China Zhenglan Cable Technology Co., Ltd Company News

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