What Are The Measures For Cable Fire Protection?

1. What are the measures for cable fire prevention?

(1) Use flame retardant cables;

(2) The use of fire-resistant cable brackets;

(3) The use of fire retardant coatings;

(4) Fire partition walls and fire baffles are set at cable tunnels, mezzanine exits, etc.;

(5) Overhead cables should avoid oil pipelines and explosion-proof doors, otherwise local pipe penetrations or thermal insulation and fire prevention measures should be taken.

2. Which aspects should be considered when selecting the cross section of the power cable?

(1) The long-term allowable working current of the cable;

(2) Thermal stability in the event of a short circuit;

(3) The voltage drop on the line cannot exceed the allowable working range.

3. What are the advantages of power cables compared with overhead lines?

(1) Reliable operation, because it is installed in hidden places such as underground, it is less damaged by external forces, less chance of failure, safe power supply, and will not cause harm to people;

(2) The maintenance workload is small, and frequent inspections are not required;

(3) There is no need to erect towers;

(4) Helps to improve the power factor.

4. Where are the inner shielding layer and outer shielding layer of the power cable? What material is used? What is the function? In order to make the insulation layer and the cable conductor have better contact, eliminate the conductor surface electric field strength caused by the unsmooth surface of the conductor Generally, the inner shielding layer of metallized paper or semiconductor paper tape is wrapped on the conductor surface. In order to make the insulating layer and the metal sheath have better contact, generally there is an outer shielding layer on the outer surface of the insulating layer. The material of the outer screen layer is the same as that of the inner screen layer, and sometimes copper tape or braided copper ribbon is also attached.

5. What requirements should the control secondary circuit wiring meet?

(1) The construction wiring is correct according to the drawing;

(2) The electrical connection of the wires should be firm and reliable;

(3) The wires in the panel should not have joints, and the core wires of the wires should not be damaged;

(4) The end of the cable core wire should be marked with its circuit number, the number should be correct, the handwriting should be clear and not easy to decolorize;

(5) The wiring should be neat, clear and beautiful, and the wire insulation should be good and non-destructive;

(6) There should be one wire on each side of each terminal, and no more than two at most.

6. What should be paid attention to when using the electric pipe bender to bend the cable protection pipe?

(1) The pipe bending machine should be operated by personnel who understand its performance and are familiar with the operation knowledge;

(2) It must be checked before use, the button, operating handle and travel switch should be in good condition, and the pipe bender must be reliably grounded;

(3) Select the mold that meets the requirements, and determine the required bending radius;

(4) There should be sufficient scope of activities around the construction site;

(5) When using, it can only work with load after the idling is normal. During operation, it is strictly forbidden to touch the rotating part with hands and feet;

(6) After the work is completed, the power should be cut off in time and the oil pressure should be released.