Misunderstandings in the process of wire installation meeting (2)

Power cables bring light to the home, add all kinds of fun to life and meet the needs of family life. However, if negligence in the process of wire installation, it is easy to cause various hidden dangers in the home environment.

Misunderstanding 3: The wires are buried directly without casing
Some irresponsible construction workers buried the wires directly on the wall during the construction process, the wires were not covered by the insulating tube, and the wire connectors were directly exposed. This may cause hidden dangers and is a typical cut corner. In the future life, the wires lack protection, are easy to be bitten by rats or suffer external damage, and the wires are short-circuited, the wiring specifications of the wires are clear, they need to be protected with insulating sleeves, and the connectors cannot be exposed. Therefore, during the construction supervision period, the owner needs to supervise Whether the construction party performs construction as required.


Misunderstanding 4: Install socket cables at will
The power cord needs to use a copper wire cross-section. If you live in an old house, you need to replace the original aluminum wire with copper wire. Because the aluminum wire is easily oxidized, the connector is easy to catch fire. An investigation shows that the incidence of electrical fires in residential buildings usingAerial Bundled Cable (ABC) ASTM B231 Standard is dozens of times that of copper wires. In addition, for aesthetics, many households will use slotted buried wires and buried pipe laying methods, and wiring needs to be followed. “The live wire is inserted into the switch, and the neutral wire enters the lamp holder” and the principle that there is a leakage protection device on the socket.

Home circuit safety

Overload is also called “overload”. For example, the load capacity of a certain type of car is 4 tons, and the load exceeding the stipulation is “overload”, which is easy to damage the car, and the electric wire also has its load regulation. The current passing through the wire will heat the wire, which is normal. However, if it is overloaded and the thin wire passes a large current, it is easy to cause a fire.Install the bare wires indoors, the ambient temperature should not be higher than 35c, choose the wire in the safe current of the wire, the wire will not overheat. However, when the power consumption exceeds the current carrying capacity of the wire, the wire will generate heat. The heat of the wire is proportional to the square of the current intensity. If the current intensity is increased by 2 times, the heat generation will increase by 4 times compared to the original, which will cause the wire to overheat and easily cause a fire.

Misunderstandings in the process of power cable installation meeting (1)

Power cables bring light to the home, add all kinds of fun to life and meet the needs of family life. However, if negligence in the process of wire installation, it is easy to cause various hidden dangers in the home environment.
Misunderstanding 1: Strong and weak electricity sharing
AC power is usually used in our homes. In order to facilitate the construction, some construction teams directly store the wires together. Power cords, network cables, telephone lines, etc. are all placed in the same base, which will cause interference between the wires and unstable signals. It will also bury the hidden dangers of home fires. Strong current and weak current should be wired separately. Strong current and weak current sharing tube and bottom box are strictly prohibited. The parallel spacing of the strong current should be no less than 3cm, no less than 50cm, and the intersections should be at right angles.


Misunderstanding 2: Duplicate wiring
In order to make the pipes look clearer, some construction workers use a pipe for each wire, so many pipes are buried in the wall. It is difficult to find the location of the problematic pipe or most of the wall needs to be damaged when repairing in the future. And the structure of the ground can find the problem. Generally speaking, the pipeline should be made into a “live line”, in the case of less than 40% of the pipeline capacity, put Aerial Bundled Cable (ABC) HD 626 S1 Standard in the same direction in the pipe, which is economical and avoids the trouble of future maintenance.

 

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!

Why is the cable hot?

In recent years, various types of electrical appliances often catch fire in our daily lives. Therefore, when using electrical appliances, the cables need to be protected. However, I don’t know if you find that the cable will heat up during operation. Is it a manifestation ofAerial Bundled Cable (ABC) HD 626 S1 Standardquality problems? Or is it a normal phenomenon of cable use? What is the cause of the cable heating during operation? How should we deal with the heating of cables?
If the cable becomes hot during operation, this does not mean that there is a problem with the cable quality, but the normal operation of the cable. As long as the cable passes a certain load current, it will definitely heat up, and as the load current increases, the surface temperature of the cable will be higher. Therefore, it is basically normal to control the surface temperature of the wire below 60 degrees.


