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The main reason for using fumigated wooden drums for cable exports 1. Comply with international quarantine requirements • Regulatory compliance: Most countries/regions in the world have formulated strict quarantine regulations to prevent wooden packaging from carrying harmful organisms (pests, eggs, pathogens, etc.) to cause biological invasion or spread of plant pests and diseases. • Core measures: Fumigation treatment can kill harmful organisms in wooden drums, ensure that the goods pass the quarantine of the importing country, and avoid the risk of return or destruction. 2. Protect cable products • Structural advantages: The wooden drum is made of strong material, providing stable support for the cable, and resisting mechanical damage such as collision and extrusion during transportation and loading and unloading. • Environmental adaptability: The natural moisture-proof and buffering properties of wood reduce the impact of humidity, vibration, and other external environments on the cable insulation layer and outer sheath. 3. Easy to transport and load, and unload • Standardized design: The specifications of the fumigated wooden drums are unified (such as diameter and load-bearing parameters), which are suitable for cable winding and fixing, and improve the efficiency of storage and stacking. •Mechanized operation: The regular shape facilitates forklift and crane operation, reduces manual handling losses, and optimizes logistics space utilization. IV. Environmental sustainability •Material characteristics: Wood is a renewable resource and can be recycled after use, which is in line with the global green packaging trend. •Comparative advantages: It is lower carbon than disposable plastic/metal packaging and reduces waste disposal costs.

Dear customers and partners, In celebration of International Workers' Day, our company will observe a holiday from May 1st to May 5th, 2025, a total of five days. Our office will resume normal operations on May 6th. During this period, our customer service will be unavailable. We will process them as soon as we return to work. For any urgent matters, please contact us at worldmarket@zhenglancable.com. We apologize for any inconvenience caused by the holiday and wish you a wonderful May Day!   Best Regards.                                                                                                                                                                             Zhenglan Cable Technology CO., Ltd

The main differences between pure copper grounding wire and copper-clad steel grounding wire are material composition, conductivity, corrosion resistance and applicable scenarios. ‌ 1. Material composition ‌Pure copper grounding wire‌: Made of pure copper, with a copper content of up to 99.95%, it has good conductivity and corrosion resistance‌ ‌Copper-clad steel grounding wire‌: It is composed of a high-strength steel core and a copper layer, and the thickness of the copper layer is generally above 0.25mm‌   2.Conductive performance ‌Pure copper grounding wire‌: Excellent conductivity, low resistivity, able to quickly conduct current and maintain a low grounding resistance value‌ ‌Copper-clad steel grounding wire‌: High resistivity, relatively poor conductivity, but in some cases, its corrosion resistance is relatively good Strong ‌   3. Corrosion resistance ‌ Pure copper grounding wire‌: Due to the high copper content, it has strong corrosion resistance, but requires better protection under complex grounding conditions ‌ Copper clad steel grounding wire‌: Weak corrosion resistance, prone to inner layer corrosion ‌   4. Applicable scenarios ‌ Pure copper grounding wire‌: Suitable for occasions with high safety requirements, such as large facilities such as power stations, to ensure the safety of the facilities ‌ Copper clad steel grounding wire‌: Suitable for small facilities, such as household electricity, small factories, etc., because of its low cost and guaranteed use effect ‌

‌Places with harsh environmental conditions‌: In places with harsh environmental conditions, such as high temperature, humidity, and corrosive environments, category 5 soft power cables can better adapt to these environments due to their softness and corrosion resistance, ensuring the stable operation of the cables.   ‌Equipment that needs to be moved frequently‌: For equipment that needs to be moved frequently, such as temporary construction sites, event stages, etc., the softness and flexibility of category 5 soft power cables make it easier to install and disassemble, reducing restrictions on equipment.   ‌Wiring in narrow spaces‌: When wiring in narrow spaces, category 5 soft power cables are easier to pass through narrow spaces due to their softness, meeting complex wiring requirements. ‌Equipment that needs to be frequently replaced or upgraded‌: In situations where equipment needs to be frequently replaced or upgraded, choosing category 5 soft power cables can reduce the difficulty and cost of wiring because they are easy to install and disassemble.   ‌Occasions with special requirements for cable softness‌: In some special applications, such as robots, automation equipment, etc., there are high requirements for cable softness and flexibility, and category 5 soft power cables can meet these requirements

Keywords: Cable insulation, PVC, XLPE, electrical safety, power transmission In the world of electrical cables, insulation plays a crucial role in ensuring safety and efficiency. It prevents electrical leakage, protects against environmental factors, and enhances the durability of cables. Today, we will explore the most commonly used insulation materials: PVC (Polyvinyl Chloride) and XLPE (Cross-linked Polyethylene). PVC Insulation PVC is a widely used material in low-voltage power cables, control cables, and household wiring. It is flexible, cost-effective, and resistant to moisture and chemicals. However, PVC has a lower temperature tolerance compared to other materials, making it suitable for applications where excessive heat is not a concern. XLPE Insulation XLPE offers superior electrical properties and higher thermal resistance. It is commonly used in medium and high-voltage power cables, ensuring reliable performance even in harsh conditions. Its excellent insulation capacity allows cables to carry higher currents without overheating. Choosing the Right Insulation Selecting the right insulation material depends on the operating environment and voltage level. For general wiring and low-voltage applications, PVC is an economical choice. However, for industrial and power transmission applications, XLPE provides better long-term performance and reliability. Understanding these differences helps in making informed decisions when selecting cables for various applications. If you need expert advice on choosing the right cable for your project, feel free to contact us!

In the design and construction of power systems, cable selection is a core link related to safety and efficiency. However, if a cable with a small cross-sectional area is selected due to cost control or lack of experience, the following major hidden dangers may be buried: 1. Overheating and fire: the silent "invisible killer" Joule thermal effect is out of control: insufficient cross-sectional area leads to increased conductor resistance, and excessive heat is generated when current passes through (Q=I²R). If the heat dissipation conditions are poor, the cable temperature rises sharply, and the insulation layer may carbonize, melt or even burn. 2. Voltage drop: "chronic poisoning" of equipment, power supply quality collapse at the end: when transmitting power over long distances, too small a cross-sectional area causes the line voltage drop to exceed the standard (ΔU=IR). At the least, the lights flicker, the motor speed is unstable, and, at the worst, the precision equipment shuts down. 3. Life loss: 90% of the faults are caused by this accelerated insulation aging: long-term overload operation increases the thermal aging rate of insulation materials by 3-5 times. Cables originally designed for a lifespan of 25 years may be at risk of breakdown within 5 years. Maintenance costs doubled: Once an underground cable fails, the excavation and repair costs can be more than 10 times the original cost. 4. Energy waste: The Invisible "black hole" line loss devours profits: If the cross-sectional area is reduced by 50%, the resistance loss will double. If a 500-meter-long 380V line is selected incorrectly, the annual power loss may exceed 20,000 kWh, which is equivalent to throwing away tens of thousands of yuan in electricity bills. 5. Legal liability: If an accident occurs, you will be held responsible. Insurance denial trap: Most engineering insurance clearly excludes losses caused by "design errors", and companies may face huge out-of-pocket compensation. How to avoid selection disasters? Accurately calculate load current: Consider correction factors (K value) such as harmonics, ambient temperature, and laying methods Dynamic planning margin: reserve 15%-25% capacity to cope with future expansion needs Full life cycle Cost analysis: Saving 10,000 yuan in cable fees in the early stage may mean 100,000 yuan in maintenance costs in the later stage Electrical safety is not a fluke, and the essence of cable selection is the designer's calculation of awe for life. When each conductor's cross-sectional area accurately matches the safety requirements, we can truly build a copper wall to protect the light.

In recent years, the technology of the photovoltaic industry has developed faster and faster. The power of a single module is getting bigger and bigger, and the current of the string is getting bigger and bigger. The current of high-power modules has reached more than 17A. In terms of system design, the use of high-power components and reasonable reserved space can reduce the initial investment cost and kilowatt-hour cost of the system. The cost of AC and DC cables in the system is not low. How should we design and select to reduce costs?   1. Selection of DC cables DC cables are installed outdoors. It is generally recommended to select irradiated and cross-linked photovoltaic cables. After high-energy electron beam irradiation, the molecular structure of the cable insulation material changes from a linear type to a three-dimensional mesh molecular structure, and the temperature resistance level increases from 70℃ for non-cross-linked cables to 90℃, 105℃, 125℃, 135℃, and even 150℃, which is 15-50% higher than the current carrying capacity of cables of the same specification. It can withstand drastic temperature changes and chemical erosion and can be used outdoors for more than 25 years. When choosing a DC cable, you should choose a product with relevant certification from a regular manufacturer to ensure long-term outdoor use. The most commonly used photovoltaic DC cable is the 4-square cable of PV1-F1*4, but with the increase in the current of photovoltaic modules and the increase in the power of a single inverter, the length of the DC cable is also increasing, and the application of 6 square meters of DC cables is also increasing.   According to relevant specifications, it is generally recommended that the loss of photovoltaic DC should not exceed 2%. We use this standard to design how to choose DC cables. The line resistance of PV1-F1*4mm² DC cable is 4.6mΩ/meter, and the line resistance of PV6mm² DC cable is 3.1mΩ/meter. Assuming the working voltage of the DC component is 600V, the 2% voltage drop loss is 12V. Assuming the component current is 13A, using 4mm² DC cable, the distance between the farthest end of the component and the inverter is recommended not to exceed 120 meters (single string, excluding positive and negative poles). If it is greater than this distance, it is recommended to select a 6mm² DC cable, but it is recommended that the distance between the farthest end of the component and the inverter should not exceed 170 meters.   2. Calculation of photovoltaic cable line loss To reduce system costs, the components and inverters of photovoltaic power stations are rarely configured in a 1:1 ratio but are designed with a certain over-matching according to lighting conditions, project needs, etc. For example, for a 110KW module, a 100KW inverter is selected. According to the calculation of 1.1 times the over-matching of the inverter AC side, the maximum AC output current is about 158A. The AC cable can be selected according to the maximum output current of the inverter. Because no matter how many components are configured, the AC input current of the inverter will never exceed the maximum output current of the inverter.   3. Inverter AC output parameters Commonly used photovoltaic system AC copper cables include BVR and YJV. BVR means copper core polyvinyl chloride insulated soft wire, YJV cross-linked polyethylene insulated power cable. When selecting, pay attention to the voltage level and temperature level of the cable. Flame-retardant type should be selected. Cable specifications are expressed by the number of cores, nominal cross-section, and voltage level: single-core branch cable specification expression method, 1*nominal cross-section, such as 1*25mm 0.6/1kV, indicating a 25 square cable. Multi-core twisted branch cable specification expression method, the number of cables in the same loop*nominal cross-section, such as 3*50+2*25mm 0.6/1KV, indicating 3 *50 square live wires, 1* 25 square neutral wire, and 1* 25 square ground wire.

Polyvinyl chloride insulated power cables: Polyvinyl chloride plastics are cheap, have good physical and mechanical properties, and have simple extrusion processes, but their insulation properties are average. They are used in large quantities to manufacture low-voltage power cables of 1 kV and below for use in low-voltage distribution systems. If insulating materials with voltage stabilizers are used, 6 kV cables can be produced.   Cross-linked polyethylene insulated power cables: Good electrical properties, mechanical properties and heat resistance. In the past two decades, it has become the leading variety of medium and high voltage power cables in my country, and can be used in various voltage levels from 6 to 330 kV. In recent years, cross-linking of 1 kV low-voltage cables has become a technical direction. The key is to reduce the insulation thickness so that it can compete with polyvinyl chloride cables in terms of price.   Viscous oil-impregnated insulated power cables: They were the leading products of medium-voltage cables in my country before 1992. This is a classic structure of power cables with a history of more than 100 years, with large electrical and thermal performance margins and long service life. Oil-filled cable: suitable for 66-500 kV. Rubber insulated power cable: a soft, movable power cable, mainly used in places where enterprises often need to change the laying position. Natural rubber insulation is used, the voltage level is mainly one kV, and 6 kV level can be produced. Overhead insulated cable: essentially an overhead conductor with insulation, the insulation can be made of polyvinyl chloride or cross-linked polyethylene. Generally made into a single core, or 3-4 phase insulated cores can be twisted into a bundle without sheath, which is called a bundled overhead cable.   Characteristics of power cables:   Compared with other overhead bare wires, its advantages are less affected by external climate, most reliable, concealed, less maintenance, durable, and can be laid in various occasions. However, the structure and production process of power cables are relatively complex and the cost is relatively high.   Different specifications, but all have the following characteristics and manufacturing requirements:   The working voltage is high, so the cable is required to have excellent electrical insulation performance.   The transmission capacity is large, so the thermal performance of the cable is more prominent.   Since most of them are fixedly laid in various environmental conditions (underground, tunnel trenches, shaft slopes, and underwater, etc.), and require reliable operation for decades, the requirements for sheath materials and structures are also high.   Due to changes in factors such as power system capacity, voltage, number of phases, and different laying environmental conditions, the varieties and specifications of power cable products are also quite numerous. According to the strong electrical characteristics of power cable applications, the consideration of its electrical and mechanical properties is relatively prominent.

The designation codes in different country for different type of cable are different in each country. Below are parts of the Designation Codes for cable designation in Germany.   Reference standards DIN VDE 0292 Type Designation Codes for cable designation DIN VDE 0293-308 Identification of the cores of cables / wires and flexible wires by colors Standard series DIN VDE 0281 for PVC-insulated cables Standard series DIN VDE 0282 for rubber insulated cables Designation Codes for Plastic insulated Power Cables Power cables with plastic insulation and plastic sheath according to DIN VDE 0262, DIN VDE 0263, DIN VDE 0265, DIN VDE 0266, DIN VDE 0267, DIN VDE 0271, DIN VDE 0273 and DIN VDE 0276 part 603, 604, 620, 622, 626 For cables with plastic insulation and plastic sheath the following designation codes are used (starting with the conductor): Code Description N Cables acc. to standard A Aluminum conductor Y Insulation of polyvinyl chloride (PVC) 2Y Insulation of thermoplastic polyethylene (PE) X Insulation of cross-linked polyvinyl chloride (XPVC) 2X Insulation of cross-linked polyethylene (XLPE) H Field limiting conductive layers over the conductor and over the Insulation HX Insulation of cross-linked halogen-free polymer blend C Concentric conductor of copper CW Concentric conductor of copper, waveform (ceander) CE Concentric conductor in multi-core cables on each individual core S Braided copper SE For multicore cables field limiting conductive layers over the conductor and the insulation and copper screen over each individual core (indicated by “H” is omitted here) F Overhead line cable (DIN VDE 0276) F Armouring of galvanized flat steel wire FE insulation sustaining (F) Longitudinally watertight cable (screen) B Steel tape armouring R Armouring of galvanized round steel wires G Helix of galvanized steel tape HX Sheath of cross-linked halogen-free polymer blend Y Inner sheath of polyvinylchloride (PVC) Y Outer sheath of polyvinylchloride (PVC) 2Y Outer sheath of polyethylene (PE) 1Y Outer sheath of polyurethane (PUR)   Conductor cross-section, shape and structure Code Description R Circular conductor S Sector shaped conductor E Solid conductor M Stranded conductor RE Circular conductor, solid RM Circular conductor, stranded SE Sector shaped conductor, solid SM Sector shaped conductor, stranded OM Oval shaped conductor, stranded H Waveguide /V Compacted conductor  

Dear Customers,   Please be informed that our company will be closed from January 26th to February 4th for the Chinese New Year holiday. Normal business will resume on February 5th We're sorry for any inconvenience that occurred please do drop us an email at worldmarket@zhenglancable.com or call us if you have urgent matters. We would like to express our heartiest thanks for your great support and cooperation. Wishing you a prosperous year in 2025!   Zhenglan Cable Technology CO., Ltd.

