Cable protection regulations

1. What are the advantages of cross-linked heat shrinkable cable accessories?

Answer: This is a new type of material, which has advantages such as superior electrical performance, small size, small quality, easy installation, and material matching compared to other types of accessories nowadays. In addition, it also has the ability to withstand climate, dirt, and flame retardant self-extinguishing.

2. What are the requirements for the mechanical strength of the cable conductor connection points?

Answer: The mechanical strength of the connection point is generally lower than the tensile strength of the cable conductor itself. For fixed laying power cables, the tensile strength of the connection point is required to be no less than 60% of the tensile strength of the conductor itself.

3. What are the main properties of the insulating layer material for power cables?

Answer:; It shall have the following main performances: ① High breakdown strength; ② Low dielectric loss; ③ Relatively high insulation resistance; ④ Excellent discharge resistance; ⑤ Has a certain degree of softness and mechanical strength; ⑥ The insulation performance is stable for a long time.

4. When laying cables mechanically, what are the regulations for traction strength?

Answer: For copper core cables, when pulling the head, the allowable traction strength is 70N/cm; For aluminum core cables, when pulling the head, the allowable traction strength is 40N/cm;  When using a steel mesh sleeve for traction, the allowable strength of the lead sheathed cable is 10N/cm; The lead sheathed cable is 40 N/cm.

5. What are the regulations for cable protection tubes?

Answer: ① When cables need to be laid through protective pipes, the inner diameter of the pipe should not be less than 1.5 times the outer diameter of the cable, and the inner diameter of concrete pipes, clay pipes, asbestos, and cement pipes should not be less than 100mm; ② The bending radius of the cable conduit shall comply with the regulations on the bending radius of the cable penetrated; ③ Each pipe should have a maximum of three bends and no more than two right angle bends.

6. How to measure the outer diameter of the cable sheath?

Answer: Measure the outer diameter of the sheath and its average value at five evenly distributed points on the circumference of the sheath. The average outer diameter is both the outer diameter of the sheath.

7. How to connect copper core cables with different cross sections?

Answer: For connection of copper core cables with different cross sections, open weak back copper pipes can be used for connection by soldering, or pure copper rods can be connected into copper pipes according to different cross section requirements for connection by crimping.