The reasons for the cable heating during operation are as follows:
1. The cable conductor resistance does not meet the requirements, causing the cable to generate heat during operation.
2. Inappropriate cable selection, for example: the conductor cross section of the cable is too small, and overload occurs during operation. The heat dissipation and heat dissipation of the cable are unbalanced after long-term use, causing the cable to heat up.
3. When the cables are installed too densely, the ventilation and heat dissipation effect is not good. OrAerial Bundled Cable (ABC) SANS 1418 Standard is too close to other heat sources, which will affect the normal heat dissipation of the cable, and may also cause the cable to heat up.
4. The manufacturing process of the cable joint is not good and the crimping is not tight. If the contact resistance at the joint is too large, it will also cause the cable to heat up.


5. The insulation performance between the phases of the cable is not good, which leads to low insulation resistance and heat generation during operation.
6. Part of the sheath of the armored cable is damaged. After the water enters, it will slowly damage the insulation performance. As a result, the insulation resistance will gradually decrease, and it will also cause heat during the operation of the cable.
After the cable heats up, if the cause is not found, the fault should be eliminated in time, and the continuous power operation will continue. The insulation thermal breakdown phenomenon will occur, causing the cable to short circuit and trip between the phases, which may cause a serious fire.
So, how to deal with the heating of the cable? Since the cable heats up when there is current passing through it, we cannot cool the cable in cold water because this will cause water to enter the cable and affect the use of the cable. Therefore, when using the cable, we can only pay attention to the use time of the cable and distribute the power reasonably. The cables should be checked regularly to see if they are old or damaged. If this is the case, the cable should be replaced in time to avoid causing the cable to catch fire.

Low-voltage cable head production and installation

(1 )Overview

Low-voltage cables have many specifications and models. Take indoor PVC insulated PVC sheath below 1KV as an example to illustrate the production of power cable terminal cable heads.

(2) Construction process

Measure the grounding resistance → strip the cable end → wrap the cable and sheath the terminal end of the aerial bundled cable ASTM b231 → press the cable core wire lug → connect with the equipment

(3) Main construction methods and technical measures

1) Press cable core wire lug

a. Measure the length from the end of the core wire to the depth of the wire nose, add another 5mm, strip the cable core wire insulation, and coat the core wire with petroleum jelly.

b. Insert the wire core into the wiring nose, and use crimping pliers to press the wiring nose. There should be more than two crimping holes. Large-size wiring terminals should be crimped by hydraulic machinery.

c. According to different phases, use yellow, green, red, and four-color plastic tapes to respectively wrap each core wire of the cable to the crimping part of the terminal lug.

d. Fix the cable with the terminal head on the pre-made cable head bracket, and separate the core wires.

e. According to the model of the terminal, use bolts to crimp the cable terminal on the equipment. Pay attention to the bolts from top to bottom or from the inside to the outside. Flat washers and springs should be installed.

2) Telemetry cable insulation

a. Use 1KV shaker to measure the cable, and the insulation resistance should be greater than 10MΩ.

b. After the cable shake test is completed, the core wires should be discharged to the ground respectively.

3) Wrap the cable, cover the cable terminal head cover

a. Strip the outer insulation layer of the aerial bundled cable(abc) b230 standard, and put the lower part of the cable head cover into the cable first.

According to the type and size of the cable head, according to the length and inner diameter of the cable head sleeve, wrap the cable with a plastic tape in a half-stack method. The plastic tape should be tightly wrapped, and the shape should be like a date.

c. Put the upper part of the cable head cover on, butt and cover it tightly with the lower part.

The principle of omission in the model: copper is the main conductor material used in wire and cable products, so the copper core code T is omitted, except for bare wires and bare conductor products. Bare wires and bare conductor products, power cables, and magnet wire products do not indicate major category codes, and electrical equipment wires and cables and communication cables are also not listed, but subcategory or series codes are listed.