  In practical applications, the design of compressed copper conductors needs to consider many factors, including compression coefficient, stranding structure, material resistivity, etc.   For example, for a 95 mm² compressed copper conductor, its kilometer resistance should not exceed 0.193Ω/km, which needs to be achieved through a reasonable stranding structure and single wire diameter.   The compression process will increase the resistivity of the conductor, so it is necessary to introduce corresponding correction factors during design, such as compression coefficient K3 and stranding coefficient K2, to ensure that the final resistance value meets the standard requirements.     The relationship between the cross-sectional area and DC resistance of compressed copper conductors can be summarized by the following points: 1. Inverse relationship: The cross-sectional area A is inversely proportional to the DC resistance R, that is, the larger the cross-sectional area, the smaller the DC resistance. 2. Compression effect: The compression process will cause the conductor to harden, thereby increasing the resistivity, which needs to be adjusted through the correction factor. 3. Design requirements: According to national standards (such as GB/T3956), the DC resistance value of the conductor is the key indicator to measure its qualification, and the cross-sectional area is only the basis for design and calculation. 4. Adjustment in practical application: In the production process, in order to reduce costs, the cross-sectional area may be reduced to the minimum value to meet the DC resistance requirements, but this practice may affect the overall performance of the cable.   Therefore, when designing and manufacturing compressed copper conductors, it is necessary to comprehensively consider factors such as cross-sectional area, compression coefficient, and material resistivity to ensure that the DC resistance of the conductor meets the standard requirements and meets the performance requirements in practical applications.   The specific calculation method of the compression coefficient K3 and twisting coefficient K2 of the compressed copper conductor is as follows: Compression coefficient K3： Compression coefficient K3 refers to the ratio of the actual cross-sectional area of ​​the conductor after compression to the theoretical cross-sectional area when not compressed. According to the evidence, the value of the compression coefficient is usually 0.90, which is empirical data based on production experience and process tests.   Twisting coefficient K2 ： The twisting coefficient K2 refers to the ratio of the actual length of a single wire to the length of the twisted wire pitch within a twist pitch. Other related parameters 1. Single wire diameter: For stranded conductors with a single wire diameter greater than 0.6 mm, K2 is 1.02; for stranded conductors with a single wire diameter not greater than 0.6 mm, K2 is 1.04. 2. Cabling coefficient: For single-core and non-cabled multi-core cables, it is 1, and for cabled multi-core cables, it is 1.02.   In summary, the specific calculation method of the compaction coefficient K3 and twisting coefficient K2 of compacted copper conductors is as follows: Compressive coefficient K3: Usually the value is 0.90.

Dear Customer,   Thanks for your support in the past year. We cannot make even a little progress in our business without your attention. That's why we never forget the past.    Here comes the new year. We send our blessings to you. May your year be filled with love, laughter, and endless possibilities. May your journey through 2025 be filled with adventure, joy, and wonder.   Happy New Year!!   Zhenglan Cable Technology Co., Ltd.

Dear Customer   Thank you for visiting our website.   Upon the Christmas May your Christmas be filled with love, laughter, and the warmth of family and friends. May your holiday be as wonderful as you are, filled with love, joy, and festive cheer.   Merry Christmas!   Zhenglan Cable Technology Co., Ltd

Flame-retardant wire refers to wires that are fireproof and flame-retardant. Generally, under test conditions, after the wire is burned, if the power is cut off, the fire will be controlled within a certain range and will not spread. It has the performance of flame retardancy and suppression of toxic smoke. As an important part of electrical safety, the selection of materials for flame-retardant wires is crucial. At present, the commonly used flame-retardant wire materials on the market include PVC, XLPE, silicone rubber, and mineral insulation materials. Material selection of flame-retardant wires and cables The higher the oxygen index of the material used for flame-retardant cables, the better the flame-retardant performance, but as the oxygen index increases, some other properties will be lost. If the physical properties and process properties of the material are reduced, the operation is difficult, and the material cost is increased, so the oxygen index should be reasonably and appropriately selected. Generally, if the oxygen index of the insulating material reaches 30, the product can pass the test requirements of Class C in the standard. If the sheath material and the filling material are both flame-retardant materials, the product can meet the requirements of Class B and Class A. Materials for flame-retardant wires and cables are mainly divided into halogen-containing flame-retardant materials and halogen-free flame-retardant materials;   1. Halogen-containing flame-retardant materials decompose and release hydrogen halides when heated during combustion. Hydrogen halides can capture active free radicals HO roots, thereby delaying or extinguishing the combustion of the material and achieving the purpose of flame retardancy. Commonly used materials include polyvinyl chloride, chloroprene rubber, chlorosulfonated polyethylene, ethylene propylene rubber, etc. 1) Flame-retardant polyvinyl chloride (PVC): Due to its low price, good insulation, and flame retardancy, polyvinyl chloride is widely used in ordinary flame-retardant wires and cables. To improve the flame retardancy of PVC, halogen flame retardants (decabromodiphenyl ether), chlorinated paraffin, and synergistic flame retardants are often added to the formula to improve the flame retardancy of polyvinyl chloride; Ethylene propylene rubber (EPDM): It is a non-polar hydrocarbon with excellent electrical properties, high insulation resistance and low dielectric loss, but EPDM is a flammable material. It is necessary to reduce the degree of cross-linking of EPDM and reduce the low molecular weight substances produced by molecular chain disconnection to improve the flame retardancy of the material; 2) Low smoke and low halogen flame retardant materials are mainly for polyvinyl chloride and chlorosulfonated polyethylene. Add CaCO3 and A(lOH)3 to the formula of polyvinyl chloride. Zinc borate and MoO3 can reduce the HCL release and smoke of flame-retardant polyvinyl chloride, thereby improving the flame retardancy of the material and reducing the emission of halogen, acid mist and smoke, but may slightly reduce the oxygen index.   2. Halogen-free flame retardant materials Polyolefin is a halogen-free material composed of hydrocarbons. It decomposes carbon dioxide and water when burned, and does not produce obvious smoke and harmful gases. Polyolefins mainly include polyethylene (PE) and ethylene-vinyl acetate (E-VA). These materials themselves are not flame retardants, and inorganic flame retardants and phosphorus series flame retardants need to be added to be processed into practical halogen-free flame retardant materials; however, due to the lack of polar groups on the molecular chain of non-polar substances, they are hydrophobic and have poor affinity with inorganic flame retardants, making it difficult to combine firmly. To improve the surface activity of polyolefins, surfactants can be added to the formula; or polymers containing polar groups can be mixed into polyolefins for blending, thereby increasing the amount of flame retardant fillers, improving the mechanical properties and processing properties of the material, and obtaining better flame retardancy. It can be seen that flame-retardant wires and cables are still very advantageous and are very environmentally friendly to use.

Shielded cable is a cable used to transmit signals. It has shielding properties and is used to prevent external electromagnetic interference from affecting its transmission effect. It usually has a conductive shielding layer to isolate or absorb the radiation of external electromagnetic fields. 1. Metal shielding Metal shielding is a shielding method mainly used for high-frequency signal transmission. It usually includes two forms: copper foil shielding and copper mesh shielding. Copper foil shielding is to wrap copper foil around the insulator and core wire to form a shielding layer around the entire wire. Copper mesh shielding is to weave copper wire into a mesh and put it on the outer layer of the wire. Its shielding performance is slightly inferior to copper foil shielding. 2. Aluminum-plastic composite shielding Aluminum-plastic composite shielding refers to the inner core wire covered with a layer of aluminum-plastic composite material, the outer layer is aluminum foil, and the inner layer is plastic film. Aluminum-plastic composite shielding can achieve a good shielding effect, and has the good electrical properties of the outer layer of aluminum foil and the protective effect of the inner layer of plastic film, especially suitable for low-frequency signal transmission. 3. Copper tape shielding Copper tape shielding is to wrap a layer of copper tape around the outside of the core wire, which can achieve shielding of external electromagnetic fields through grounding. Copper tape shielding has a better shielding effect and is suitable for occasions where both high-frequency and low-frequency signals are transmitted. In short, the application range of shielded cables is becoming more and more extensive. Its different shielding methods are suitable for different transmission frequencies and occasions. Users need to choose cables according to their specific application requirements. Different shield has different functions. Please choose as per your own situation.

1.1 The selection of cable insulation type shall comply with the following provisions: 1 Under the operating voltage, working current and its characteristics and environmental conditions, the cable insulation characteristics shall not be less than the normal expected service life. 2 It shall be selected based on factors such as operational reliability, ease of construction and maintenance, and the comprehensive economy of the maximum allowable operating temperature and cost. 3 It shall meet the requirements of fire-proof places and shall be conducive to safety. 4 When it is clear that it needs to be coordinated with environmental protection, environmentally friendly cable insulation types shall be selected. 1.2 The selection of insulation types for commonly used cables shall comply with the following provisions: 1 The selection of insulation types for medium and low voltage cables shall comply with the provisions of Articles 1.3 to 1.7 of this Code. Low voltage cables shall use polyvinyl chloride or cross-linked polyethylene extruded insulation types, and medium voltage cables shall use cross-linked polyethylene insulation types. When it is clear that it needs to be coordinated with environmental protection, polyvinyl chloride insulated cables shall not be used. 2 Cable lines in high-voltage AC systems shall use cross-linked polyethylene insulation types. In areas with more operating experience, self-contained oil-filled cables can be used. 3 For high-voltage direct current transmission cables, non-drip-impregnated paper insulation and self-contained oil-filled types can be selected. When it is necessary to increase the transmission capacity, it is advisable to select a type constructed with semi-synthetic paper materials. Ordinary cross-linked polyethylene cables should not be used for direct current transmission systems. 1.3 For mobile electrical equipment and other circuits that are often bent or have high flexibility requirements, rubber insulation and other cables should be used. 1.4 In places where radiation is applied, cables with radiation irradiation strength such as cross-linked polyethylene or EPDM insulation should be selected according to the requirements of the insulation type. 1.5 In places with high temperatures above 60°C, heat-resistant cables such as heat-resistant polyvinyl chloride, cross-linked polyethylene or EPDM insulation should be selected according to the requirements of the high temperature, its duration and the insulation type; in high-temperature environments above 100°C, mineral insulated cables should be selected. Ordinary polyvinyl chloride insulated cables should not be used in high-temperature places. 1.6 In low-temperature environments below -15°C, cross-linked polyethylene, polyethylene insulation, and cold-resistant rubber insulation cables should be selected according to the low-temperature conditions and insulation type requirements. Polyvinyl chloride insulated cables should not be used in low-temperature environments. 1.7 In crowded public facilities and places with low-toxic flame retardancy and fire protection requirements, cross-linked polyethylene or ethylene-propylene rubber and other halogen-free insulated cables can be used. When low toxicity is required for fire protection, polyvinyl chloride cables should not be used. 1.8 Except for the cases required by Articles 1.5 to 1.7 of this Code, polyvinyl chloride insulated cables can be used for circuits below 6kV. 1.9 For 6kV important circuits or cross-linked polyethylene cables above 6kV, the type with the characteristics of inner and outer semi-conductive and insulating layers co-extrusion process should be selected.   The difference between polyethylene, polyvinyl chloride, cross-linked polyethylene, and ethylene-propylene rubber materials： The difference between the four materials 1. Polyethylene. English abbreviation PE, it is a polymer of ethylene, non-toxic. Easy to color, good chemical stability, cold resistance, radiation resistance, and good electrical insulation. 2. Polyvinyl chloride. English abbreviation PVC, it is a polymer of vinyl chloride. It has good chemical stability and is resistant to acids, alkalis, and some chemicals. It is resistant to moisture, aging, and flame retardant. The temperature when it is used cannot exceed 60°C (polyvinyl chloride will release toxic HCl smoke when burning), and it will harden at low temperatures. Polyvinyl chloride is divided into soft plastics and hard plastics. 3. Cross-linked polyethylene. XLPE in English is an important technology to improve the performance of PE. PE modified by cross-linking can greatly improve its performance, not only significantly improving the mechanical properties, environmental stress cracking resistance, chemical corrosion resistance, creep resistance, and electrical properties of PE, but also significantly improving the temperature resistance level, which can increase the heat resistance temperature of PE from 70°C to above 90°C, thereby greatly broadening the application range of PE. At present, cross-linked polyethylene (XLPE) has been widely used in pipes, films, wire and cable materials, and foam products. 4. Ethylene propylene rubber (EPR). The full name is cross-linked ethylene-propylene rubber, which has oxygen resistance, ozone resistance and partial discharge stability; the dielectric loss factor is large, so it is only used in power cable lines with voltage levels below 138kV. Due to the good water resistance of EPDM, EPDM cables are suitable for submarine cables, and because EPDM has good softness, it is more suitable for laying in mines and ships.

The shielding layer in the control cable has the following main functions: ‌ Electromagnetic interference suppression‌: The shielding layer can shield the electromagnetic field generated when the cable is powered on in the insulated core, reduce the electromagnetic interference to the outside world, and limit the impact of the external electromagnetic field on the inside‌.   ‌Grounding protection‌: If the cable core is damaged, the leaked current can flow into the grounding grid through the shielding layer, which plays a role in safety protection and prevents safety hazards caused by current leakage‌.   ‌Reduced signal leakage‌: The shielding layer can prevent the leakage of internal signals in the cable and prevent the signal from interfering with other nearby cables or equipment‌.   ‌Improved durability‌: The metal shielding layer can prevent the cable from physical damage, such as extrusion, stretching or bending, thereby extending the service life of the cable‌.   Zhenglan Cable can supply you with 450/750V, 0.6/1KV various equipment control cable, welcome your inquiry.  

What are the rated voltage levels of power cables, and how to determine them according to different places? 1. The rated voltage levels of power cables are mainly divided into the following categories: 1-1. Low-voltage cables: suitable for fixed laying on AC 50Hz, rated voltage 3kV, and below transmission and distribution lines for transmitting electric energy. 1-2. Medium and low voltage cables: generally refer to cables of 35kV and below, including polyvinyl chloride insulated cables, polyethylene insulated cables, and cross-linked polyethylene insulated cables. 1-3. High-voltage cables: generally 110kV and above, using polyethylene cables and cross-linked polyethylene insulated cables. 1-4. Ultra-high voltage cables: voltage levels between 275 and 800 kV. 1-5. UHV cables: voltage levels of 1000 kV and above. 2. When determining the rated voltage level of cables according to different places, the following factors need to be considered: 2-1. System nominal voltage: the rated voltage of the cable must be greater than or equal to the rated voltage of the network in which it operates. For example, if the nominal voltage of the system is 220/380V, the rated voltage of the cable should meet this requirement. 2-2. Maximum operating voltage: The maximum operating voltage of the cable shall not exceed 15% of its rated voltage. 2-3. Technical requirements: When selecting a cable model, the development of the cable industry and technical policies of various countries should be taken into account while meeting the technical requirements of the cable laying occasion.

