China Zhenglan Cable Technology Co., Ltd Company News

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.

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.