China Zhenglan Cable Technology Co., Ltd Company News

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.