Dear Customer Thanks for visiting our website. Due to China's National Day Holiday is coming, we will be on holiday from 1st(Tuesday) to 7th(Monday). Work resume from 8th(Tuesday). During holiday, we will have limited access to email and may reply you late. Kindly ask for your understanding. Zhenglan Cable Technology Co., Ltd September 30th, 2024

Dear Customers   Here comes Chinese traditional Mid Autumn Day festival. Kindly note we will be on a 3-day Mid-Autumn Day holiday from September 15th(Sunday) to September 17th(Tuesday). Work resume from Wednesday.    During holiday, work will stop temporarily. For all the messages you left, we wonnot be cable to reply untill after holiday. Thanks for your kind understanding. Once come back, we will contact you at our first time.   Hope everyone will have a good time.    Zhenglan Cable Technology Co., Ltd  

Shielded cable has the word "shielded" in it. As the name implies, it is a cable with the ability to resist external electromagnetic interference formed by adding a shielding layer to the transmission cable. The so-called "shielding" in the cable structure is also a measure to improve the distribution of the electric field. The cable conductor is made of multiple strands of wires twisted together. It is easy to form an air gap between it and the insulation layer. The surface of the conductor is not smooth, which will cause electric field concentration. 1. Cable shielding layer 1). Add a shielding layer of semi-conductive material on the surface of the conductor. It has the same potential as the shielded conductor and has good contact with the insulation layer, thereby avoiding local discharge between the conductor and the insulation layer. This layer of shielding is also called the inner shielding layer. There may also be gaps at the contact between the insulation surface and the sheath. When the cable is bent, the insulation surface of the oil-paper cable is prone to cracks. These are factors that cause local discharge. 2). Add a shielding layer of semi-conductive material on the surface of the insulation layer. It has good contact with the shielded insulation layer and has the same potential as the metal sheath, thereby avoiding local discharge between the insulation layer and the sheath. To make the conductive core and the insulating electric field uniform, medium and high voltage power cables of 6kV and above generally have conductor shielding layers and insulating shielding layers, and some low voltage cables do not have shielding layers. There are two types of shielding layers: semi-conductive shielding and metal shielding. 2. Shielded cable The shielding layer of this type of cable is mostly made of metal wires woven into a mesh or metal film, and there are many different ways of single shielding and multi-shielding. Single shielding refers to a single shielding net or shielding film, which can wrap one or more wires. Multi-shielding means multiple shielding nets and shielding films are in one cable. Some are used to isolate electromagnetic interference between wires, and some are double-layer shielding to enhance the shielding effect. The mechanism of shielding is to ground the shielding layer to isolate the induced interference voltage of the external connection to the wire. 1). Semi-conductive shielding The semi-conductive shielding layer is usually set on the outer surface of the conductive core and the outer surface of the insulating layer, respectively called the inner semi-conductive shielding layer and the outer semi-conductive shielding layer. The semi-conductive shielding layer is composed of a semi-conductive material with very low resistivity and thin thickness. The inner semi-conductive shielding layer is to even out the electric field on the outer surface of the core, and avoid partial discharge between the conductor and the insulation due to the uneven surface of the conductor and the air gap caused by the twisting of the core. The outer semi-conductive shielding layer is in good contact with the outer surface of the insulation layer, and is at the same potential as the metal sheath, avoiding partial discharge with the metal sheath due to defects such as cracks on the cable insulation surface. 2). Metal shielding For medium and low voltage power cables without metal sheaths, in addition to the semi-conductive shielding layer, a metal shielding layer must be added. The metal shielding layer is usually wrapped with copper tape or copper wire and mainly plays the role of shielding the electric field. Because the current passing through the power cable is relatively large, a magnetic field will be generated around the current. In order not to affect other components, the shielding layer can be added to shield this electromagnetic field in the cable. Moreover, the cable shielding layer can play a certain role in grounding protection. If the cable core is damaged, the leaked current can flow along the shielding layer like the grounding grid, playing a role in safety protection. It can be seen that the role of the cable shielding layer is still very large.

The selection of power cables should follow the following principles: 1. Rated voltage: Select appropriate wires and cables according to the voltage level of the place of use, and ensure that the rated voltage of the cable is not lower than the actual use voltage. 2. Current capacity: Select appropriate wire and cable cross-section according to the load current to ensure that the cable will not overheat under the maximum load, and the voltage drop is within an acceptable range. 3. Safety requirements: According to safety requirements, non-flammable cables, flame-retardant cables, halogen-free flame-retardant cables, fire-resistant cables, etc. can be selected. 4. Mechanical strength: When it is necessary to withstand mechanical tension, pressure and large-span creep resistance, reinforced cables such as copper wire or steel belt armored structural cables can be selected. 5. Economy: Under high load conditions, select according to economic current density, considering that power loss and capital investment should be within the most reasonable range. 6. Laying conditions: Select the model and specification of the cable according to the cable laying environment and laying method to ensure that the cable can adapt to specific laying conditions. 7. Environmental factors: Calculate the resistance and voltage drop of the cable considering the cable laying length and laying method, and select the flame retardant grade of the cable according to the safety requirements of the power system. 8. Comprehensive considerations: When selecting power cables, it is also necessary to comprehensively consider various factors such as purpose, voltage, environment, etc., and more accurately select the appropriate cable for a specific application through example calculations. Through the above principles, it can be ensured that the selection of power cables not only meets the actual use needs, but also has safety and economy.

In the production of wires and cables, the phenomenon of low insulation resistance is often encountered. There are many factors that affect the insulation resistance value of cables. In fact, there are four main factors that have a great influence on the insulation resistance coefficient. 1. The influence of temperature As the temperature increases, the insulation resistance coefficient decreases. This is due to the increase in thermal motion, the increase in ion generation and migration. Under the action of voltage, the conduction current formed by ion movement increases, and the insulation resistance decreases. Theory and practice show that the insulation resistance coefficient decreases exponentially with the increase in temperature, and the conductivity increases exponentially with the increase in temperature. 2. The influence of electric field strength When the electric field strength is in a relatively low range, the mobility of ions increases in a proportional relationship with the increase in electric field strength. Ionic current and electric field strength follow Ohm's law. When the electric field strength is relatively high, as the electric field strength increases, the mobility of ions gradually changes from a linear relationship to an exponential relationship. When the electric field strength is close to breakdown, a large amount of electron migration occurs, thereby greatly reducing the insulation resistance coefficient. The withstand voltage test voltage of various wire and cable products specified in the standard is in the stage where the ion mobility increases proportionally with the electric field strength, so the influence of the electric field strength on the insulation resistance coefficient cannot be reflected. When the sample is subjected to a breakdown test, the influence of the electric field on the insulation resistance coefficient is clearly reflected. 3. The influence of humidity Due to the high conductivity of water, the size of water molecules is much smaller than that of polymer molecules. Under the action of heat, the polymer macromolecules and the constituent chain segments move relatively, so that water molecules can easily penetrate into the polymer, increase the conductive ions in the polymer, and reduce the insulation resistance. The standard specifies immersion tests for various wires and cables. For example, before measuring the insulation resistance, the rubber specimen is immersed in water for 24 hours. The purpose is to meet the influence of moisture and water on electrical properties during use. Insulation resistance is one of the main electrical properties of insulating materials and an important indicator of wire and cable products or materials. Generally, the insulation resistance is required to be not less than a certain value. If the insulation resistance value is too low, the leakage current along the wire and cable line will inevitably increase, resulting in a waste of electrical energy. At the same time, the electrical energy will be converted into thermal energy, preparing for thermal breakdown and increasing the possibility of thermal breakdown. 4. Influence of material purity Impurities are mixed into the material, increasing the conductive particles in the material and reducing the insulation resistance. Therefore, the insulation resistance of a certain rubber and plastic material will reflect the purity of the material and verify whether it meets the standard. During the production of wires and cables, the process does not strictly follow the operating procedures, mixed impurities and materials bubble due to moisture, insulation core deviation or outer diameter size is smaller than the standard, insulation delamination or cracks, insulation scratches, etc. , will reduce the insulation resistance of the product. Therefore, in order to check the insulation resistance, it is necessary to check whether there are any problems in the process operation. During the use of wires and cables, measuring the changes in insulation resistance can also check the insulation damage and prevent accidents.

There are many types of wire and cable products, and their application range is very wide. If they are not stored properly, it will affect the life and safety of the cables, and even cause unnecessary disasters. Therefore, how to store them is an issue that needs attention. 1. When storing wires and cables, avoid water sources, and do not contact acids, alkalis and mineral oils. The outer skin of the wires is mostly plastic. Contact with corrosive liquids will cause the outer skin of the wires to swell, accelerate the damage of the outer skin and cause leakage, which is very dangerous. 2. Wires and cables cannot be exposed to the sun or in an ultra-high temperature environment for a long time, otherwise it will cause cracks or peeling on the outer sheath of the cable. 3. In the environment where wires and cables are stored, it is strictly forbidden to have gases that are harmful to cables, such as corrosive gases and flammable and explosive gases. 4. Wires and cables should be stored regularly, according to specifications and production time. The storage period is limited to the product's factory date, and generally should not exceed one and a half years. 5. Long-term storage of wires and cables will be affected by extrusion pressure, which may cause deformation of the sheath and cable. The cables should be rolled regularly. After rolling, the cables should be checked to see if they are intact to avoid damage that affects subsequent safe use. (Cable reels are not allowed to be laid flat) 6. The transportation of wires and cables is also the key to the storage and protection of wires. It is strictly forbidden to throw cable reels from high places during transportation, which may cause cracks in insulation and sheath, and damage the conductivity and mechanical properties of the cables.

Dear Customer Wecome your visiting our website. Here comes Chinese Traditional Dragon Boat Festival. Kindly note we will be on holiday from Sturday(June 8th) to Monday(June 10th). Work resume from Tuesday(June 11th). During holiday we will have limit access to email and work will stop temperately. Once work resume, we will get back to you at earliest time. Zhenglan Cable Technology Co., Ltd June 7th, 2024

In the wire and cable manufacturing industry, aluminum rods, aluminum alloy wires, aluminum alloy strips, profiles, etc. for electrical use are also important materials. One of the important testing items for conductive aluminum alloys is chemical composition analysis. In addition to determining the grade of aluminum alloys, another important purpose of composition analysis is to determine the content of impurity elements.   The reason why we need to analyze the impurity elements of conductive aluminum alloys is that the manufacturing process of aluminum alloys is to add a certain proportion of alloying elements to pure aluminum. These added alloying elements are usually trace elements, especially the percentage of trace elements added to conductive aluminum alloys. The mass fraction is generally not more than 1.0%. The trace alloying elements we commonly add are Cu, Mg, Fe, B, Zr and other elements, but Zr, Cr, V, Mn, Li and Ti have a serious impact on the resistivity of aluminum alloy conductor materials. Therefore, we must strictly control the content of Zr, Cr, V, Mn, Li 7 and Ti in aluminum alloy conductor materials. Reduce the harmful effects of impurity elements on the conductivity of aluminum alloys.

1. Cable type: Different cable types may require different connection methods. For example, low-voltage cables may require simple stripping and twisting, while high-voltage cables may require specialized connectors or soldering. 2. Current size: The size of the current will affect the selection of cables and also the selection of connection methods. For example, high currents may require stronger connections such as soldering or the use of specialized connectors. 3. Voltage level: Voltage level will also affect the choice of connection method. For example, high-voltage cables may require special connectors and insulation. 4. Environmental conditions: If the cable needs to work in harsh environments, such as high temperature, high humidity, chemical corrosion, etc., then it is necessary to select connection methods and materials that can adapt to this environment. 5. Convenience of installation and maintenance: Although some connection methods are simple to install at the beginning, they are difficult to maintain later, while some connection methods are complicated to install at the beginning but easy to maintain later. 6. Economic factors: The price differences of different types of connection methods and materials may also affect the final choice.

Dear Friend Thanks for visiting our website. Shall we have anything you need, please feel free to send us your inquiry.   We are now having a 5-day Labour Day holiday from May 1st till 5th. Work resume from May 6th(Monday). During holiday, work will be slower than before but once we resume work we will handle at first time.   Hope you will have a happy holiday also.   Zhenglan Cable Technology Co., Ltd April 30th, 2024   --------------   Estimado amigo Gracias por visitar nuestro sitio web. Si tenemos algo que necesite, no dude en enviarnos su consulta.   Ahora tendremos un feriado de 5 días por el Día del Trabajo, del 1 al 5 de mayo. Reanudación laboral a partir del 6 de mayo (lunes). Durante las vacaciones, el trabajo será más lento que antes, pero una vez que reanudemos el trabajo, lo haremos por primera vez.   Espero que usted también tenga unas felices vacaciones.   Tecnología de cable Co., Ltd de Zhenglan 30 de abril de 2024

Dear friends, Greetings from Zhenglan Cable Technology Co., Ltd! Our company will participate in the Middle East Energy Dubai exhibition held on 16 - 18 April 2024. We would be honored if you could visit us at our booth during the day. Booth Number: H1.B22 Exhibition Place: Dubai World Trade Centre, UAE We will look forward to meeting you there! Best Regards, Zhenglan Cable Team

Twin and earth (often written "T&E" and sometimes "T and E") cable is a type of 300/500V flat sheathed electricity cable, containing two insulated current-carrying conductors and and a Circuit Protective Conductor (CPC = PE = Earth). In Australia and New Zealand this type of cable is referred to as 'Flat TPS' (Thermo-plastic sheathed), as well as "Twin and Earth" or "Twin with Earth". It is commonly used for fixed wiring in domestic and commercial premises. It is not intended to be used where it is subject to regular movement or sunlight, because the sheathing is affected by ultraviolet radiation.. It is suitable for laying in conduit or trunking where mechanical protection is required. Twin and Earth cable is a general fixed wiring and lighting cable, containing three conductors.   Minimum bending radius: Diameter up to 10mm - 3 x overall diameter Diameter 10mm to 25mm - 4 x overall diameter (Based upon the larger dimensions)   The disadvantages of twin and earth cable? It is not suitable for overhead catenary use. Twin and Earth cable is normally made with PVC sheathing and insulation, which has an almost indefinite life in the right conditions. However UV light will cause it to fail, so Twin and Earth is not suitable for use outdoors.It can also be made with low smoke zero halogen (LSZH) outer sheathing   Zhenglan Cable Technology Co., Ltd is professional manufacturer of various building wire, electrical cable, twin earth cable. Please feel free to send us your needs for a quote.

