Simple learning about cables
1. What types of commonly used wires and cables are classified according to their uses?
Answer: According to use, 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 types of insulated wires are there?
Answer: Commonly used insulated wires include the following: PVC insulated wires, PVC insulated flexible wires,
nitrile-PVC mixture insulated flexible wires, rubber insulated wires, agricultural directly buried underground
aluminum core plastic insulated wires, rubber insulated cotton yarn Textile cords, PVC insulated nylon
sheathed wires, PVC insulated cords for power and lighting, etc.
3. What kind of occasions is the cable tray suitable for?
Answer: Cable trays are suitable for overhead laying of power cables and control cables indoors and
outdoors 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 accessories?
Answer: Commonly used electrical accessories include cable terminal boxes, cable intermediate junction boxes,
connecting pipes and terminal blocks, steel plate wiring troughs, cable trays, etc.
5. What is a cable intermediate joint?
Answer: The device that connects the conductor, insulation shielding layer and protective layer of
the cable to connect the cable lines is called the cable intermediate joint.
6. What is electrical main wiring?
Answer: Electrical main wiring is the connection method of main electrical equipment and
busbars in power plants and substations, including the connection method of main busbars
and plant power systems according to certain functional requirements.
7. 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.
8. 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 light weight;
(2) Not subject to 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) Simple operation and maintenance, no oil leakage problem;
(6) Lower price;
(7) High reliability and low failure rate;
(8) Few manufacturing steps, simple process, and significant economic benefits