The most common method of laying cables is to install them in pre prepared trenches. It can protect cables from environmental factors and minimize the possibility of damage caused by external influences.
How to install underground wire
When planning the installation location of underground cable lines, you need to consider the presence of trees and the expected load level on the ground. You should choose an area without tree roots nearby and with the lowest ground load.
It is necessary to carefully study the geological foundation of the area and ensure that the laid route does not cross the existing engineering system.
If multiple underground electrical cables are installed, their lines should not intersect with each other.
After the preliminary work is completed, we can start preparing the trench. The depth of the ditch directly depends on external factors affecting the Earth's surface: if the underground electrical cable line is laid under a lawn, a ditch depth of 0.9m is sufficient; If the direct burial cable is laid under the highway, the depth of the ditch should be at least 0.9m. It requires a depth of 1.25 meters. After removing the remaining soil and debris from the ditch, it is necessary to pour a layer of 0.15 m thick sand, and it is important that the sand evenly covers the entire bottom.
Types of buried cables
The most important factor determining the service life and characteristics of a conductor is the insulation material
1. Impregnated paper insulation can provide excellent electrical performance and a longer service life at low cost. The disadvantage of this insulation is its low moisture resistance and the need for a completely sealed outer shell. In addition, significant differences in the depth of installation of different parts of the direct burning wire can cause the impregnated composite to flow to the lower area, thereby reducing insulation strength and shortening service life.
2. Plastic insulator: made of polyvinyl chloride or polyethylene. Cables can be laid in harsh environments with high humidity or fire hazards.
When laid in soil with enhanced corrosion, a metal clad cable should be used.
3.If there is a risk of mechanical damage to the conductor, a swa armed cable or a sta power cable should be used
4.Lay the direct thermal electrical cable in the form of a "wavy" line directly into the prepared trench without tensioning. If multiple conductors are laid in the ditch, their spacing should be 0.1m.
Cover a layer of 0.1m thick sand on the direct burial cable, then cover a layer of soil about 0.15m thick and thoroughly compact it.
Warning tape with warning text is installed on the ground, strictly installed in the area where the direct burning wire passes through, and the ditch is filled with soil and carefully compacted.