New energy vehicles New energy vehicle cables can be divided into in-car cables, charging pile cables and on-board charging cables according to different application scenarios. The rapid development of new energy electric vehicles has provided good market opportunities for its supporting cable industry. As vehicle manufacturers increase their investment in the field of new energy vehicles, vehicle electrification has become a general trend, and new energy vehicle cables will also usher in new growth points. It is expected that the size of my country's automotive cable market will reach 18.06 billion yuan in 2025. Whether from the perspective of industrial transformation or energy strategy, the prospects of new energy automobile cables are very broad. In the next five years, the field of new energy automobile cables will usher in huge development space. Marine construction China's submarine cable industry has shown a fluctuating upward trend in recent years. In 2020, driven by the "rush to install" offshore wind power, the size of the submarine cable market increased significantly by 12.64% year-on-year, reaching approximately 13.4 billion yuan, reaching its peak in recent years. Based on the future demand for offshore wind power, international communication network upgrades, and offshore oil platform development in multiple application fields, China's submarine cable market is expected to reach 20 billion yuan in 2027, with a compound annual growth rate of approximately 6%. Special equipment At present, industries such as shipbuilding, rail transportation, clean energy, aerospace, petrochemicals, and new energy vehicles all require the use of a large number of special cables. With the advancement of science and technology, the transformation and upgrading of traditional industries, and the vigorous development of strategic emerging industries and high-end manufacturing, my country's economy and society are further developing towards safety, environmental protection, low-carbon energy conservation, informatization, and intelligence. The construction and modernization of national smart grids Urban construction, large-scale transformation of urban and rural power grids, and new energy power station construction have put forward higher requirements for the application of wires and cables, which also provide new development opportunities for the development of special wires and cables.

The wire and cable market is a key infrastructure market. With economic development and technological advancement, the demand for wire and cable continues to increase. In the next few years, including 2024, some cable markets will develop significantly, and some cable products will usher in broad market demand. Some people believe that markets are currently relatively stable and will continue to improve in the future, such as the following markets: Power grid construction my country's power grid construction is still in the development stage. The higher the voltage level, the more conducive to long-distance power transmission. In the future, large-scale cross-regional power grid construction in China will require long-distance power transmission. Currently, judging from the construction planning of high-voltage and ultra-high-voltage lines, supporting cables The demand is on the rise. According to the State Grid's plan, investment will increase to 520 billion yuan in 2023, a year-on-year increase of 4%. Power grid investment and new infrastructure are the driving force for the development of the cable market. Photovoltaic/energy storage/hydrogen energy market The energy sector is an important area of the wire and cable market. With the continuous development of my country's photovoltaic industry, my country's photovoltaic cable industry will still be in a stage of rapid development. It is expected that the size of my country's photovoltaic cable market will reach 18.56 billion yuan in 2023. In recent years, in order to implement the country's strategic deployment of "dual carbon" goals and promote the green and low-carbon transformation of energy, the Chinese government has introduced a series of policies and measures. In the next few years, new energy industries such as photovoltaics, wind power, and energy storage will maintain rapid growth, and the rapid development of their industries will promote the development of photovoltaic cable companies.  

Dear Customer Thanks for visiting our website.   Kindly note we will be on Chinese Traditional Spring Festival which is from February 7th(Wednesday) till 17th(Saturday). Work resume time is on February 18th(Sunday). Happy New Year!!!   During holiday, sorry to say that work will become slow and even stop. We will get back to you immediately after holiday. Thank you for your kind understanding.   Best Regards Zhengla Cable Technology Co., Ltd 2024.2.5

Aluminum alloy cables and aluminum core cables are two common power transmission line materials. Their conductor materials are different, so their prices are also different. Generally speaking, the price of aluminum alloy cables is relatively high. The following are some factors that affect the price: 1. Conductor material: The conductor of aluminum alloy cable is made of aluminum alloy, while the aluminum core cable is made of ordinary aluminum. The manufacturing cost of aluminum alloy is relatively high, which makes aluminum alloy cables relatively expensive. 2. Performance differences: Aluminum alloy cables usually have better electrical conductivity and mechanical properties and can meet some special requirements, which is one of the reasons for their higher price. 3. Manufacturing process: The production and manufacturing process of aluminum alloy cables is relatively complex and requires a higher level of technology and equipment, which will also affect its price.

Dear users,   Thank you for your continued support and trust! On this special Christmas season, we would like to extend our warmest wishes and greetings to you.   Christmas is a time filled with love and joy, and we hope you enjoy a cozy and joyful holiday season with your family, loved ones, and friends. May you feel an abundance of warmth and happiness during this festive time and have a wonderful New Year ahead.   As a token of appreciation for your ongoing support, we will continue to strive to provide you with high-quality services and products that cater to your needs. In the coming year, we will keep innovating and improving to bring you more surprises and convenience.   Wishing you and your family an unforgettable Christmas and a prosperous New Year! May the new year bring you endless happiness, health, and success!   Once again, thank you for your support, and Merry Christmas!   Warmest regards Zhenglan Cable    

23. Where are the inner shielding layer and outer shielding layer of power cables located? What materials are used? What does it do? Answer: In order to have better contact between the insulation layer and the cable conductor and eliminate the increase in electric field intensity on the conductor surface caused by the roughness of the conductor surface, the conductor surface is generally covered with an inner shielding layer of metallized paper or semiconductor paper tape. In order to ensure better contact between the insulation layer and the metal sheath, an outer shielding layer is generally wrapped around the insulation layer. The outer screen layer is made of the same material as the inner screen layer, and sometimes it is also bound with copper tape or braided copper wire tape.   24. What should we pay attention to during the transportation, loading and unloading of cables? Answer: (1) During transportation, loading and unloading, cables and cable drums should not be damaged. It is strictly forbidden to push cable drums directly off the vehicle. Cables should generally not be transported or stored flat. (2) Before transporting or rolling the cable drum, it must be ensured that the cable drum is firm and the cable is wound tightly. The oil pipe between the oil-filled cable and the pressure oil tank should be fixed and not damaged. The pressure oil tank should be secure and the pressure indication should meet the requirements. 25. What aspects should be considered when selecting the cross-section of power cables? Answer: The following aspects should be considered: (1) The long-term operating current allowed by the cable; (2) Thermal stability in the event of short circuit; (3) The voltage drop on the line cannot exceed the allowable working range. 26. What are the advantages of power cables compared with overhead lines? Answer: (1) Reliable operation. Because it is installed in hidden places such as underground, it is less damaged by external forces and has fewer chances of failure. The power supply is safe and will not cause harm to people; (2) The maintenance workload is small and frequent inspections are not required; (3) No need to erect poles and towers; (4) Helps improve power factor.   27. What measures are taken to prevent cable fire? Answer: (1) Use flame-retardant cables; (2) Use fireproof cable brackets; (3) Use fire retardant coatings; (4) Fire partition walls and fire baffles should be installed at cable tunnels, mezzanine exits, etc.; (5) Overhead cables should avoid oil pipelines and explosion-proof doors. Otherwise, local pipe penetration or heat insulation and fire prevention measures should be taken.   28. What is a cable failure? How many common types are there? Answer: Cable failure refers to the failure of insulation breakdown of the cable during preventive testing or the failure of the cable line to cause a power outage due to insulation breakdown, wire burnout, etc. during operation. Common faults include ground faults, short circuit faults, disconnection faults, flashover faults and mixed faults.   29. According to the "Regulations on Safety in Electrical Industry", what are the conditions that electrical workers must meet? Answer: The following conditions must be met: (1) Healthy as determined by a doctor, with no illness that would hinder work; (2) Have necessary electrical knowledge, master relevant procedures, professional techniques and safe operation techniques according to their duties and nature of work, and pass the examination; (3) Be proficient in first aid methods for electric shock.   30. Where are the inner shielding layer and outer shielding layer of power cables located? What materials are used? What does it do? Answer: In order to have better contact between the insulation layer and the cable conductor and eliminate the increase in electric field intensity on the conductor surface caused by the roughness of the conductor surface, the conductor surface is generally covered with an inner shielding layer of metallized paper or semiconductor paper tape. In order to ensure better contact between the insulation layer and the metal sheath, an outer shielding layer is generally wrapped around the insulation layer. The outer screen layer is made of the same material as the inner screen layer, and sometimes it is also bound with copper tape or braided copper wire tape.

Medium voltage power cables mostly use cross-linked polyethylene insulation. Ordinary cross-linked polyethylene insulation cables are damaged by mechanical stress or external forces during installation and operation, or the cables are operated for a long time in a humid and watery environment, which can cause external moisture to penetrate into the interior of the cables. The chance of forming water trees under the action of the electric field is greatly increased, and water trees are transformed into permanent electrical trees under the action of the electric field, Causing insulation breakdown in a relatively short period of time. Once the outer protective layer of the cable is damaged, water ingress into the cable can cause corrosion of the steel strip and copper strip, decrease the insulation performance, and greatly shorten the service life of the cable. Therefore, the industry recommends using water resistant cross-linked polyethylene cables.

The function of insulation screen in MV cable:  The insulation and shielding structure of medium voltage cables is relatively complex, usually composed of multiple components such as cable core, insulation layer, semiconductor shielding layer, metal sheath, and outer protective layer. 1. Protect the cable core The insulation shielding of medium voltage cables can effectively protect the cable core from mechanical damage and external electromagnetic interference. 2. Enhance cable durability The semiconductor shielding layer of medium voltage cable insulation can not only balance the electric field and prevent partial discharge, but also enhance the durability of the cable and extend its service life. 3. Improve cable transmission performance The insulation and shielding of medium voltage cables can effectively reduce the transmission loss and crosstalk interference of cables, and improve the transmission performance and stability of cables. 4. Safety The insulation and shielding of medium voltage cables can effectively prevent accidents such as fires and electric shocks, ensuring the safety of the power system and personnel.

18. What are the requirements for the mechanical strength of cable conductor connection points?   Answer: The mechanical strength of the connection point is generally lower than the tensile strength of the cable conductor itself. For fixedly laid power cables, the tensile strength of the connection point is required to be no less than 60% of the tensile strength of the conductor itself. 19. What are the main properties of the insulation layer material of power cables?   Answer: It should have the following main properties: (1) High breakdown strength; (2) Low dielectric loss; (3) Quite high insulation resistance; (4) Excellent discharge resistance; (5) Has certain softness and mechanical strength; (6) The insulation performance is long-term and stable. 20. The applications of wires and cables are mainly divided into three categories:   (1), power system The wire and cable products used in the power system mainly include overhead bare wires, busbars (busbars), power cables (plastic cables, oil-paper power cables (basically replaced by plastic power cables), rubber sheathed cables, overhead insulated cables), branch cables (replacing some busbars), electromagnetic wires, and electrical equipment wires and cables for power equipment, etc.   (2), Information transmission system The wires and cables used in information transmission systems mainly include local telephone cables, television cables, electronic cables, radio frequency cables, optical fiber cables, data cables, electromagnetic wires, power communication or other composite cables, etc.   (3), mechanical equipment, instrumentation systems In addition to overhead bare wires, almost all other products in this section are applied, but mainly power cables, electromagnetic wires, data cables, instrumentation cables, etc.   21. Wire and cable products are mainly divided into five categories:   (1), Bare wires and bare conductor products The main characteristics of this type of product are: pure conductor metal, without insulation and sheath layers, such as steel core aluminum stranded wire, copper aluminum busbar, electric locomotive wire, etc.; the processing technology is mainly pressure processing, such as smelting, rolling, drawing system, stranding/compression stranding, etc.; the products are mainly used in suburban areas, rural areas, user main lines, switch cabinets, etc.   (2), power cable The main features of this type of product are: extruding (winding) the insulation layer on the conductor, such as overhead insulated cables, or twisting several cores (corresponding to the phase line, neutral line and ground wire of the power system), such as overhead insulated cables with more than two cores , or add a sheath layer, such as plastic/rubber sheathed wire and cable. The main process technologies include drawing, stranding, insulation extrusion (wrapping), cabling, armoring, sheath extrusion, etc. There are certain differences in the different process combinations of various products. The products are mainly used in the transmission of strong electric energy in generation, distribution, transmission, transformation and power supply lines, with large currents (tens of tens of amps to thousands of amps) and high voltages (220V to 500kV and above).   (3) Wires and cables for electrical equipment The main features of this type of products are: a wide range of varieties and specifications, a wide range of applications, most of the operating voltages are 1kV and below, and new products are constantly derived for special occasions, such as fire-resistant cables, flame-retardant cables, low-smoke halogen-free/low-smoke Smoke-resistant low-halogen cables, termite-proof, mouse-proof cables, oil-resistant/cold-resistant/temperature-resistant/wear-resistant cables, medical/agricultural/mining cables, thin-walled wires, etc.   (4), communication cables and optical fibers (brief introduction) With the rapid development of the communications industry in the past two decades, products have also developed at an alarming rate. From the simple telephone and telegraph cables in the past, it has developed into thousands of pairs of voice cables, coaxial cables, optical cables, data cables, and even combined communication cables. The structural dimensions of such products are usually small and uniform, and require high manufacturing precision.   (5), electromagnetic wire (winding wire) Mainly used in various motors, instruments, etc. Derivatives/new products of wires and cables are mainly due to different application situations, application requirements, convenience of equipment, and reduction of equipment costs. They use new materials, special materials, or change the product structure, or improve process requirements, or will be different. A variety of products are produced by combining them. Use different materials such as flame-retardant cables, low-smoke halogen-free/low-smoke low-halogen cables, termite-proof, mouse-proof cables, oil-resistant/cold-resistant/temperature-resistant cables, etc.; change the product structure such as: fire-resistant cables, etc.; improve technology Requirements such as: medical cables, etc.; combined products such as: OPGW, etc.; convenient installation and reduced equipment costs, such as: prefabricated branch cables, etc.   22. What requirements should be met when laying cables? Answer: The following requirements should be met: (1) In terms of safe operation, try to avoid all kinds of external damage and improve the power supply reliability of cable lines; (2) Economically, consider the aspect of saving the most investment; (3) In terms of construction, the path of the cable line must be convenient for work and maintenance after operation.

11. What should be stated on the cable sign? What are the requirements for writing? Answer: The cable line design number, cable model, specification and starting point should be indicated on the signboard. Cables used in parallel should have sequence numbers. The handwriting is required to be clear and not easy to fall off.   12. How should the yellow wax silk ribbon, black glass paint ribbon, alkali-free glass ribbon, etc. used for making cable joints be dehumidified before construction? Answer: ① Constant temperature drying method: roll the insulating tape into a small roll with a diameter of 25~30mm, put it into a constant temperature drying oven at 110~120℃ for 4~5 hours, cool and dry, take it out, and put it into a dry sealed cylinder. ②Oil immersion moisture drainage method: Put the small roll of insulation tape into the cable oil with a constant temperature of 120~130℃, keep a distance of 30mm from the bottom of the pot. After a certain period of time, the oil surface will no longer produce foam, take it out, and put it into the stored cable. In oil barrels, the oil level should exceed all contained objects and be sealed. 13. What is the function of the cable outer sheath? Answer: Protect the inner protective layer from mechanical damage and chemical corrosion and enhance mechanical strength. 14. What requirements should outdoor cable trenches meet? Answer: The upper part of the cable trench should be slightly higher than the ground and covered with a concrete cover. The cables should be laid flat on the bracket and have good drainage pipes.   15. What is the function of the inner sheath of the cable? Answer: Keep the insulation layer from coming into contact with water, air or other objects, prevent the insulation from getting damp and prevent the insulation layer from mechanical damage.   16. What should you pay attention to when using wire cutters? Answer: Before use, be sure to check whether the insulation of the insulated handle is intact. Do not use wire cutters to cut metal wires exceeding the specifications allowed. It is also prohibited to use wire cutters instead of hammers to hit the tool to avoid damage.   17. What is insulation strength? Answer: When an insulating material is in an electric field, it will be broken down when the electric field intensity increases to a certain limit. This electric field intensity that leads to insulation breakdown is called insulation strength.

