance to, for a long time, huaxing cable has always insisted on the survival of quality, to ensure safety, to service credibility, to management to promote efficiency, to forge ahead. Through the strict check and inspection of each link of the production cable, the product quality is ensured and the customer requirements are met.

Why should the length of power cable be reserved?

It is very difficult to repair and replace600V 90°C XLPE ACWU90 AC90 Cable, especially when the middle section is in trouble, because the cable is laid in the open, the bridge, the buried, the cable trench and the pipe. So in the cable laying is required to reserve. Not only in the cable trench in the feeder, but also to reserve the end; if it is tube or cable trench laying, in the middle of the maintenance wells to reserve a certain length.

Advantages: When the power cable is connected to the feeder circuit or equipment, the copper nose needs to be pressed and the outer protective layer of the cable needs to be removed And the distribution cabinet, control cabinet itself is also relatively easy to affect the cable, so the cable in both ends need to reserve a certain length to deal with the subsequent maintenance.

Otherwise, it will be difficult to deal with the problem in the figure below. The advantage of the reserved maintenance well: When the power cable is laid secretly, a maintenance well must be set up at a certain distance, which is mainly used to deal with the inspection and repair of the fault in the middle part ofPVC XLPE Insulated Power Cable 25mm² ~ 400mm². If a section is damaged by external forces or problems, the amount reserved in the manhole can be used nearby, making maintenance convenient and time-saving. Otherwise, it is very difficult to deal with the following problem.

Other benefits: due to the general cable laying path is generally more complex, often need to turn bend, calculation of cable length can not be accurate, appropriate length can also be reserved for laying a variety of special circumstances.

Cable maintenance tips

Everyone knows that everything will deteriorate after being used for a long time, and the same goes for wires. WhenAerial Bundled Cable (ABC) HD 626 S1 Standard is aging for household or commercial use, it is easy to cause danger if it continues to be used, and timely inspection can eliminate potential safety hazards. But how to detect wire aging in time requires some tricks.
The wire is mainly insulated by the outer layer of sheath. After a long time, it will be corroded by corrosive gas, and the insulation performance will gradually decrease. It will gradually age and become hard, become brittle or fall off, and then it will not be insulated. In fact, the direct cause of the aging failure of the wire and cable is the breakdown of the insulation due to the degradation.
1. “Check the appearance along the wire, darkening and hard cracks are seen. Bending the wire with both hands for insulation, stiff and cracked skin.” It means to observe the insulation layer along the wire. If the color of the insulation layer is found to be tarnished, darkened, or changed Hard, cracked, and partially peeled off.


When the insulated conductor is bent with both hands, the wire is stiff, even the insulation layer is cracked, the insulation layer falls off, etc., which shows that the wire has experienced different degrees of aging and severe aging.
2. “Accurate method to measure insulation, megohm is not low. The humidity value in rainy days can be small, and the value can be less than half.” It means that the insulation resistance meter can be used to measure the insulation of electrical circuits to determine the insulation status of the circuit more accurately.


3. If the wires cannot be replaced in time, you can also choose to use good internal materials to reduce hidden dangers. Once the insulation of the sheath of the wire casing is damaged, the possibility of fire will increase. The length of time for causing a disaster has a lot to do with the quality of the oxygen barrier. The newly produced diamond mud ceramic silica gel with silicone rubber as the base material by Shanghai Tengruina Chemical Technology Co., Ltd. has good high temperature resistance, fire resistance and fire resistance. The effective prevention and control of fire sources is to prevent fires to a certain extent. avoid lost. If there is a fire around the line, the shell of diamond mud ceramic silicon rubber can also ensure that it will not melt or drip in the flame, which effectively protects the normal use of the line and avoids explosions.
Finally, the editor still has a small reminder: the wire is aging, and the wire needs to be replaced in time. Don’t have a fluke mentality. The diamond mud oxygen barrier can only reduce the possibility of fire. Once a fire occurs, it will affect manpower, material resources and financial resources. The losses should not be underestimated!

Talk about the common misunderstandings of those wires and cables

Nowadays, there are many kinds of wires and cables, and their performances are diverse. When buying All Aluminum Alloy Cable

, many people choose to learn about the various parameters and evaluations of the cables on the network, but because the information on the network is too complicated, it is difficult to distinguish between true and false. , Some wrong viewpoints will cause misunderstandings to many people who browse and watch, so many misunderstandings about wires and cables are formed. Here is a summary of several common misunderstandings.

