Eight precautions for power cords

1. Classification of insulated wires

Common insulated wires are as follows: PVC insulated wires, PVC insulated flexible wires, nitrile polyvinyl chloride mixture insulated flexible wires, rubber insulated wires, agricultural underground direct buried aluminum core plastic insulated wires, rubber insulated cotton yarn textile soft wires Wires, PVC insulated nylon sheathed wires, PVC insulated flexible wires for power and lighting, etc.

 

2. What kind of occasion is the cable tray suitable for?

The cable bridge is suitable for the 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 of telecommunications, radio and television departments.

 

3. Types of cable accessories

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. The meaning of the middle joint of the cable

The device that connects the cable and the conductor, insulation shielding layer and protective layer of the cable to connect the cable line is called the cable intermediate joint.

 

5. What is the electrical main connector?

The electrical main wiring is the connection method between the main electrical equipment and the busbar in the power plant and substation, including the connection method between the main busbar and the factory power system according to certain functional requirements.

 

6. What regulations should be followed when selecting the section of the power cable?

  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 stability requirements when the power supply system is short-circuited;

(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 protective device to operate reliably.

 

7. What are the advantages of XLPE cables and oil-paper cables?

(1) Easy to install, because it allows small minimum bending radius and light weight;

(2) Not restricted by line drop;

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

(4) The cable accessories are simple and all of them are of dry structure;

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

(6) The price is lower;

(7) High reliability and low failure rate;

(8) The manufacturing process is less, the process is simple, and the economic benefit is remarkable.

 

8. What are the requirements for clamps for fixing AC single-core cables? Why?

The clamp should have no iron parts to form a closed magnetic circuit. This is because when the cable core passes current, magnetic force lines are generated around it, and the magnetic force lines are proportional to the current passing through the core. It can be seen that eddy currents will be generated in the iron parts to make the cables heat up and even burn out the cables. Therefore, iron parts cannot be used as fixing fixtures for single-core AC cables.