Armored cables are made of conductors of different materials installed in metal casings with insulating materials, and are processed into a flexible and solid assembly. The mechanical protective layer of armored cables can increase the mechanical strength of the cable and improve its corrosion resistance. It is a cable designed for areas prone to mechanical damage and erosion. It can be laid in any way, and is more suitable for direct burial in rocky areas. Armored cables are also divided into steel tape armored cables and steel wire armored cables.   1. Purpose: Steel tape armor is only used for the laying of directly buried cables or ordinary pipes, ordinary ground, tunnels, etc. The thin steel wire armor can withstand general longitudinal tension, so it is suitable for short-distance overhead laying or vertical and vertical laying. Abroad, there are more steel wire armored cables!   2. Price: The corresponding steel wire armor is more expensive. Because steel wire armor is difficult to produce and the cost is high.   3. Current-carrying capacity: There is not much difference, but they must use countermagnetic steel strips or steel wires.   4. Depending on the use environment, choose different forms of armored cables: steel tape armor can withstand mechanical pressure, and steel wire armor can withstand mechanical tension.   Zhenglan Cable can do both types of armored cable. Welcome your inquiry.

Dear Customer,   Thanks for your visiting our website.   Please be informed that our company will remain closed from September 29th to October 6th due to the National Day holidays Normal business will resume on October 7th. We apologize for any inconvenience caused by our temporary closure and appreciate your understanding.   Zhenglan Cable Technology Co., Ltd 2023.9.28

6. What regulations should be followed when selecting the cross-section of power cables? Answer: The selection of power cables should follow the following principles: (1) The rated voltage of the cable must be greater than or equal to the rated voltage of the power supply system at the installation point; (2) The continuous allowable current of the cable should be equal to or greater than the maximum continuous current of the power supply load; (3) The wire core cross-section must meet the stability requirements of the power supply system during short circuit; (4) Check whether the voltage drop meets the requirements based on the cable length; (5) The minimum short-circuit current at the end of the line should enable the protective device to operate reliably.   7. What are the advantages of cross-linked polyethylene cables and oil-paper cables? Answer: (1) Easy to install because it allows a small minimum bending radius and is lightweight; (2) Not affected by line differences; (3) Good thermal performance, allowing high operating temperature and large transmission capacity; (4) The cable accessories are simple and all are dry structures; (5) Operation and maintenance are simple and there is no oil leakage problem; (6) The price is lower; (7) High reliability and low failure rate; (8) Few manufacturing steps, simple process, and significant economic benefits.   8. What are the requirements for clamps for fixing AC single-core cables? Why? Answer: The clamp should have no iron parts to form a closed magnetic circuit. This is because when the cable core passes current, magnetic lines of force are generated around it. The magnetic lines of force are proportional to the current passing through the core. If magnetically conductive materials such as iron parts are used, according to It can be seen from electromagnetic induction that eddy currents will be generated in the iron parts to cause the cable to heat up and even burn the cable. Therefore, iron parts cannot be used as fixed fixtures for single-core AC cables.   9. What are the biggest features and advantages of heat shrinkable cable head accessories? Answer: The biggest feature of heat shrink accessories is that they use stress tubes instead of traditional stress cones. It not only simplifies the construction process, but also reduces the size of the joint terminals. It is easy to install, saves time and labor, has superior performance, and saves metal. Heat-shrinkable cable accessories are both potted and dry-packed, combining the advantages of both types of accessories.   10. What inspections should be carried out before laying cables? Answer: (1) The brackets should be complete and the paint should be complete. (2) The cable model, voltage, and specifications comply with the design. (3) The cable insulation is good. When there is doubt about the sealing of oil-paper cables, moisture judgment should be made; directly buried cables and small bottom cables should pass the DC withstand voltage test; oil samples of oil-filled cables should pass the test. (4) The oil pressure of oil-filled cables should not be lower than 1.47MPa.

1. What are the types of commonly used wires and cables according to their uses? Answer: According to the purpose, it can be divided into bare wires, insulated wires, heat-resistant wires, shielded wires, power cables, control cables, communication cables, radio frequency cables, etc. 2. What kinds of insulated wires are there? Answer: Common insulated wires are as follows: PVC insulated wire, PVC insulated flexible wire, nitrile polyvinyl chloride mixture insulated flexible wire, rubber insulated wire, agricultural underground direct buried aluminum core plastic insulated wire, rubber insulated cotton yarn Textile flexible wires, PVC insulated nylon sheathed wires, PVC insulated flexible wires for electricity and lighting, etc.   3. What are the cable accessories? Answer: Commonly used electrical accessories include cable terminal junction boxes, cable intermediate junction boxes, connecting pipes and terminals, steel plate junction slots, cable trays, etc.   4. What is the cable intermediate joint? Answer: The device that connects the conductor, insulation shielding layer and protective layer of the cable to the cable to connect the cable line is called the cable intermediate joint.   5. What aspects should be considered when selecting the cross section of the power cable? Answer: The following aspects should be considered: (1) The working current that the cable is allowed to pass through for a long time; (2) thermal stability in case of short circuit; (3) The voltage drop on the line cannot exceed the allowable working range.

Concentric Conductor Shielded Neutral Power Cable has advantages as below: 1. When the power is transmitted, it will not interfere with the surrounding electrical equipment; it also eliminates the impact of external electromagnetic interference on the electrical equipment connected to the cable. 2 It can avoid breakdown or damage caused by strong lightning electromagnetic effect voltage, and improve the lightning protection effect and reliability of high-rise buildings. 3. It can improve the sensitivity of the overcurrent protection device at the hand end of the line, so that the cable and the electrical equipment connected to it can be effectively protected. 4. It has low and uniform positive (reverse) sequence and zero sequence impedance, which is beneficial to improve the quality of copper electricity. 5. The grounding fault caused by one-phase insulation breakdown can be eliminated as soon as possible.

The International Energy Agency recently stated that by 2027, solar power generation is expected to surpass coal-fired power generation and become the main way of generating electricity. So, why is solar power likely to become the main force of new energy in the future? More than a decade ago, solar energy was insignificant in the global energy race, accounting for the smallest share of all major sources of electricity, less than 1%. But things have changed now, with the International Energy Agency (IEA) saying that within three years, solar will generate more electricity than natural gas. Within four years, by 2027, it could overtake coal as the dominant form of electricity generation. Solar electricity installation costs have dropped dramatically in recent years An important reason is that the installation cost of solar power has dropped significantly. Data show that for utility-scale solar energy, the average cost of construction and operation has continued to decline since 2009, and will only be about $36 per megawatt-hour by 2021, a drop of about 90% compared to 2009. The cost of coal has changed little, at about $108 per megawatt-hour in 2021. Bahar, an analyst for the International Energy Agency's renewable energy market, said that solar power is expected to account for almost 60% of new power installations in the next five years. Governments are increasingly paying attention to the development of renewable energy In addition, in recent years, governments of various countries have paid more and more attention to energy security, and have also introduced corresponding policies to support it. According to the EU plan, by 2025, its installed capacity of solar photovoltaic power generation will more than double that of 2020, reaching 320 GW, and by 2030 it will reach 600 GW. The U.S. Inflation Reduction Act is expected to allow solar developers to enjoy certain tax credits within 10 years to carry out long-term and large-scale construction.   Home solar power market has broad prospects Another point that cannot be ignored is that the construction scale of solar energy can be large or small. In addition to huge arrays, it can also be a single battery panel on the roof. Therefore, household solar power generation is also an important market. The CEO of a solar energy company in the United States mentioned in an interview with CNBC that the surge in demand for electric vehicles today may also drive the demand for household solar power generation in the future because it is convenient, cheap and reliable.  

Cable manufacturers are constantly challenged with wider temperature ranges, more shielding functions and higher mechanical durability, as well as characteristics such as bending resistance and chemical resistance required for extremely harsh environments and increasingly complex applications. However, cable failures and system downtime still occur from time to time, why?   Cable Faults Many problems caused by cable faults, especially those operating in extreme and harsh environments, can be avoided if the cables are selected correctly from the outset. People might say that choosing a cable is easy, but is that really the case? Indeed, matching the correct temperature range and relying on a PVC jacket for protection is simple. However, there are far more issues to consider.   Engineers have many details to consider before finalizing a perfectly matched cable. Flex and flex cables require specific flex shields. When the shield is torn and continuity is lost, the choice of standard foil shielding can lead to system failure. The distinction between flexibility and bendability should be kept in mind. It is important that the cables be able to be bent and fitted, the flexible cables are easier to install and also simplifies fault detection in cabinets and cable trays.   When the cable is used to connect to the cabinet, the round cable provides a better seal than the typical spiral cable. Therefore, it is necessary to correctly select the degree of bending after considering the line. In some manufacturing applications, cables will be constantly being bent. Ability to withstand millions of bends is more complicated than flexibility. So, how to choose a curved cable? The first thing to consider is the type of bending, is it uniaxial, twisted, or multi-axial? Each type requires different characteristics of the cable.

Dear Sir/Madame, Email received. Kindly note that we are now spending a 3-day Dragon Boat holiday from June 22nd(Thirsday) to June 24th(Saturday). During holiday we have limit access to email, we're sorry for not being able to reply you or give you quotation timely. Once we come back, we will contact you at our first time. Thanks for your kind understanding. ---------------------------------- Estimado Señor / Señora, Correo electrónico recibido. Tenga en cuenta que ahora estamos pasando unas vacaciones de 3 días en Dragon Boat del 22 de junio (jueves) al 24 de junio (sábado). Durante las vacaciones, tenemos acceso limitado al correo electrónico, lamentamos no poder responderle o darle una cotización a tiempo. Una vez que volvamos, nos pondremos en contacto con usted en nuestra primera vez. Gracias por su comprensión. Zhenglan Cable Technology Co., Ltd 2023/6/21  

1. Contact: The backbone cable refers to the cable directly connected to the power supply; the branch cable refers to the cable that comes out of the distribution box and connects to the user or each workshop; the distribution cable refers to the cable that is electrically connected to the distribution box. Their function is to act as a bridge chain connecting the telecommunications room to each user client.   2. Difference: The number of backbone cables and distribution cables cannot be similar. The backbone cable should be one or two, the branch cable needs more than two, and the distribution cable should be more. Branch cables are divided into vertical branches and Horizontal branch. For vertical branches, they are mainly applicable to high-rise buildings. Generally, they are measured on site and divided according to the drawing, that is, the cross sectional area of cables is selected according to the load of each floor, the cable model is selected according to the fire resistance rating of the project, and the cable length is selected according to the distance between the low-voltage distribution cabinet and the highest floor of the branch; For Horizontal branch cable, the line selection basis is the same as that for vertical branch, but the length of Horizontal branch cable can be larger than the trunk line, but its sectional area should be smaller than the trunk line section. It should be noted that the vertical main line should be higher than the three section levels of the branch line.

The choice of cable sheath should be made in accordance with the requirements of relevant standards in combination with different situations. 1 The selection of cable sheath should meet the following requirements: 1.1 For single-core power cables in AC systems, when it is necessary to enhance the cable’s resistance to external forces, non-magnetic metal armor layers should be used, and steel armor without effective non-magnetic treatment should not be used. 1.2 For cables in humid, chemically corrosive environments or susceptible to water immersion, the metal layer, reinforcement layer, and armor should have polyethylene outer sheaths, and the thick steel wire armor of cables in water should have extruded outer sheaths.   2. The selection of the outer sheath of the cable during direct burial laying shall meet the following requirements: 2.1 When the cable is subjected to high pressure or has the risk of mechanical damage, it should have a reinforcement layer or steel tape armor. 2.2 In the soil where displacement may occur, such as quicksand layer and backfill land zone, the cable should be armored with steel wire. 2.3 For extruded cables used in areas seriously endangered by termites, outer sheaths with higher hardness should be selected, or thin outer sheaths with higher hardness can be extruded on ordinary outer sheaths. The material can be nylon or special polyolefin copolymerized Objects, etc., can also be armored with metal sleeves or steel tapes.   3. The selection of cable sheath for fixed laying in the air shall meet the following requirements: 3.1 When the small cross-section extruded plastic insulated cables are directly laid on the arm support, they should be armored with steel tape. 3.2 In places with high safety requirements and serious rodent infestation, such as underground passenger transportation and commercial facilities, plastic insulated cables should be armored with metal tape or steel tape. 3.3 When the cables are under high-drop force conditions, the multi-core cables shall be armored with steel wires, and the AC single-core cables shall comply with the provisions of Item 1   4 The selection of cable sheath for underwater laying shall meet the following requirements: 4.1 Steel tape armoring can be used for cables that do not require armored layers to bear tension in ditches, unnavigable creeks, etc. 4.2 For cables in rivers, lakes and seas, the type of steel wire armor selected should meet the stress conditions. When the laying conditions have protection requirements such as mechanical damage, the outer sheath that meets the protection and corrosion resistance enhancement requirements can be selected.

Characteristics of rubber sheathed cables: 1. incomparable softness of other wires and cables; 2. Good electrical insulation performance and chemical stability; 3. Good physical and mechanical properties and wear resistance; 4. Requirements for oil resistance, flame retardancy, cold resistance, and heat resistance. Choosing a cable that suits you has become a key issue. 1： Have a detailed understanding of the performance indicators of cables in various aspects, such as the wear resistance, compression resistance, and service life of rubber sheathed cables. Conduct a detailed inquiry and understanding, and then determine whether it meets your own usage conditions 2： The influence of the surrounding environment on the usage of cables. During the use of cables, in addition to being limited by their own usage conditions, there are also some external factors that play a decisive role. For example, if there is interference from magnetic fields, the cables need to be shielded; If it is a welding robot, due to the long working time and high temperature, it poses a great challenge to the outer sheath of the cable. Therefore, the selection should be based on the actual situation. 3： Clarify the use function of cables, whether it is control cables or rubber sheathed cables, no matter how excellent their performance is. What we need to do is to install the cables in positions suitable for their use. Only in this way can we achieve the original performance and service life of the cables.

