China Zhenglan Cable Technology Co., Ltd Company News

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 ℃).

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. .

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.

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.