Item 7 is a mark for various special use occasions or additional special use requirements, marked with a pinyin letter after “-“. Sometimes in order to highlight this item, write this item to the top. Such as ZR- (flame retardant), NH- (fire-resistant), WDZ- (low smoke and halogen-free, corporate standard), -TH (for hot and humid areas), FY- (termite-proof, corporate standard), etc.

Analysis and Engineering Application of Fireproof Performance of Mine Cable

Due to the increase of wires and cables, the concentration of laying, the poor quality of construction, etc., the danger of wire and cable fires has increased. Therefore, to prevent aerial bundled cable astm b231 fires in actual engineering applications, it is necessary to start with controlling dangerous factors, apply relevant regulations, and take corresponding fire prevention measures.

1 Fire causes and characteristics of wires and cables

Mainly because of overload, short circuit, excessive contact resistance and external heat source. Causes of fire caused by wires and cables under fault conditions such as short circuit, local overheating and external heat. Insulation materials decrease in insulation resistance, lose insulation ability, or even burn, which may cause a fire. The main characteristics of wires and cables in fire are:

In case of fire, the fire temperature is generally 800℃~1000℃. Wires and cables will quickly lose their insulating ability, which will cause secondary electrical accidents such as short circuits and cause greater losses;

2 The conductor cable has a larger overload capacity under the specified allowable current carrying capacity;

The wire and cable will cause the insulation material to melt and burn in an instant, 3 short-circuit conditions. And ignite the surrounding combustible materials.

2 Analysis of fire performance of aerial bundled cable (abc) astm b231 standard 

2.1 Analysis of fire protection mechanism

2.1.1 Flame retardant mechanism

The flame retardant in the condensed phase decomposes and absorbs heat, and is under the heat of the combustion reaction. Slow down the temperature rise in the condensed phase and delay the thermal decomposition rate of the material;

The chain reaction free radical blocker is released, and the flame retardant is decomposed by heat. Interrupt the branches of flame and chain reaction, and slow down the speed of gas phase reaction;

The formation of the coking layer or foam layer strengthens the effect of these layered hard shells in hindering heat transfer; 3 catalyzes the thermal decomposition of the solid phase products of the condensed phase.

The flame retardant has an endothermic phase change, under the action of 4 heat. Physically prevent the temperature rise in the condensed phase.

2.1.2 Fire resistance mechanism

To reduce the heat generated by the polymer, a certain additive is added to the insulation and sheath materials of the wire and cable. Prevent polymer decomposition or promote the carbonization of insulation and sheath materials to form a maintenance layer;

After the insulation and sheath layer is eroded by fire, a layer of mica glass ribbon and other inorganic insulating materials are added to the 2 cores. *The mica refractory tape wrapped around the conductor is maintained and continues to be energized, so as to maintain normal operation for a certain period of time when a fire occurs.

2.1.3 Mechanism of mineral insulated cables

AlOH3 is 34.6% under high temperature operation, and the absorption effect of metal hydrate makes the cable flame-retardant. For example: use AlOH3 and MgOH as flame retardants. MgOHz is 31%, see Reaction Equation 1 and Reaction Equation 2, the reaction is decomposed into an endothermic reaction, which can inhibit the burning of polymers. 2A IOH3–*A lz03+3H20-2648KJ1MgOH2–MgO+H20-93.3KJ2

2.2 Classification of burning characteristics of wires and cables and their standard tests

It can be divided into ordinary wire and cable, flame-retardant wire and cable, fire-resistant wire and cable, halogen-free low-smoke wire and cable, and mineral insulated cable. Wire and cable according to their own burning characteristics.

1 Flame-retardant wires and cables refer to wires and abc cables b230 that are difficult to catch fire and have the ability to prevent or delay the spread of flame. The commonly used standard test is GBT18380. 3 is equivalent to IEC60332-1999

Wire and cable that can still maintain the integrity of the circuit. The commonly used standard test is GBT12666. 6 which is equivalent to IEC60331-21-19992 fire-resistant wire and cable means that it burns under a flame at a specified temperature and time.