Dear Customer, Thanks for visiting our website. Kindly note we will be on a 5-day May Day holiday from Saturday (April 29th, 2023) to Wednesday(May 3rd.2023). During holiday, work will become slow or even stopped temperately and we will have limit access to email. Kindly ask for your understanding. Once work resume, we will get back to you at first time. Regards Zhenglan Cable Technology Co., Ltd 2023.04.28

Among our commonly used power cables, rubber sheathed cables are also one of them. Rubber sheathed cable is a kind of soft and movable cable with multi-strand thin copper wire as conductor, rubber insulation and rubber sheath. Generally speaking, it includes general-purpose rubber-sheathed flexible cables, electric welding machine cables, submersible motor cables, radio device cables, and photographic light source cables. So what are the uses of rubber sheathed cables and what are the selection principles? Here is a brief introduction.   Application of Rubber-sheathed Cables Rubber-sheathed cables are widely used in various electrical equipment, such as household appliances, electric machinery, electrical equipment and portable power cords for appliances, and can be used indoors or outdoors. According to the external mechanical force of the cable, the product structure is divided into three types: light, medium and heavy, and there are appropriate connections in the section. Generally, light-duty rubber-sheathed cables are used in household appliances and small electric equipment, requiring softness, lightness, and good bending performance; medium-duty rubber-sheathed cables are widely used in agricultural electrification except for industrial use, and heavy-duty cables are used in such as port machinery, searchlights, Large-scale hydraulic irrigation and drainage stations for family business and other occasions. This type of product has good versatility, complete series of specifications, good and stable performance.  

MDPE has very high resistance to abrasion and it is extremely hard and has a low dielectric constant with superior oxidation resistance. The hardness of the MDPE cable sheathing protects the cable from sharp objects dropped or loaded onto the cable. This helps MDPE finds particular usage in transmission cables in the toughest of environments, notably those with the high ambient temperatures found in tropical and subtropical countries. But at these high ambient temperatures alternative sheathing materials such as PVC would be soft and prone to damage easily during laying of the cables.   Compared with LDPE (low density polyethylene), MDPE has significantly more strength enabling it to be pulled under heavy load for cabling applications; while compared to HDPE (high density polyethylene), HDPE has improved resistance to cracking.   Besides, various additives can be applied to MDPE compounds to improve fire retardant properties, UV and weathering resistance and the chemical degradation.

First of all, look at the color. The copper core is yellowish and reddish, indicating that the quality of the copper used is better, while the yellowish white is the reaction of low-quality copper. For aluminum core wires, regular ones must be shiny, shining silver-white light under the light, while those that are dark and look dark are of poor quality.   Secondly, bend the wire by hand to test its toughness. A good wire has good toughness and can be bent very well. Some unqualified wires are bent a few times and their insulation layer is broken, and some can even be peeled off by hand. Insulation. Then, it must be checked whether the length and the thickness of the wire core have been tampered with. According to the relevant standards, the error of the length of the wire cannot exceed 5%, and the diameter of the cross-section cannot exceed 0.02%. Short of two catties, the phenomenon of falsification on the cross-section.   Also intercept a section of insulation to see if its core is in the middle of the insulation. What is not centered is the phenomenon of core eccentricity caused by low craftsmanship. When using it, if the power is low, it will be safe. Once the amount is large, the thinner side is likely to be broken down.   Finally, we can also check whether the identification is complete. There should be the name of the cable factory, wire model, specification, cross-sectional area, length, rated voltage, date of manufacture, and the implemented certification number or certification mark. If these signs are incomplete or absent, consumers should be cautious when purchasing. .

UNE 20460-3:1996 standard regulations about the cable usage under dverse environmental conditions, especially to what extent an electrical cable can be exposed to moisture. AD1 grade: The cable can be used in which the walls do not generally show traces of water, but can appear in small periods, for example, in the form of steam and which dries quickly thanks to good ventilation. AD2 grade: cables can be used under situlations in which the water vapour occasionally condenses in the form of water drops or when vapour may occasionally be present. AD3 grade: Water droplets fall at an angle of more than 60º to the vertical, location in which water vapour appears as a continuous film on the walls and/or floors. AD4 grade: Water jets in all directions, locating where the cable may be subject to water projections, for example, application to certain luminaires or cabinets installed outdoors. AD5 grade: Water jets in any direction AD5, locating at where hoses are regularly used in the presence of water (patios, car washes). AD6 grade: used in locations at the edge of the sea, such as beaches, docks, etc. There are possibility of water waves. AD7 grade: Used in locations susceptible to flooding and/or where the water can reach a maximum of 150 mm above the highest point of the equipment, the lowest part of the equipment can be more than one metre below the surface of the water. Shortly, there is possibility of intermittent, partial or total flooding. AD8 grade: Used in locations such as swimming pools, where the electrical equipment is completely covered with water and permanently subjected to a pressure of more than 1 bar. Surrounding environment has the possibility of permanent and total water flooding.

The mechanical protective layer of armored cable can be added to the cable of any structure to increase the mechanical strength of the cable and improve the corrosion resistance. It is designed for the area prone to mechanical damage and corrosion. Armored cables are also divided into steel tape armored cables and steel wire armored cables. The main differences are: 1. Purpose: steel strip armor is only used for laying directly buried cables or ordinary pipes, ordinary ground, tunnels, etc. The thin steel wire armor can withstand the general longitudinal tension, so it is suitable for short distance overhead laying or vertical and vertical laying. In foreign countries, there are many steel wire armored cables! 2. Price: the corresponding steel wire armor is more expensive. Because the production of steel wire armor is difficult and the cost is high. 3. Current-carrying capacity: the difference is not big, but the diamagnetic steel strip or steel wire should be selected. 4. According to the different use environment, different types of armored cables are selected: steel strip armor can withstand mechanical pressure, and steel wire armor can withstand mechanical tension.

Dear customer, Thanks for visiting our website. Thank you for you support all the way through.   Here comes China's Lunar New Year Spring Festival. Kindly note we will be on holiday from January 15th(Sunday) to 27th(Friday).   During holiday, we may have limit access to email and cannot give you quote timely. Kindly ask for your understanding. Once we come back, we will reply you at as quickly as we can.   Happy New Year of Rabbit. Hope you all peace, health and happiness.   Zhenglan Cable Technology Co., Ltd 2023.1.12

5. Remove the faulty lines or equipment from the power system so that the rest can continue to operate. 6. It is prohibited to pull the knife switch with load or close the grounding knife switch with power. The grounding wire shall be removed immediately after the line construction. In addition, the line and its equipment shall be inspected regularly, and problems and failures shall be repaired and maintained in time. 7. Ensure the construction quality of overhead cable lines, strengthen line maintenance, and always keep the line sag consistent and comply with regulations. 8. During live installation and maintenance of electrical equipment, miswiring and misoperation shall be prevented, and measures to prevent short circuit shall be taken when working near the live parts. 9. Strengthen management to prevent small animals from entering the power distribution room and climbing on electrical equipment. Clean the adsorbed dust on the line in time to avoid the dust from entering the electrical equipment and ensure that the line is clean and tidy. For more cable product knowledge, please consult the Cable Treasure Platform.

Dear Sir/Madame,   Happy New Year!!! Hope you and your family will be happy, healthy and all things will go smoothly in the New year.   Your message is well received. But we are on New Year Holiday from December 31st(Saturday) to January 2nd(Monday). We will have limit access to email. We will get back to you at our earliest convenience after come back. Thank you for your kind understading.   Zhenglan Cable Technology Co, Ltd December 30th, 2022

The commonly used methods of power cables and cables are mostly divided into underground direct burial or overhead. However, the small methods to prevent problems with overhead cables are as follows: 1. Do a good job of calculating the short-circuit current, correctly select and calibrate electrical equipment, and make the rated voltage of the electrical equipment consistent with the rated voltage of the line. 2. Correctly select the setting value of the relay protection and the rated current of the melt, and use a quick-break protection device to quickly cut off the short-circuit current when a short circuit occurs, reduce the duration of the short-circuit current, and reduce the losses caused by the short-circuit. 3. Install lightning rods in substations, and lightning arresters near transformers and on lines to reduce lightning damage. 4. Reactors are used to increase system impedance and limit short-circuit current.

1. Different systems are used: DC cables are used in rectified DC transmission systems, and AC cables are often used in power frequency (domestic 50Hz) power systems. 2. Compared with AC cables, DC cables have less power loss during transmission. 3. High transmission efficiency and low line loss. 4. It is convenient to adjust the current and change the direction of power transmission. 5. Although the price of converter equipment is higher than that of transformers, the cost of using cable lines is much lower than that of AC cables. 6. The safety of DC cables is high: ①. The inherent characteristics of DC transmission make it difficult to generate induced current and leakage current, and will not cause electric field interference to other cables laid in the same way. ②. The single-core laying cable will not affect the transmission performance of the cable due to the hysteresis loss of the steel structure bridge. ③ Compared with DC cables with the same structure, it has higher current cut-off capability and over-interruption protection capability. ④. Apply the DC electric field and the AC electric field of the same voltage to the insulator, and the DC electric field is much safer than the AC electric field. 7. The installation and maintenance of the DC cable is simple and the cost is low. Zhenglan Cable Technology Co., Ltd supply cable according to your actual needs. Welcome your inquiry.

The so-called "shielding" on the cable structure is essentially a measure to improve the electric field distribution. The cable conductor is made up of multiple wires twisted, and it is easy to form an air gap between it and the insulating layer. The surface of the conductor is not smooth, which will cause the electric field to concentrate. Add a layer of shielding layer of semi-conductive material on the surface of the conductor, which has the same potential as the shielded conductor and is in good contact with the insulating layer, so as to avoid partial discharge between the conductor and the insulating layer. This layer of shielding is the inner shielding layer.   Also, there may be gaps at the contact between the insulating surface and the sheath, which is a factor that causes partial discharge. Therefore, a layer of semi-conductive material shielding layer is added on the surface of the insulating layer, which has good contact with the shielded insulating layer and is in contact with the metal sheath. Sheath equipotential, so as to avoid partial discharge between the insulation layer and the sheath, this layer of shielding is the outer shielding layer. For extruded insulated cables without metal sheath, in addition to the semi-conductive shielding layer, a metal shielding layer wrapped with copper tape or copper wire should be added. The function of this metal shielding layer is to pass capacitive current during normal operation; When the system is short-circuited, it acts as a channel for short-circuit current and also plays a role in shielding the electric field. It can be seen that if the outer semiconductor layer and copper shielding in the cable do not exist, the possibility of insulation breakdown between the core and the core of the three-core cable is very high.

1. Ordinary flame-retardant wires and cables The insulating and sheathing materials of ordinary flame-retardant wires and cables are generally polymer materials containing halogen (or modified by adding halogen containing flame retardant). Polyvinyl chloride (PVC) is commonly used. Ordinary PVC resin has the characteristics of high electrical insulation, chemical resistance, abrasion resistance, aging resistance and low price. However, when PVC burns, it will release hydrogen chloride, carbon monoxide, carbon dioxide, various aromatic hydrocarbons, chlorinated compounds and other toxic and harmful gases. 2. Low smoke halogen-free flame retardant wire and cable The insulation and sheath materials of low smoke and halogen-free flame-retardant wires and cables are mostly thermoplastic elastomer materials, which do not contain halogens such as fluorine, chlorine, bromine and iodine. Mercury, chromium, cadmium, lead and other heavy metal elements that pollute the environment are excluded from the production process. Polyamide is often used as the material. The flame-retardant mechanism of this cable is that of interrupt switching. Interrupted exchange flame retardant refers to taking away part of the heat generated during the combustion of flame retardant materials, so that the materials can not maintain the thermal decomposition temperature, and therefore can not continue to produce combustible gas, so the combustion is self extinguished.   Zhenglan Cable Technology Co., Ltd manufacture flame retardant wire, low smoke halogen-free flame retardanet wire, fire resistant wire, flame retardant and fire resistant wire. Welcome your inquiry.  

Dear Customer, Thanks for your visiting our website. Kindly note we are on a 7-day National Day holiday from October 1st(Saturday) to 7th(Friday) and will be back from October 8th( Saturday). During holiday, we may have limited access to email and work may be delayed or stop temperaturely. We will contact you the first time we came back. Kindly ask for your understanding. Zhenglan Cable Technology Co., Ltd 2022.9.30

When a single core cable is started or stopped by alternating current or direct current, a corresponding alternating magnetic field will be generated around the cable, and an induced current will be generated in the metal material. This current flows inside the metal material, much like a vortex of water, so it is called eddy current, or eddy current for short. The thermal effect of eddy current can heat the metal materials in a short time. If the heat cannot be emitted in time, it will cause the cable insulation layer to melt or accelerate the aging, and the insulation performance will be weakened, thus causing cable breakdown.   The armored steel strip has good magnetic conductivity, which can be magnetized under a small magnetic field and generate eddy current. Non magnetic materials such as stainless steel tape, copper tape, aluminum tape or non-magnetic metal wire shall be used for armouring of single core cables.   In addition, it is better to lay single core cables in finished form during construction. Single core cables should avoid magnetic materials as far as possible, such as iron pipes, iron clamps, etc., which can form closed loop magnetic materials.   In addition, for a three core cable, the alternating magnetic fields generated by the three core phase relationship cancel each other, so that the sum of the induced current vectors is 0, and no magnetic force lines pass through the armor. Therefore, steel tape armouring can be used.

Dear Customer, Thanks for your visiting our website. Kindly note we are on Mid-Autumn Festival holiday from Sept 10th to 12th. Work resume from Tuesday( Sept, 13th). During holiday, all work will become slow compared with normal days. But we will get back to you as quickly as we can after holiday. Thanks for your support as always. Sincerely yours, Zhenglan Cable Technology Co., Ltd Sept 9th, 2022

Tinned copper wire has a silver appearance because tin is a silver metal. The process of tinned copper wire is a little more complicated than that of bare copper wire. At room temperature, tin is very stable in the air, because a dense oxide film will be formed on the surface of tin to prevent the continued oxidation of tin. Therefore, the copper surface is tinned, the first does not affect the resistance, and the second can improve the oxidation resistance of copper to a certain extent.   The purpose of tinning, silver plating (or even gold plating) for wire and cable conductors is to prevent copper wires from being oxidized and blackened at high temperature and humidity, and to improve conductor solderability and reliability. The operating environment of photovoltaic power plants is generally harsh, and they are often installed in deserts, barren mountains, water surfaces, roofs and other environments. It is required that the resistivity of photovoltaic cables must be good, not easy to oxidize, and can be used for a long time. Therefore, tinned copper wire is selected as the conductor will best fits the use environment and has the most stable electrical performance.   Zhenglan Cable supply power cable, solar cable, feel free to send us your quote.

The main function of the electric wire is not to spread the current to objects outside the target while conducting electricity, which is mainly the function of the insulating layer. Therefore, a good insulation layer is the best guarantee to avoid some risks caused by electricity consumption. The insulation layer is plastic, so we can try to test the plastic method to check the quality of the wire.       So it's easy. Just remember these steps：   1. Pull: If the quality of the insulating layer is poor, it will be easily deformed and cracked when pulling hard. Try to pull as much as possible. It is difficult to judge whether the quality of the insulating layer is good or bad. 2. Folding: Bend a small section of cable at will, if there is no break or white mark at the bend, the quality is good. 3. Ignite: Ignite the wire with fire, and light it with a lighter. If it does not catch fire when it is lit, it is a high-quality wire. It is a good flame retardant wire. If it is lit and emits thick black smoke, it will catch fire on its own after leaving the flame. Don't even think about it. You buy garbage and throw it into the trash can immediately. 4. No odor: It is fake and inferior wire that smells stinky, and the high-quality insulating layer will not have odor that suffocates the nose even if it is ignited.

