How to properly install power cables?

With the rapid development of my country's economy and the continuous expansion of cities, a large number of power cables have been put into use, so there are more and more failures. Since the failure of power cables is directly related to the safe operation of the entire power system, in order to improve To use electricity well and safely, we need to ensure the correct installation and use of power cables.

Correct installation of power cables

1. Conductor connection

The conductor connection requires low resistance and sufficient mechanical strength. Therefore, sharp corners must not appear at the connection of the power cable, otherwise it will affect the performance of the power cable.

Moreover, when connecting medium and low voltage cable conductors with crimp connection, attention should be paid to:

(1) Select a conductor connecting tube with appropriate electrical conductivity and mechanical strength, that is, the matching gap between the inner diameter of the crimping tube and the outer diameter of the connected core is 0.8 to 1.4 mm.

(2) Before the medium and low voltage cable conductors are crimped, apply conductive glue on the outer surface of the conductor and the inner surface of the connecting tube, and use a wire brush to destroy the oxide film. Smooth with a file or sandpaper.

2. Metal shielding and grounding treatment

The role of metal shielding in cables is mainly to conduct short-circuit current of cable faults and to shield electromagnetic interference from electromagnetic fields to adjacent communication equipment. In the operating state, the metal shield is at zero potential in a good grounded state. When the cable fails, it has the ability to conduct short-circuit current in a very short period of time. Therefore, this requires that the grounding wire of the power cable should be welded reliably, and the metal shielding and armored tapes on the cable body at both ends of the box should be firmly welded. The grounding of the terminal head should be reliable.

3. Sealing and mechanical protection of joints

The sealing and mechanical protection of the joint is the guarantee to ensure the safe and reliable operation of the joint. Therefore, in order to better use the power cable, moisture and moisture should be prevented from infiltrating the joint. For example, the joint protection groove should be built or cement should be installed at the joint. protective box, etc.

Low voltage wire insulation considerations

Low-voltage cables have the following characteristics in actual use:

1. The randomness of laying is relatively large, and the path is not very clear.

2. When laying, it is not like the high-voltage cable, which is filled with sand and bricks and then buried deeply. On the contrary, the buried depth is shallow, and it is easy to be damaged by external force and cause failure.

3. Cables are generally shorter, ranging from tens of meters to hundreds of meters, unlike high-voltage cables that are often hundreds of meters to several kilometers.

4. The requirements for insulation strength are low, and the process is relatively simple when dealing with faults and making joints.

5. The vast majority of cables have obvious burnt damage at the fault point. It is very rare for the fault point to leave no trace on the cable sheath.

6. The load carried varies greatly, and the phases are often unbalanced, which is easy to heat up, and the faults caused by this are mostly common.