Questions and answers about the basic knowledge of wire and cable

Abstract: Q&A information about the basic knowledge of wires and cables is provided by excellent flowmeter and flowmeter production and quotation manufacturers. 1. What are the commonly used wires and cables according to their uses? Answer: It can be divided into bare wires, insulated wires, heat-resistant wires, shielded wires, power cables, control cables, communication cables, radio frequency cables, rubber sheathed cables, mining cables, underwater cables, etc. For more flowmeter manufacturers to select models and price quotations, you are welcome to inquire. The following is the details of the Q&A article about the basic knowledge of wires and cables. 1. What are the commonly used wires and cables according to their uses? Answer: It can be divided into bare wires, insulated wires, heat-resistant wires, shielded wires, power cables, control cables, communication cables, radio frequency cables, rubber sheathed cables, mining cables, underwater cables, cold-resistant cables, etc. 2. What types of insulated wires are there? Answer: Commonly used insulated wires are the following types: material insulated flexible wire, rubber sheathed insulated wire, underground direct buried aluminum core plastic insulated wire, rubber insulated cotton yarn textile flexible wire, PVC insulated nylon sheathed wire, plastic insulated wire for power and lighting Vinyl chloride insulated cord, etc. 3. What occasions is the cable tray suitable for? Answer: The cable tray is suitable for indoor and outdoor overhead laying of power cables and control cables in general industrial and mining enterprises, and can also be used for indoor and outdoor erection in telecommunications, radio and television and other departments. 4. What are the cable and cable accessories? Answer: Commonly used wire and cable accessories include cable terminal junction boxes, cable intermediate junction boxes, connecting pipes and terminals, steel wiring troughs, cable trays, etc. 5. What is a wire and cable intermediate joint? Answer: The device that connects the cable with the conductor, insulating shielding layer and protective layer of the cable to connect the cable line is called the cable intermediate joint. 6. What is the electrical main wiring? Answer: The electrical main wiring refers to the connection method of the main electrical equipment and the busbar in the power plant and substation, including the connection method of the main busbar and the power system of the plant according to certain functional requirements. 7. What regulations should be followed when choosing the cross-sectional area of ​​the power cable? Answer: The selection of power cables should follow the following principles: (1) The rated voltage of the cable should 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 cross section of the wire core should meet the requirements of the stability of the power supply system during short circuit; (4) Check whether the voltage drop meets the requirements according to the length of the cable; (5) The minimum short-circuit current at the end of the line should make the protection device reliable. action. 8. What are the advantages of XLPE cable compared with oil-paper cable? Answer: The advantages are: (1), easy to install, because of its small allowable minimum bending radius and light weight; (2), not limited by the drop of the line; (3), good thermal performance, allowing high operating temperature, transmission Large capacity; (4), simple cable accessories, all of which are dry structure; (5), simple operation and maintenance, no oil leakage problem; (6), relatively low price; (7), high reliability, low failure rate; (8) The manufacturing process is few, the process is simple, and the economic benefit is remarkable. 9. Regarding the fixture for fixing the AC single-core cable Answer: The fixture should have no iron parts to form a closed magnetic circuit, because when the cable core passes current, magnetic lines of force are generated around it, and the magnetic lines of force are proportional to the current through the core. Magnetically conductive materials such as iron parts, according to electromagnetic induction, will generate eddy currents in the iron parts, which will cause the cable to heat up and even burn out the cable. Therefore, it is not possible to use iron as a fixing fixture for single-core AC cables. 10. The biggest features and advantages of the accessories of the heat-shrinkable cable head A: The heat-shrinkable accessories replace the traditional stress cone with a stress tube, which not only simplifies the construction process, but also reduces the size of the terminal of the connector, which is easy to install and saves time and labor. , Superior performance, saving metal. The heat shrinkable cable accessory integrates the pouring type and the dry wrapping type, combining the advantages of these two types of accessories. 11. Inspection work that should be carried out before cable laying Answer: (1) The bracket should be complete and the paint is complete. (2) The cable model, voltage and specifications must conform to the design. (3) The cable insulation is good. When there is doubt about the sealing of the oil-paper cable, it should be judged by moisture; the direct-buried cable and the small bottom cable should be difficult to pass the DC withstand voltage test; the oil sample of the oil-filled cable should pass the test. (4) The oil pressure of the oil-filled cable should not be lower than 1.47MPa. 12. When there is doubt about the sealing of oil-paper-insulated power cables, how to use a simpler method to check whether the cable insulating paper is damp? Answer: Ignite the cable insulation paper or put it in the cable oil at about 150 ℃ to check, no“hiss”Sound or white foam appears, indicating that it is not damp. 13. Cable sign A: The cable line design number, cable model, specification and starting point should be indicated on the cable sign. The cables used in parallel should have sequence numbers. The handwriting is required to be clear and not easy to fall off. 14. Where should the orientation mark of the directly buried cable be set? Answer: At both ends of the cable, the cable joints and the corners where the cable changes direction at 50~100m of the straight section of the cable. 15. How to remove moisture before construction for yellow wax ribbons, black glass paint ribbons, alkali-free glass ribbons, etc. used for making cable joints? Answer: (1) Constant temperature drying method: Roll the insulating tape into small rolls with a diameter of 25~30mm, put it in a constant temperature drying box of 110~120℃ for 4~5 hours, cool it and dry it out, and put it in a dry sealed cylinder.

However, mass flow meter isn't the only producer in domestic, and many people feel that Beijing Sincerity Automatic Equipment Co., Ltd's service leaves much to be desired in terms of functionality and design.

To learn more about mass flow meter， give us a call at Beijing Sincerity Automatic Equipment Co., Ltd or visit us online by going to Sincerity Flow Meter.

Although the core manufacturing factor of mass flow meter is high technology, smart customers know that we need to enhance our material quality and producing standard.

Beijing Sincerity Automatic Equipment Co., Ltd deems mass flow meter as evolutionary rather than revolutionary. We've always had these 'social commerce' marketplaces in some form.

Time is one of the biggest challenges cited by manufacturing mass flow meter.