Power cables are widely used to transmit and distribute electric energy. They are often used in urban underground power grids, outgoing lines of power stations, internal power supply of industrial and mining enterprises, and underwater transmission lines across rivers and seas. The main lines in the power system are generally power cables used to transmit and distribute high-power electric energy, including 1-500kv and above voltage levels. Therefore, the quality of cable products is very important, and the quality and thickness of cable sheath are equally important. What effect does the thickness of cable sheath have on the cable? 1. Affect the service life of power cables The first is the environment. After the construction of power cables, they are basically buried in the ground, immersed in water, in the open air or in an environment prone to corrosion, plus the corrosion of external media for a long time, the insulation level and mechanical level of the thinnest point of the cable sheath will decline. In case of line grounding fault, the thinnest point of cable sheath may be broken down, increasing the hidden danger of safety accidents. The other is the internal consumption of heat energy generated by cables. The cable will produce a lot of heat energy in the process of transmitting electric energy, which is a consumption of the sheath. If the thickness of the cable sheath is not enough, the copper core of the conductor will directly melt the sheath material after heating, which will cause circuit failures and other related safety problems. 2. Impact on Construction According to the current requirements, more and more environmental requirements require that the outer diameter of high-voltage cable products must be small, and it is necessary to consider leaving gaps in the laying process, so as to dissipate the heat generated by the cable after it is powered on. The thickness of the sheath is too thick, which will increase the difficulty of laying, so the thickness of the cable sheath must strictly comply with the relevant national standards, otherwise it cannot protect the cable conductor.

Precautions 1、 Observe the appearance of the wire. The insulation (sheath) layer of qualified products is soft, tough and flexible, and the surface layer is tight, smooth and free of roughness. If the plastic wrapping the wire is easy to peel off, there is a problem of insufficient plastic strength. 2、 It depends on the cross-section of the wire. The surface of copper core or aluminum core of qualified products should have metallic luster. Copper with black surface or aluminum with white surface indicates that it has been oxidized. 3、 Pay attention to check the quality certificate when purchasing wires. If the quality of the wire is qualified, the wire quality should also be tested, and there will be no big problem.

4. Wire and cable with unqualified conductor resistance Conductor resistance is an important indicator for evaluating the compatibility of wire and cable conductor materials and cross-sections. When the conductor resistance exceeds the standard, the loss of the current passing through the line is increased, and the heating of the wire and cable is aggravated. The main reason for the unqualified conductor resistance is that some companies shrink the copper material, which accounts for 80% of the raw material cost, in order to reduce the cost, reduce the cross-sectional area of the conductor or use recycled copper with too high impurities, which causes the conductor resistance of the wire and cable to seriously exceed the standard. , In the process of use, in addition to easily causing fire, it will also accelerate the aging of the insulating layer covering the wire.

The metal shielding methods of medium-voltage XLPE insulated power cables are mainly composed of copper tape overlap wrapping shielding and sparse copper wire shielding. According to the GB/T12706-2008 standard for cables with rated voltage from 6kV to 35kV, the average overlap ratio of copper tape in the copper tape shielding method is not less than 15% of the width of the copper tape (nominal value), and the minimum value is not less than 5%. The thickness of copper tape for single-core cables is ≥ 0. 12mm, the average thickness of multi-core cables is ≥ 0. 10mm, and the minimum thickness of copper tape is not less than 90% of the nominal value. The copper wire shield consists of loosely wound soft copper wires, the surface of which should be fastened by reversely wound copper wires or copper tapes, and the average gap between adjacent copper wires should not be greater than 4mm. The shielding on the cable structure is a measure to improve the distribution of the electric field. The role of the metal shielding mainly has the following aspects: 1. When the cable is normally energized, the metal shielding layer passes the capacitive current, and when the short-circuit fault occurs, the short-circuit current passes. 2. The electromagnetic field caused when the cable is energized is shielded in the insulated core to reduce electromagnetic interference to the outside world, and the metal shielding layer also limits the impact of the external electromagnetic field on the interior. 3. The power station protection system requires the outer metal shield to have better lightning protection properties. 4. Homogenize the electric field to prevent axial discharge. Since the semi-conductive layer has a certain resistance, when the metal shielding layer is poorly grounded, the cable will discharge along the surface due to uneven potential distribution in the cable axis.

3. Wire and cable with aging insulation layer   The unqualified tensile strength and elongation of the insulating sheath before aging directly greatly shortens the working life of the wire and cable, and the insulator is easily broken during construction or in a long-term energized and high-temperature environment, resulting in live conductors. If exposed, there is a risk of short circuit that can cause electric shock. The main reasons for its failure are: first, the use of recycled materials for production to reduce product costs; second, small enterprises that do not have production qualifications cut corners for profit.

2. Wires and cables with unqualified structural dimensions The main problem of the structure size is the thickness of the sheath and the thickness of the insulation. When the sheath and insulation thickness of the cable do not meet the standard, the electrical strength of the wire and cable will be seriously reduced, resulting in a shortened service life of the wire and cable. and cables may break, insulation may not work properly, resulting in electrical shorts and fires.

On May 30, the country's first tidal-light complementary smart photovoltaic power station - National Energy Group Longyuan Zhejiang Wenling Chao-light complementary smart photovoltaic power station achieved full-capacity grid-connected power generation, creating a new energy comprehensive application of photovoltaic and tidal power generation in perfect harmony. This indicates that my country has made new achievements in the comprehensive utilization of marine energy and the three-dimensional development and construction of new energy.   The power station is the first and currently the only Chaoguang complementary smart photovoltaic power station in China. It is located in Wugen Town, Wenling City, Zhejiang Province. Silicon bifacial modules. The power station complements China's largest tidal power station, comprehensively utilizes solar energy and tidal energy, forming a scene of "the sun and the moon work together, and the water and the water generate power together".   It is understood that the level of intelligence and automation of the power station has reached the domestic first-class level, realizing few people and no one on duty. The power station uses UAV inspection technology and AI intelligent diagnosis system, relying on the big data analysis of the digital platform, to carry out remote diagnosis of photovoltaic power generation equipment health monitoring, to detect potential equipment problems in advance, and the early warning accuracy rate is over 85%, reaching the industry's leading position, achieving from The transformation from "people looking for information" to "information looking for people", equipment operation and maintenance has changed from passive to active, which effectively guarantees the economic benefits of the power station.

Dear All, Here comes China's traditional Dragon Boat Festival. We will be on holiday from Friday (June 3rd) to Sunday (June 5th). Work resume from June 6th(Monday). During holiday, we may have limited access to email, so shall any delays of response. Kindly ask for your understanding. Zhenglan Cable Technology Co., Ltd June 1st, 2022

Transmission process The transmission of electric energy, together with power transformation, distribution and consumption, constitutes the overall function of the power system. Through power transmission, the power plants far away (up to thousands of meters) are connected with load centers, so that the development and utilization of electric energy go beyond the regional limits. Transmission lines can be divided into overhead transmission lines and underground transmission lines according to their structural forms. The former consists of line towers, conductors and insulators, which are erected on the ground; The latter is mainly laid underground (or underwater) with cables. Transmission can be divided into DC transmission and AC transmission according to the nature of the transmitted current. This process uses different types or overhead bare conductors such as AAC, AAAC, ACSR, etc. Transformation process In the power system, the power plant converts the natural primary energy into electric energy and sends power to the remote power users. In order to reduce the power loss on the transmission line and the line impedance voltage drop, it is necessary to increase the voltage; In order to meet the security needs of power users, the voltage should be reduced and distributed to each user, which requires a substation that can increase and decrease the voltage and distribute power. Therefore, the substation is an electrical device in the power system that converts voltage, receives and distributes electric energy through it. It is an intermediate link between the power plant and power users. At the same time, the power grid of various voltage levels is connected through the substation. The function of the substation is to transform voltage, transmit and distribute electric energy. The substation is composed of power transformer, power distribution device, secondary system and necessary auxiliary equipment. The transformer is the central equipment of the substation, which uses the principle of electromagnetic induction. This process uses different types of cables such as high voltage, medinum voltage and low voltage power cable, aerial bundled cable, electrical wires.

During the construction of a solar photovoltaic power station, in addition to the main equipment, such as photovoltaic modules, inverters, and step-up transformers, the photovoltaic cable materials connected to the photovoltaic power station have the same effect on the overall profitability, operation safety, and high efficiency of the photovoltaic power station. plays a vital role.. According to the system of solar photovoltaic power station, cables can be divided into DC cables and AC cables. According to the different uses and use environments, they are classified as follows: 1. DC cable (1) Serial cables between components. (2) Parallel cables between the strings and between the strings and the DC distribution box (combiner box). (3) The cable between the DC distribution box and the inverter. The above cables are all DC cables, and there are many outdoor layings. They need to be moisture-proof, sun-proof, cold-resistant, heat-resistant, and UV-resistant. In some special environments, they also need to be protected from chemicals such as acid and alkali. 2. AC cable (1) The connecting cable from the inverter to the step-up transformer. (2) The connecting cable from the step-up transformer to the power distribution device. (3) The connecting cable from the power distribution device to the power grid or the user. This part of the cable is an AC load cable, which is laid in the indoor environment and can be selected according to the general power cable selection requirements. 3. Photovoltaic special cable A large number of DC cables in photovoltaic power plants need to be laid outdoors, and the environmental conditions are harsh. The cable materials should be determined according to the resistance to ultraviolet rays, ozone, severe temperature changes and chemical erosion. The long-term use of ordinary material cables in this environment will cause the cable sheath to be fragile, and even decompose the cable insulation. These conditions will directly damage the cable system, but also increase the risk of short-circuiting the cable. In the medium and long term, the possibility of fire or personal injury is also higher, which greatly affects the service life of the system. 4. Cable conductor material Most of the DC cables used in photovoltaic power plants work outdoors for a long time. Due to the limitation of construction conditions, connectors are mostly used for cable connection. Cable conductor materials can be divided into copper core and aluminum core. 5. Cable insulation sheath material During the installation, operation and maintenance of photovoltaic power plants, cables may be routed in the soil below the ground, in overgrown rocks, on the sharp edges of roof structures, or exposed to the air, and the cables may be impacted by various external forces. If the cable jacket is not strong enough, the cable insulation will be damaged, affecting the service life of the entire cable, or causing problems such as short circuits, fire and personal injury hazards.

Dear All, Wish you a happy International Workers' Day. Hope all of your efforts will be rewarded and all of your hard work will have gains. China's legal holiday for this will be from April 30th(Saturday) till May 4th(Wednesday). Work resume from May 5th( Thirsday). During holiday, we may have limited access to email, so shall any delays of response. Kindly ask for your understanding. Zhenglan Cable Technology Co., Ltd April 30th, 2022  

Power cables are one of the indispensable materials for power transmission and are widely used in economic production. Once a cable fails, it will not only threaten the safe and stable operation of the power grid, but also cause significant economic losses to families and society. Now there are many unqualified cables in the market that are confusing consumers' choices with fake and shoddy cables. The following will introduce the identification method of inferior cables. 1. Unqualified wires and cables   Marking is the main way to identify the basic information of products using wires and cables. According to the standard, the main contents of the mark are: product model, specification, standard, manufacturer, origin, etc. within a certain marking distance. When the mark is unqualified, it will cause Construction personnel identify errors, and in severe cases, construction personnel identify faults that can lead to electrical accidents.  

The rapid development of electric power industry has promoted the development of the electrical industry supporting the electric power industry, especially the wire and cable industry. The variety development of wire and cable shows a diversified trend. Wires and cables have developed from simple power transmission to multi-function, that is, some new characteristics have been added according to different uses, such as the water resistance requirements of power cables. With the deepening of the research and understanding of insulation water absorption and water tree, people are more and more aware of the importance of waterproof performance for medium and high voltage power cables. In areas with high groundwater level or perennial rainfall. More and more users require waterproof performance for cables.   After water is immersed in the cable, the main influence is on the conductor and insulation of the cable. As far as the conductor is concerned, the cable is in a thermal stable state during normal operation, and the conductor temperature is generally above 60. If there is water immersion, it will lead to conductor oxidation and increase the energy loss resistance between conductor single wires, which increases the conductor resistance and the energy loss of transmission line, In terms of insulation, although polyethylene is a non-polar hydrophobic material that is very difficult to dissolve in water, polyethylene is a semi crystalline polymer composed of crystalline phase and amorphous phase. The phase structure of polyethylene is compact, but there are defects at the grain boundary; The molecular arrangement in the amorphous phase is loose. There is a large gap between molecules. Water molecules are polar. Under the combined action of diffusion force and electric field force under alternating electric field, water molecules can easily penetrate into the capacity gap of amorphous phase and grain boundary defects of crystalline phase of polyethylene. The above problems also exist in the molecular structure of cross-linked polyethylene. At the same time, there are many cross-linked by-products in cross-linked polyethylene as impurities, so cross-linked polyethylene also has large water absorption under alternating electric field. Cross linked polyethylene and polyethylene insulation will produce water tree after absorbing water, which will cause breakdown and damage to the running cable.   Zhenglan Cable Technology Co., can do radinal water prevention structure by adding water prevention tape into different layer of the MV cable. If you are looking for such performance for MV cable, please come to us.

Dear Customer, Here comes China's Traditional Qingming Festival, a festival for worshiping ancestors, mourning passed-away relatives, spring outings. We will be on holiday from Sunday(April 3rd) to Tuesday(April 5th). Work resume on Wednesday(April 6th). During holiday, we may have limit access to email. Shall any delays of response, kindly ask for your understanding. Regards Zhenglan Cable Technology Co., Ltd. April 2nd, 2022

Shielded control cable is generally used as the connecting line of electrical instruments, which is suitable for the connecting line of electrical instruments with AC rated voltage of 450 / 750V and below and the transmission line of automatic control system. It has excellent properties such as oil resistance, waterproof, wear resistance, acid and alkali resistance, various corrosive gases, aging resistance and non combustion. Shielded control cable is a cable with a layer of mesh copper wire or metal wire braided around one or more wires. This layer of mesh wire can prevent lightning stroke, and external signals can not interfere with its. The shielding layer can also play a certain role in leakage protection. If the cable is damaged and electric leakage occurs during use, the shielding layer can lead the leaked current to the grounding wire, which plays a certain role in safety protection. At the same time, it can also protect the cable conductor. The function of shielding layer and grounding wire of shielding control cable is: the shielding layer is divided into internal shielding and external shielding. They are all designed to make good contact between the cable conductor and the insulating layer, and between the cable insulating layer and the inner protective layer, so as to eliminate the increase of surface electric field intensity caused by the unsmooth surface of the conductor and the inner protective layer Service characteristics of shielded control cable: (1) Allowable bending radius of cable: the minimum bending radius of non armored cable is 6 times of the outer diameter of the cable. Fluoroplastic insulated and sheathed cables shall be at least 8 times of the outer diameter of the cable. Copper tape shielded or steel tape armored cable shall be at least 12 times of the outer diameter of the cable. (2) Maximum working temperature: the insulation of polyperfluoroethylene propylene (F46) shall not exceed 200 ℃. Soluble polytetrafluoroethylene (PFA) insulation shall not exceed 260 ℃. (3) Minimum ambient temperature: PVC sheath: fixed laying - 40 ℃, non fixed laying - 15 ℃. Fluoroplastic and silicone rubber sheath: fixed laying - 60 ℃, non fixed laying - 20 ℃. The cable installation and laying temperature shall not be lower than 0 ℃ (fluoroplastic, silicone rubber and nitrile sheathed cable shall not be lower than - 25 ℃).

