China Zhenglan Cable Technology Co., Ltd Company News

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.