China Zhenglan Cable Technology Co., Ltd Company News

11. What should be stated on the cable sign? What are the requirements for writing? Answer: The cable line design number, cable model, specification and starting point should be indicated on the signboard. Cables used in parallel should have sequence numbers. The handwriting is required to be clear and not easy to fall off.   12. How should the yellow wax silk ribbon, black glass paint ribbon, alkali-free glass ribbon, etc. used for making cable joints be dehumidified before construction? Answer: ① Constant temperature drying method: roll the insulating tape into a small roll with a diameter of 25~30mm, put it into a constant temperature drying oven at 110~120℃ for 4~5 hours, cool and dry, take it out, and put it into a dry sealed cylinder. ②Oil immersion moisture drainage method: Put the small roll of insulation tape into the cable oil with a constant temperature of 120~130℃, keep a distance of 30mm from the bottom of the pot. After a certain period of time, the oil surface will no longer produce foam, take it out, and put it into the stored cable. In oil barrels, the oil level should exceed all contained objects and be sealed. 13. What is the function of the cable outer sheath? Answer: Protect the inner protective layer from mechanical damage and chemical corrosion and enhance mechanical strength. 14. What requirements should outdoor cable trenches meet? Answer: The upper part of the cable trench should be slightly higher than the ground and covered with a concrete cover. The cables should be laid flat on the bracket and have good drainage pipes.   15. What is the function of the inner sheath of the cable? Answer: Keep the insulation layer from coming into contact with water, air or other objects, prevent the insulation from getting damp and prevent the insulation layer from mechanical damage.   16. What should you pay attention to when using wire cutters? Answer: Before use, be sure to check whether the insulation of the insulated handle is intact. Do not use wire cutters to cut metal wires exceeding the specifications allowed. It is also prohibited to use wire cutters instead of hammers to hit the tool to avoid damage.   17. What is insulation strength? Answer: When an insulating material is in an electric field, it will be broken down when the electric field intensity increases to a certain limit. This electric field intensity that leads to insulation breakdown is called insulation strength.

Armored cables are made of conductors of different materials installed in metal casings with insulating materials, and are processed into a flexible and solid assembly. The mechanical protective layer of armored cables can increase the mechanical strength of the cable and improve its corrosion resistance. It is a cable designed for areas prone to mechanical damage and erosion. It can be laid in any way, and is more suitable for direct burial in rocky areas. Armored cables are also divided into steel tape armored cables and steel wire armored cables.   1. Purpose: Steel tape armor is only used for the laying of directly buried cables or ordinary pipes, ordinary ground, tunnels, etc. The thin steel wire armor can withstand general longitudinal tension, so it is suitable for short-distance overhead laying or vertical and vertical laying. Abroad, there are more steel wire armored cables!   2. Price: The corresponding steel wire armor is more expensive. Because steel wire armor is difficult to produce and the cost is high.   3. Current-carrying capacity: There is not much difference, but they must use countermagnetic steel strips or steel wires.   4. Depending on the use environment, choose different forms of armored cables: steel tape armor can withstand mechanical pressure, and steel wire armor can withstand mechanical tension.   Zhenglan Cable can do both types of armored cable. Welcome your inquiry.

Dear Customer,   Thanks for your visiting our website.   Please be informed that our company will remain closed from September 29th to October 6th due to the National Day holidays Normal business will resume on October 7th. We apologize for any inconvenience caused by our temporary closure and appreciate your understanding.   Zhenglan Cable Technology Co., Ltd 2023.9.28