This question is wrong, and aluminum also rusts, but when aluminum rusts, it does not rust like iron until it is completely rusted. ​​  The oxidation of metal by oxygen in the air is rust. Aluminum reacts chemically with oxygen to form aluminum oxide, which is aluminum rust. Aluminum rust is very thin, its thickness is only ten thousandths of a millimeter, but it is very hard and very wear-resistant. It clings to the surface of the aluminum so that the aluminum inside is not exposed to the outside air, preventing the aluminum from continuing to rust.

Low-smoke halogen-free flame-retardant cables have flame-retardant properties, and the ignition delay is only limited to a certain range. It also has low smoke and harmlessness, little smoke when burning, and no corrosive gas escapes.   In addition to transmitting power under normal working conditions, the low-smoke halogen-free fire-resistant cable can still maintain normal operation for a certain period of time when it is on fire. Building fire protection system, emergency lighting system, life-saving system, alarm and important monitoring circuit, etc.

1. Low-smoke halogen-free wire refers to the environmentally friendly wire that does not contain halogen, lead, cadmium, chromium, mercury and other environmental substances. It will not emit toxic fumes when burning, and will not produce secondary hazards. It meets the requirements of modern fire safety. ..   2. The maximum rated temperature can reach 90℃ during long-term operation, and the maximum temperature of the wire conductor can reach 250℃ during short circuit (the longest duration does not exceed 5S), and the current carrying capacity is greater than that of PVC insulated wires.   3. The outer diameter of this kind of wire is smaller than the outer diameter of the full PVC insulated wire of the same specification and cross-section. In the construction of the pipe, the diameter of the pipe can be reduced, or more wires can be passed under the condition of the same pipe diameter, so as to reduce the construction and installation cost. .

1. Low resistivity: the resistivity of aluminum core cable is about 1.68 times higher than that of copper core cable.   2. Good ductility: the ductility of copper alloy is 20 ~ 40%, that of electrical copper is more than 30%, and that of aluminum alloy is only 18%.   3. High strength: the allowable stress of copper is 7 ~ 28% higher than that of aluminum at room temperature. Especially the stress at high temperature, the difference between the two is very far.   4. Fatigue resistance: aluminum is easy to break after repeated bending, while copper is not. In terms of elasticity index, copper is also about 1.7 ~ 1.8 times higher than aluminum. (low voltage power cable, medinum voltage power cable)   5. Good stability and corrosion resistance: copper core is resistant to oxidation and corrosion, while aluminum core is vulnerable to oxidation and corrosion.   6. Large current carrying capacity: due to low resistivity, the allowable current carrying capacity (maximum current that can be passed) of copper core cable with the same section is about 30% higher than that of aluminum core cable   7. Low voltage loss: due to the low resistivity of copper core cable, when the same current flows through the same section. The voltage drop of copper core cable is small. The same transmission distance can ensure high voltage quality; Under the condition of allowable voltage drop, the transmission of copper core cable can reach a long distance, that is, the power supply coverage area is large, which is conducive to network planning and reduce the number of power supply points.   8. Low heating temperature: under the same current, the heating capacity of copper core cable with the same section is much smaller than that of aluminum core cable, making the operation safer. (Aluminum conductor steel reinforced, ACSR)   9. Low energy consumption: due to the low resistivity of copper, compared with aluminum cable, the power loss of copper cable is low, which is obvious. This is conducive to improving the utilization rate of power generation and protecting the environment.   10. Oxidation resistance and corrosion resistance: the connector of copper core cable has stable performance and will not cause accidents due to oxidation. The joint of aluminum core cable is unstable, and accidents often occur due to the increase of contact resistance and heating due to oxidation. Therefore, the accident rate is much higher than that of copper core cable.   11. Convenient construction: The copper core has good flexibility and small allowable bending radius, so it is convenient to turn and pass through the pipe; The copper core is anti fatigue and not easy to break after repeated bending, so the wiring is convenient; The copper core has high mechanical strength and can bear large mechanical tension, which not only brings great convenience to the construction and laying, but also creates conditions for mechanized construction. (overhead insulated cable, electrical control cable)

Dear Customer, Happy new year!!!   We will be on traditional Chinese lunar new year Spring Festival Holiday from January 29th to February 6th. Work resume from February 7th(Monday). During holiday, all work maybe affected somehow and we may have limit access to email. So for any delay of response, kindly ask for your understanding.   Hope you all have a happy time with your family.   Zhenglan Cable Technology Co., Ltd 2022-01-27

1. The systems used are different. DC cables are used in rectified DC transmission systems, and AC cables are often used in power frequency (domestic 50Hz) power systems. 2. Compared with the AC cable, the power loss in the transmission process of the DC cable is smaller. The power loss of the DC cable is mainly the DC resistance loss of the conductor, and the insulation loss is small (the size depends on the current fluctuation after rectification); while the AC resistance of the low-voltage AC cable is slightly larger than the DC resistance, and the high-voltage cable is obvious, mainly because Proximity effect and skin effect, the loss of insulation resistance accounts for a large proportion, mainly the impedance generated by capacitance and inductance. 3. High transmission efficiency and small line loss. 4. It is convenient to adjust the current and change the direction of power transmission. 5. Although the price of converter equipment is higher than that of transformers, the cost of using cable lines is much lower than that of AC cables. The DC cable has positive and negative poles, and the structure is simple; the AC cable is three-phase four-wire or five-wire system, which requires high insulation safety and complex structure, and the cable cost is more than three times that of the DC cable. 6. DC cables are safe to use 1) Due to the inherent characteristics of DC transmission, it is difficult to generate induced current and leakage current, and it will not cause electric field interference to other cables laid in the same way. 2) The single-core laying cable will not affect the transmission performance of the cable due to the hysteresis loss of the steel structure bridge. 3) It has higher current interception capability and over-interruption protection capability than DC cables of the same structure. 4) Direct and alternating electric fields of the same voltage are applied to the insulation, and the direct electric field is much safer than the alternating electric field. 7. The installation and maintenance of the DC cable are simple and the cost is low.

The Christmas holiday is coming near . We would like to extend our warm wishes for the upcoming holiday season and would like to wish you and your family a Merry Christmas and a prosperity in the year ahead   Zhenglan Cable Technology Co., Ltd will continue to give you our best products and excellent service. Thank you for your support and help along the way. Hope the next year is a prosperous and harvest year for both of us!  Regards

1. The principle of wire selection The conductor and ground wires of power transmission lines operate in the wilderness, mountainous areas or the edge of lakes and seas for a long time, and need to withstand the effects of external loads such as wind and ice, drastic changes in temperature and attack by chemical gases, etc., and are also subject to national resources and line costs And other factors. Therefore, in the design, especially for large spans, the material and structure of the wires must be carefully selected. Generally, the following principles should be considered when selecting the material and structure of the wire: ⑴ The conductor material should have high conductivity. However, considering national resources, copper wires should not be used in general. ⑵The conductor and ground wire should have high mechanical strength and vibration resistance. ⑶ The conductor and ground wire should have certain chemical resistance and oxidation resistance. ⑷ When choosing the wire material and structure, in addition to meeting the transmission capacity, the cost of the line should be economical and technically reasonable. 2. Selection of wire cross section The cross section of the overhead transmission line conductor is generally selected according to the economic current density, and should be checked according to the heating conditions, voltage loss, mechanical strength and corona in the event of an accident. When necessary, it is determined through technical and economic comparison; but for lines of 110KV and below, corona is often not the decisive factor in selecting the conductor cross section. 1) Choose the wire section according to the economic current density According to the economic current density to select the transmission capacity used for the conductor cross-section, the development plan of the power system should be considered for 5-10 years after the line is put into operation. In the calculation, the maximum load that frequently recurs under the normal operation mode must be adopted. But when the system is not clear, care should be taken not to make the wire cross section too small. 2) Check the cross-section of the wire according to the corona condition With the continuous increase of operating voltage in my country, the probability of corona and discharge of wires, insulators and fittings has increased. For the cross-section of wires of 220KV and above voltage lines, corona conditions often play a major role. The corona generated by the wire will bring about two undesirable consequences: ① It increases the power loss of the power transmission line; ② It interferes with radio communication and carrier communication. Regarding the corona loss, if the corona loss of the transmission line is directly calculated, the advantage is that the concept of quantity is very clear, but the disadvantage is that the calculation is cumbersome. This method is rarely used at present. It tends to be measured by the ratio of the maximum working electric field strength Em (unit: KV/cm) of the wire to the critical electric field strength E0 of the overall corona. The ratio of Em/E0 should not be greater than 80%-85%.

Elastic coefficient is also called elastic modulus. Elastic modulus is not only an important factor affecting cable stiffness, but also an important physical quantity affecting the operating tension of overhead wire and cable. The elastic modulus of overhead conductor is not only related to the material, but also closely related to the structure of conductor, such as the number of strands of conductor and the process parameters of strand.  The exact elastic modulus of conductor should be determined by tensile test, so it is often said that there are initial and final values, while the test report often only gives "measured values".   The coefficient of expansion is sometimes called linear elasticity, which refers to the percentage of the change in the length of the material for every 1 ℃ change in temperature, also known as the coefficient of linear expansion. When the temperature of a solid substance changes by 1 ℃, the ratio of the change of its length to its length at 0 ℃ is called "coefficient of linear expansion". Due to different substances, the linear expansion coefficient is also different, and its value is also related to the actual temperature and the reference temperature selected when determining length 1. However, because the linear expansion coefficient of solid changes little, it can be ignored, and a is regarded as a constant independent of temperature.

1. Color: The cost-effective copper core is rose red, with a bright surface and no burrs. However, the marking quality of those wires without light and dark surfaces is not good. 2, insulation layer: the thinnest point and symmetrical thickness of the wire insulation layer in our country have clear data specifications, so the thickness of the reliable wire insulation layer is a symmetrical, unbiased iron core, and pressed tightly on the conductor; 3. Wire core: Cost-effective wire is usually produced from pure copper raw materials, and undergoes strict wire drawing, annealing and hanging wire core. Its surface should be bright, slippery, tight, flat, soft, durable and not easy to crack;

With the development of society and the continuous improvement of living standards, both domestic and industrial electricity consumption is increasing, and the frequency of cable replacement is gradually increasing. Then many people do not know whether the used cables can be recycled. In fact, some of the used cables can be recycled. Recycling, what are the used cables that can be recycled?   Recyclable waste cables can be divided into bare wires, insulated wires, heat-resistant wires, shielded wires, power cables, control cables, communication cables, radio frequency cables, etc. according to their uses.

The safe current carrying capacity of 2.5 mm2 copper power line is - 28a. Safe current carrying capacity of 4mm2 copper power line - 35A. Safe current carrying capacity of 6 mm2 copper power line - 48A. The safe current carrying capacity of 10 mm2 copper power line is - 65A. The safe current carrying capacity of 16 mm2 copper power line is - 91A. Safe current carrying capacity of 25 mm2 copper power line - 120a. In case of aluminum wire, the wire diameter shall be 1.5-2 times that of copper wire. If the copper wire current is less than 28a, take 10A per square millimeter for safety. If the copper wire current is greater than 120a, take 5A per square millimeter.

Analyze the reasons for the unqualified wires and cables for everyone：   Marking is the main way for wires and cables to identify the basic information of products. According to standard regulations, the main content of the mark is: product model, specification, standard number, factory name, place of origin, etc. within a certain mark interval. When the mark is unqualified, it will cause the construction personnel's identification error, and in serious cases, it may cause electrical accidents.

1. Select the cable cross-sectional area according to the long-term allowable current-carrying capacity 1.1 In order to ensure safety and the service life of the cable, the temperature of the cable after power-on should not exceed the specified long-term allowable working temperature. The temperature is 70 degrees for polyvinyl chloride insulated cables and 90 degrees for XLPE insulated cables. According to this principle , It's very simple to look up the table and choose the cable. 1.2 Examples: A certain factory has a transformer capacity of 2500KVa and uses 10KV power supply. If XLPE insulated cables are used to lay in the bridge, what is the cross-sectional area of ​​the cable? Step 1: Calculate the rated current 2500/10.5/1.732=137A Step 2: Check the cable selection manual to know YJV-8.7/10KV-3X25 current carrying capacity is 120A YJV-8.7/10KV-3X35 current carrying capacity is 140A Step 3: Choose YJV-8.7/10KV-3X35 with a cable carrying capacity greater than 137A, which can theoretically meet the requirements. Note: This method does not consider the requirements of dynamic stability and thermal stability. 2. Choose the cable cross-sectional area according to the economic current density Simply understand the economic current density. The cross-sectional area of ​​the cable affects the line investment and power loss. In order to save investment, it is hoped that the cable cross-sectional area should be smaller; in order to reduce the power loss, it is hoped that the cable cross-sectional area should be larger; based on the above considerations, determine a reasonable one The cross-sectional area of ​​the cable is called the economic cross-sectional area, and the corresponding current density is called the economic current density. 3. Select the cable cross-sectional area according to the voltage drop of the power grid When we use the first and second methods to select the cross-sectional area of ​​the cable, if the cable is very long, a certain voltage drop will occur during operation and startup, and the voltage on the device side will be below a certain range, which will cause the device to heat up. 4. Select the cross-sectional area of ​​the cable according to the thermal stability coefficient (that is, select the cross-sectional area of ​​the cable according to the short-circuit current) 4.1 When the 0.4KV cable is protected by an air switch, the general cable can meet the thermal stability requirements, so there is no need to verify it according to this method. 4.2 For cables above 6KV, after selecting the cross-sectional area of ​​the cable using the above method, you must verify whether it meets the thermal stability requirements according to the following formula. If it does not meet the requirements, choose a larger cross-sectional area. Formula: Smin=Id×√Ti/C Among them, Ti is the breaking time of the circuit breaker, which is 0.25S, C is the thermal stability coefficient of the cable, which is 80, and Id is the three-phase short-circuit current value of the system. For example: when the system short-circuit current is 18KA, how to choose the cable cross-sectional area. Smin=18000×√0.25/80=112.5 Conclusion: If the system short-circuit current reaches 18KA, even if the rated current of the equipment is smaller, the cable cross-sectional area should not be less than 120mm2.

Dear all, With the National Day holiday, the specific arrangements for our National Day holiday are hereby notified as follows: Holiday time: 7days in total from October 1st to October 7th, 2021. During holiday, we may have limited access to email so for any of the delay of response of your email, kindly ask for your understading. After holiday,we will respond it  as soon as possible once we resume work. Best wishes Zhenglan Cable Technology Co., Ltd