When burning, it produces less smoke and has wires and cables that prevent or delay the spread of flames. Commonly used standard tests are GBT17650. 2 is equivalent to IEC60754-2, GBT17651. 2 is equivalent to IEC61034-2 and GBT18380. 3 is equivalent to EC60332-3. On the basis of the above, the flame-retardant and fire-resistant type also need to meet the requirements of maintaining the integrity of the line. 3 There are two types of halogen-free and low-smoke wires and cables. Flame-retardant type means that the material does not contain halogen. At the same time, the commonly used standard test adds GBT12666. 6 is equivalent to IEC60331

How to distinguish between national standard wires and inferior non-standard wires

Before moving into a new house, everyone will check the house first, but most citizens will focus on the structure of the house, and they rarely care about the wires inside the walls. If the house is compared to a person, then the wires hidden in the walls are the vital “arteries”. The wires for home improvement not only concern the normal daily life of the family, but also the safety of the family’s relatives. Inferior wires may cause short circuits, Electric shock, damage to electrical equipment, and even fire, causing casualties. Nowadays, a large number of non-standard wires and low-quality counterfeit wires are flooding the building materials market. Some low-quality wires are broken as soon as they are twisted, making it easier to distinguish. But some low-quality wires are exquisite in workmanship, and at first glance they seem to be even better than the national standard! How to distinguish between national standard wires and inferior non-standard wires? Huaxing Cable‘s professional electrician technicians suggest that you should never think about saving money when buying home improvement wires. The quality of the wires not only affects the service life and safety of household appliances associated with them, but also affects the life safety of our family members. Now let the professional electrician technician of the cable explain to you how to distinguish between the national standard wire and the inferior non-standard wire!

The first step in identifying wires: look at the wire signsThe national standard wire label is the product qualification certificate. Take the wire qualification certificate as an example, it is printed with: wire product trademark, wire product name, wire manufacturer name, wire production site, cable manufacturer contact number, CCC certification and aerial bundled cable b230 factory number, wire model specification , National standard, rated voltage, length of wire, cross-sectional area of ​​wire conductor, production date, inspector’s seal. At the same time, well-known brand wire manufacturers generally have anti-counterfeiting labels that cannot be imitated! Each coil of the aerial bundled cable(abc) b231  has an anti-counterfeit QR code and a barcode, double anti-counterfeiting, just like our ID number

Inferior non-marking signs do not have the above content or are incomplete, and even if they have, they cannot be investigated. The following low-quality line signs are taken as an example; the trademark and company name are all virtual, although the factory address is available, but not specific, there is no way to find the phone number, the model column is blank, and the specification column is only marked 2.52. The formal marking should It is the number of conductor cores × conductor diameter, that is, 1×1.78 mm. The inspector’s seal is printed together with the other contents of the sign, which means that there is no need for inspection at all, and there is no anti-counterfeiting label.

The second step is to look at the copper wire conductor

Qualified copper core wires should be oxygen-free copper, purple-red, shiny, and soft to the touch.

The fake and inferior copper core wire is purple-black, yellowish or white, with many impurities, poor mechanical strength, poor toughness, and it will break with a little force, and there are often disconnections in the wire. The picture below is a low-quality copper-clad copper wire.

The third step is to look at the insulation material

The insulating layer of the national standard wire is made of high-quality insulating plastic, which has a certain degree of mechanical strength and flexibility, and cannot be torn easily. The insulating layer of high-quality wires has a certain flame retardancy. Peel off a section of the national standard wire insulation layer and ignite it with a lighter. After leaving the open flame, it can self-extinguish, and the smoke is light and has a light smell.