Misunderstanding 1: There is radiation in wires and cables

Many people have seen on the Internet that wires and cables have radiation. To be honest, there is radiation, but those who have a little knowledge of physics should know that everything that uses electricity has radiation. Even an electric fan has radiation. Except for those high-risk radiation products, the amount of radiation from ordinary wires and cables is negligible and basically negligible.

And what you may not know is that the radiation of wires and AAAC cables is even weaker than that of the mobile phones we carry around every day, so those who are afraid of radiation from wires and cables, the first thing to do is not to stay away from wires and cables, but Throw away the phone quickly.

There are also some people who worry about the magnetic field generated by wires and cables, and think that this kind of magnetic field has an unhealthy effect on the human body. If they are worried about the magnetic field, it is even more nonsense, because everyone knows that our earth has a natural geomagnetic field , And it has a larger range and stronger power. If the magnetic field is not good for the human body, the entire earth is no longer suitable for human habitation. Our Mars immigration plan can only be started in advance, so we are worried about the radiation magnetic field of wires and cables.

How to find the fault point after the ACSR cable is short-circuited?

Generally speaking, when the ACSR conductor has a short-circuit fault, the air switch cannot be closed, which will not only cause a small-scale power failure, but if it is not handled properly, it may sometimes expand the scope of the fault and even cause an electric shock accident. Therefore, if the short-circuit fault is not eliminated, illegal power transmission is absolutely not allowed.

When dealing with a short-circuit fault of a cable, try not to break the cable destructively. In that case, it will damage the cable insulation, reduce the insulation strength of the cable, and cause electric shock. So, how to find the short-circuit point quickly and effectively when the cable has a short-circuit fault?

 

 

The main methods are as follows:

1. The place where the cable has a connector is the frequent occurrence point of cable short-circuit faults. When searching, the main search object is the cable connector.

ASTM 477 MCM ACSR Cable

2. If ASTM 477 MCM ACSR Cable is erected for a long distance, and there is a short circuit in the middle or at the end of the cable, the tripping time of the air switch may be delayed. This is because the short-circuit point is far from the air switch and there are A certain resistance value reduces the short-circuit current. If this is the case, the section of cable from the short-circuit point to the circuit breaker will definitely heat up and be higher than the temperature of the human body, and the rubber sheath will become soft or even bulge. At this time, touch the hot cable with your hand until it suddenly becomes cold. The place where you feel the cable hot is the short-circuit point.

3. If it is a two-core lighting cable, the light bulb from the short-circuit point to the power circuit breaker will emit light, but due to insufficient voltage, the light will be dim, and the light bulb after the short-circuit point will not light up at all.

What effect does the cable sheath have on the PVC Sheath Flexible Cable ?

The sheath is the “skin” of the wire and cable and the appearance that people look directly at. It must be smooth and round, uniform in color, not eccentric, not damaged, free of impurities, free of bubbles, and not flattened, twisted, etc., except In addition to being unsightly, the thickness of the sheath also has a certain impact on the quality of H05VV-F H03VV-F PVC Insulated cable.

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  1. Reduce service life
    After the cable is laid, it will be energized for a long time, which will generate heat. The allowable working temperature of the conductor is 70℃. The long-term use temperature of polyvinyl chloride should not exceed 65℃. If it is summer, the working temperature will rise, and these temperatures will pass outside. When the sheath is emitted, the thickness of the sheath increases, and the heat energy is difficult to dissipate, which will affect the service life of the cable. Due to the heat of PVC, the insulation layer will undergo a series of physical and chemical changes and lose its original excellent performance. , Resulting in a significant decrease in insulation performance, and even a short circuit, affecting the normal operation of the unit.
  2. Material performance defects
    The performance of the material is not reflected by the thickness. According to the requirements of the GB8815-2002 standard, if one of its indicators does not meet the standard, the flame-retardant PVC material, its oxygen index is lower than 30.
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  1. There are problems with the cable structure
    Conductor, insulation layer, and braid density are strictly controlled in accordance with the requirements of the standard. If the outer diameter of the cable is normal but the sheath is too thick, it is very likely that other structures are cutting corners.
  2. Increase the difficulty of cable laying
    At present, cable laying is mainly based on bridges or pipes. Many companies are implementing tight cable requirements and small outer diameters. There can be gaps during the laying process to dissipate heat and ensure that the outer sheath of PVC cable is not damaged. Otherwise, the construction unit and Cable laying brings difficulties.
    To sum up, the thickness of the sheath should be strictly controlled in accordance with the standard, which not only saves resources, reduces material consumption, and increases profits for the enterprise, but also ensures the quality of the cable and creates high-quality and low-cost products.