6. What regulations should be followed when selecting the cross-section of power cables? Answer: The selection of power cables should follow the following principles: (1) The rated voltage of the cable must be greater than or equal to the rated voltage of the power supply system at the installation point; (2) The continuous allowable current of the cable should be equal to or greater than the maximum continuous current of the power supply load; (3) The wire core cross-section must meet the stability requirements of the power supply system during short circuit; (4) Check whether the voltage drop meets the requirements based on the cable length; (5) The minimum short-circuit current at the end of the line should enable the protective device to operate reliably.   7. What are the advantages of cross-linked polyethylene cables and oil-paper cables? Answer: (1) Easy to install because it allows a small minimum bending radius and is lightweight; (2) Not affected by line differences; (3) Good thermal performance, allowing high operating temperature and large transmission capacity; (4) The cable accessories are simple and all are dry structures; (5) Operation and maintenance are simple and there is no oil leakage problem; (6) The price is lower; (7) High reliability and low failure rate; (8) Few manufacturing steps, simple process, and significant economic benefits.   8. What are the requirements for clamps for fixing AC single-core cables? Why? Answer: The clamp should have no iron parts to form a closed magnetic circuit. This is because when the cable core passes current, magnetic lines of force are generated around it. The magnetic lines of force are proportional to the current passing through the core. If magnetically conductive materials such as iron parts are used, according to It can be seen from electromagnetic induction that eddy currents will be generated in the iron parts to cause the cable to heat up and even burn the cable. Therefore, iron parts cannot be used as fixed fixtures for single-core AC cables.   9. What are the biggest features and advantages of heat shrinkable cable head accessories? Answer: The biggest feature of heat shrink accessories is that they use stress tubes instead of traditional stress cones. It not only simplifies the construction process, but also reduces the size of the joint terminals. It is easy to install, saves time and labor, has superior performance, and saves metal. Heat-shrinkable cable accessories are both potted and dry-packed, combining the advantages of both types of accessories.   10. What inspections should be carried out before laying cables? Answer: (1) The brackets should be complete and the paint should be complete. (2) The cable model, voltage, and specifications comply with the design. (3) The cable insulation is good. When there is doubt about the sealing of oil-paper cables, moisture judgment should be made; directly buried cables and small bottom cables should pass the DC withstand voltage test; oil samples of oil-filled cables should pass the test. (4) The oil pressure of oil-filled cables should not be lower than 1.47MPa.

1. What are the types of commonly used wires and cables according to their uses? Answer: According to the purpose, it can be divided into bare wires, insulated wires, heat-resistant wires, shielded wires, power cables, control cables, communication cables, radio frequency cables, etc. 2. What kinds of insulated wires are there? Answer: Common insulated wires are as follows: PVC insulated wire, PVC insulated flexible wire, nitrile polyvinyl chloride mixture insulated flexible wire, rubber insulated wire, agricultural underground direct buried aluminum core plastic insulated wire, rubber insulated cotton yarn Textile flexible wires, PVC insulated nylon sheathed wires, PVC insulated flexible wires for electricity and lighting, etc.   3. What are the cable accessories? Answer: Commonly used electrical accessories include cable terminal junction boxes, cable intermediate junction boxes, connecting pipes and terminals, steel plate junction slots, cable trays, etc.   4. What is the cable intermediate joint? Answer: The device that connects the conductor, insulation shielding layer and protective layer of the cable to the cable to connect the cable line is called the cable intermediate joint.   5. What aspects should be considered when selecting the cross section of the power cable? Answer: The following aspects should be considered: (1) The working current that the cable is allowed to pass through for a long time; (2) thermal stability in case of short circuit; (3) The voltage drop on the line cannot exceed the allowable working range.

Concentric Conductor Shielded Neutral Power Cable has advantages as below: 1. When the power is transmitted, it will not interfere with the surrounding electrical equipment; it also eliminates the impact of external electromagnetic interference on the electrical equipment connected to the cable. 2 It can avoid breakdown or damage caused by strong lightning electromagnetic effect voltage, and improve the lightning protection effect and reliability of high-rise buildings. 3. It can improve the sensitivity of the overcurrent protection device at the hand end of the line, so that the cable and the electrical equipment connected to it can be effectively protected. 4. It has low and uniform positive (reverse) sequence and zero sequence impedance, which is beneficial to improve the quality of copper electricity. 5. The grounding fault caused by one-phase insulation breakdown can be eliminated as soon as possible.