The insulating layer of inferior non-standard wire is made of recycled plastic, which has poor insulating ability, which can easily cause the insulating layer to be broken down by current and leak. Great harm to the life safety of users! Inferior wires can be distinguished from the insulating layer with a little attention. Pull off a section of the insulating layer. As shown in the figure below, if the color of the cross section is white, it is the inferior wire. Fold a certain part of the wire several times in succession. If the color of the folded part turns white, it can be judged. It is a low-quality wire. Use a lighter to carry out the igniting experiment, it can still burn after leaving the open flame, and the smoke has a strong smell. Cut a section of the wire insulation layer to see if there are visible pores in the section of the insulation layer and whether the core is located in the middle of the insulation layer. What is not in the center is the eccentricity caused by the low craftsmanship. The presence of pores indicates that the wire insulation material used is unqualified. Severe eccentricity is most likely to leak electricity on the thinner side, and air holes also affect the compressive strength of the wire.

The advantages of copper core cable and aluminum core cable are compared

Copper core cables have more advantages than aluminum core cables:

1. Low resistivity: the resistivity of aluminum core aerial bundled cable BS 7870 is about 1.68 times higher than that of copper core cable.

2. Good ductility: the ductility of copper alloy is 20-40%, the ductility of electrical copper is more than 30%, while aluminum alloy is only 18%.

3. High strength: the allowable stress at room temperature, copper is 7~28% higher than aluminum. Especially the stress at high temperature, the difference between the two is even greater.

4. Anti-fatigue: Aluminum is easy to break after repeated bending, while copper is not easy. In terms of elasticity index, copper is also about 1.7-1.8 times higher than aluminum.

5. Good stability and corrosion resistance: The copper core is resistant to oxidation and corrosion, while the aluminum core is susceptible to oxidation and corrosion.

6. Large current carrying capacity: Due to the low resistivity, the copper core cable of the same cross section is about 30% higher than the allowable current carrying capacity (the maximum current that can pass) of the aluminum core cable.

7. Low voltage loss: Due to the low resistivity of the copper core cable, the same current flows in the same section. The voltage drop of the copper core cable is small. Therefore, the same transmission distance can ensure higher voltage quality; in other words, under the allowable voltage drop condition, the copper core cable can reach a longer distance, that is, the power supply coverage area is large, which is beneficial to network planning and reduces The number of power supply points.

8. Low heating temperature: Under the same current, the copper core cable with the same cross section has much smaller heat than the aluminum core cable, which makes the operation safer.

9. Low energy consumption: Due to the low electrical resistivity of copper, it is obvious that copper cables have low power loss compared to aluminum cables. This is conducive to improving the utilization rate of power generation and protecting the environment.

10. Anti-oxidation and corrosion resistance: The performance of the connector of the copper aerial bundled cable(ABC) B231 is stable, and there will be no accidents due to oxidation. When the connector of aluminum core cable is unstable, the contact resistance will increase due to oxidation and heat will cause accidents. Therefore, the accident rate is much greater than that of copper core cables.

11. Convenient construction: The copper core is flexible and the allowable bend radius is small, so it is convenient to bend and easy to pass through; the copper core is fatigue-resistant, repeated bending is not easy to break, so the wiring is convenient; the copper core has high mechanical strength and can withstand relatively The large mechanical pulling force brings great convenience to construction and laying, and also creates conditions for mechanized construction.

12. Cheap price: Copper pole is 3.5 times the price of aluminum pole, and the proportion of copper is 3.3 times that of aluminum. Therefore, aluminum core cables are much cheaper than copper core cables, and are suitable for low-cost projects or temporary electricity use.

13. The cable is very light: the weight of the aluminum core cable is 40% of the copper core cable, and the construction and transportation costs are low.

14. Anti-oxidation and corrosion resistance: Aluminum quickly reacts with oxygen in the air to form an oxide film, which can prevent further oxidation. Therefore, aluminum wire is a necessary material for high-voltage, large-section, and large-span overhead power transmission.

