Answers to common questions about wire and cable

In this paper, from the basic knowledge of wire and cable, cable laying problems, cable protection regulations, cable classification problems, cable laying mode, cable laying specific requirements, and cable related problems in seven aspects of detailed answers to 80 common questions, suggested industry colleagues to collect for reference!

1. What kinds of wires and cables are commonly used?

Answer: it can be divided into bare wire, insulated wire, heat-resistant wire, shielded wire, power cable, control cable, communication cable, radio frequency cable, etc.

2. What kinds of insulated wires are there?

Answer: often the insulated wire has the following kinds: PVC insulated wire, PVC insulated flexible wire, nitrile soft PVC compounds insulation wire, rubber insulated wire, agricultural underground buried plastic insulation aluminum core wire, rubber insulation cotton textile soft wire, PVC insulated nylon sheathed wire, electric power and lighting soft PVC insulated wire and so on.

3. What occasions is the cable bridge suitable for?

Answer: Cable tray is suitable for laying power cables and control cables indoors and outdoors in general industrial and mining enterprises, and can also be used for telecom, radio and television departments to set up indoors and outdoors.

4. What are the cable accessories?

Answer: Commonly used electrical accessories include cable terminal junction box, cable intermediate junction box, connecting pipe and wiring terminal, steel plate wiring slot, cable bridge, etc.

5. What is the cable intermediate joint?

Answer: The device that connects the cable with the conductor, insulation shield and protective layer of the cable so that the cable line can be connected is called cable intermediate connector.

6, what is the main electrical wiring?

Answer: The main electrical wiring is the connection mode of the main electrical equipment and bus in the power plant and substation, including the connection mode of the main bus and the auxiliary power system according to certain functional requirements.

7. What regulations should be followed when selecting the cross-section of 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 allowable continuous current of the cable shall be equal to or greater than the maximum continuous current of the power supply load;

(3) The core section should meet the stability requirements of the power supply system in case of short circuit;

(4) Check whether the voltage drop meets the requirements according to the cable length;

(5) The minimum short-circuit current at the end of the line should enable the protection device to operate reliably.

8. What are the advantages of xLPE cable and oil paper cable?

Answer :(1) easy to install because it allows a small minimum bending radius and light weight;

(2) not limited by line drop;

(3) Good thermal performance, high allowable working temperature, large transmission capacity;

(4) Cable accessories are simple and are dry structure;

(5) Simple operation and maintenance, no oil leakage problem;

(6) Low price;

(7) High reliability and low failure rate;

(8) Less manufacturing process, simple process, significant economic benefits.

9. What are the requirements for fixing the clip of ac single core cable? Why is that?

Answer: fixture should be no iron to form a closed magnetic circuit, this is because when the cable core through the current, in its surrounding magnetic force lines, magnetic force lines and through the core of the current is proportional to the size, if the use of iron and other magnetic materials, according to electromagnetic induction, will produce eddy current in the iron to make the cable heat, or even burn out the cable. Therefore, iron pieces can not be used as a single - core AC cable fixture.

10. What are the biggest features and advantages of the following accessories of the heat-shrinkable cable head?

Answer: the biggest characteristic of heat shrinkable accessory is to replace the traditional stress cone with the stress tube, which not only simplifies the construction process, but also reduces the size of the terminal of the joint. It is easy to install, time-saving, labor-saving, superior performance and metal saving. Heat shrinkable cable accessories are integrated with perfusion type and dry wrap type, combining the advantages of the two accessories.