Installation Methods and Requirements for Power Cable Lines

Installation methods for power cable lines

(1) Directly buried underground, this is a very simple installation method.

(2) Installed within cable trenches for laying multiple cables.

The cable trench, although initially requiring a higher investment than direct burial, offers ease in temperature monitoring and the implementation of ventilation and cooling measures, thereby improving its heat dissipation conditions. Additionally, East China Cable believes that the cable trench also facilitates cable maintenance, installation, replacement, and is advantageous in preventing external damage and aiding in fault detection and repair.

(3) When laying cables in areas with a high concentration of outgoing cables from power plants or substations, or where multiple parallel cables are installed (such as 20 to over 40), it is advisable to consider constructing a cable tunnel.

Constructing cable tunnels, though they require significant investment, long construction periods, and substantial material consumption, and also present challenges such as ventilation, fire prevention, and waterproofing, offer the following advantages:

1) Significantly reduced the road cross-section (right-of-way) occupied by cable lines.

2) Minimize external force damage and mechanical wear to cables.

3) Eliminate chemical corrosion of the protective layer caused by harmful substances in the soil.

4) Quick and easy cable maintenance or replacement.

5) New cables can be added at any time without having to dig up the road surface.

(4) Installed within cable conduits, when a large number of cables pass through urban streets, direct burial can exert significant pressure on the cables and is not suitable for constructing cable trenches or tunnels. Building cable conduits offers a cost-effective alternative to tunnels, while still enjoying many of the same benefits. Additionally, fire safety concerns are not a factor.

(5) Installed on cable supports, this represents a new form of cable installation within the factory area. There are many pipelines within the factory, especially in power plants or chemical factories, making it difficult to lay cable trenches. Moreover, cables are often damaged due to steam or water leakage from hot pipes. Therefore, cable supports are used to elevate the cables in the factory area, replacing the cable trenches.

(6) With the advancement of plastic cables in recent years, overhead cable installations have become more prevalent, as the weight of cables has decreased. Hanging cables from suspension lines (or fixing them to towers) is becoming a standard practice. Compared to underground cables, overhead cables are more susceptible to external influences and lack aesthetic appeal, but they are less expensive to install.

Safety Technical Requirements for the Installation of Power Cable Lines

Safety Technical Requirements for Direct Burial of Cables

1) The burial depth of the cable should not be less than 0.7 meters, and at least 1.2 meters when passing through farmland. Fine soil should be spread around the cable, with a thickness of 100mm. A cement protective plate should be placed 100mm above the cable, extending 50mm beyond the diameter on both sides of the cable.

2) When laying cables near buildings, the distance between the cable sheath and the building foundation should not be less than 0.6 meters (the principle is to ensure that cable installation is not obstructed by the building and does not affect the building's structure).