Although aluminum core cables are cheap, copper cables have outstanding advantages in cable power supply, especially in the field of underground cable power supply. The underground power supply using copper core cables has the characteristics of low accident rate, corrosion resistance, high reliability, and convenient construction and maintenance. This is why copper abc cables are mainly used in underground power supply in China.

Analysis and Treatment of 35kV Cross-linked Cable Water Ingress

Cross-linked polyethylene insulated cables have good mechanical properties, convenient installation and maintenance, excellent insulation performance, larger transmission capacity than oil-paper insulated cables of the same cross-section, simple production process, conducive to mass production, and can transmit power to areas that cannot be reached by overhead lines And other advantages, so it is increasingly widely used in power systems and constitutes an important part of the transmission and distribution network.

Cross-linked polyethylene insulated cables can choose a variety of laying methods according to engineering conditions, environmental characteristics, cable type and quantity, combined with the requirements of reliable operation, easy maintenance, and the principle of reasonable technology and economy, such as direct buried laying, pipe laying, Shallow trench laying, trench laying, tunnel laying, etc. The use of buried aerial bundled  cables ASTM B231 to realize the power transmission and connection between two or more electrical devices can save space and line corridors and reduce the consumption of valuable land resources. The selection of qualified cables and accessories, laying and installation in accordance with the requirements of standards and specifications, and strict guarantee of construction quality are the prerequisite and guarantee for the safe and reliable operation of cable lines.

1. Water ingress analysis inside the cable

Analysis of Causes of Water Ingress As the complete new cable adopts multiple waterproof and water-blocking designs in the internal structure and materials, there will be no internal water ingress under the condition that the two ends are sealed. Aiming at the cause of water ingress into the 35 kV cable, this article conducts an in-depth analysis in connection with the cable manufacturing, transportation, laying and installation links:

(1) Water enters during the production of ABC ASTM B231. The main production process of the cable supplier is: first, a single compact conductor core is formed by wire drawing and twisting; then the conductor semi-conductive shield, XLPE insulation and insulated semi-conductive shield are simultaneously extruded on the outside; then winding Protective tape and metal shielding layer; combine the three cable cores and add fillers to form a cable; wrap the inner sheath and armored steel tape on the outside of the three-core cable, and finally squeeze a layer of polyvinyl chloride outer sheath. In order to control the quality of cable production, the manufacturer adopts many methods in the production process to prevent moisture from penetrating into the cable. For example, advanced production equipment is used to achieve three-layer co-extrusion of conductor semi-conductive shielding, insulation, and insulating semi-conductive shielding; XLPE insulation adopts dry The cross-linking method performs cross-linking. If you strictly abide by the entire production process, with the current advanced technology and production equipment, there will be no water ingress into the cable when manufacturing cross-linked cables.

(2) Water ingress during transportation and construction. There are three possible situations when water enters the cable: one is that the outer sheath of the cable is broken during transportation and installation, and it is exposed to rain or water so that water enters the outer sheath of the cable; the other is that the cable is accidentally used during construction. The head is damaged and water has entered. The third is that when it rains during installation, construction workers forget to cover the sawn cable ports, causing rainwater to flow into the cables.

1.2 Analysis of the influence of water ingress In the first case, water enters the inside of the cable through the crack in the outer sheath, and the steel strip of the armor layer will quickly rust, and then the water will penetrate into the filling material to make it absorb water and become damp. The phase-to-phase insulation of the cable has an impact, but has little effect on the single-phase insulation. In the second and third cases, water can directly enter the bare conductor. If you cut the cable conductor core and observe its cross section, you will find that there is water flowing out of the multi-strand core. If the incoming water is not cleaned up in time, after the cable is energized, water branches can be generated on the side of the main insulation close to the conductor core, which will lead to the generation of branches, and finally lead to the breakdown of the main insulation. Because of the serious consequences of water ingress in the cross-linked cable, as long as water in the cross-linked cable is found, immediately stop laying and installation, analyze the cause of the water in detail, find out the aerial bundied cable(ABC)  damage as soon as possible, and take appropriate measures to deal with it in time.